CSV files that break parsers

Clean CSV

A clean, well-formed CSV with a header and 20 rows — the baseline case for CSV parser testing.

File: CSV · CSV · 20 rows
Use case: CSV parsingData import

Messy CSV (quoted commas, newlines, ragged rows)

A deliberately messy CSV: a quoted field with a comma, a quoted field with an embedded newline, escaped double-quotes, and ragged rows with too few and too many fields — the cases that break naïve parsers.

File: CSV · CSV · UTF-8
Use case: CSV parsingError handling

Semicolon-Delimited CSV

A CSV that uses semicolons as the delimiter (common in European locales) — for testing delimiter detection.

File: CSV · CSV · 20 rows
Use case: CSV parsing

Tab-Separated Values (TSV)

A tab-separated values file with a header and 20 rows — for testing TSV parsing and delimiter handling.

File: TSV · CSV · 20 rows
Use case: CSV parsing

Headerless CSV

A CSV with no header row — for testing parsers that must infer or be told the column names.

File: CSV · CSV · 20 rows
Use case: CSV parsing

10,000-Row CSV

A CSV with 10,000 data rows — for testing streaming parsers, memory handling, and import performance.

File: CSV · CSV · 10,000 rows
Use case: CSV parsingData import

Latin-1 Encoded CSV

A CSV encoded in Latin-1 (ISO-8859-1) with accented names — for testing encoding detection and mis-decoding (it will look wrong if read as UTF-8).

File: CSV · CSV · 3 rows
Use case: CSV parsingEncoding detection

CSV with Mixed Null Representations

A CSV where missing values are written seven different ways — empty string, NULL, NA, N/A, null, None, and a dash — across text and numeric columns. A fixture for testing null-detection and coercion in CSV importers.

File: CSV · Edge Cases · 8 rows
Use case: CSV parsingError handling+1

CSV with Mixed-Type Columns

A CSV whose 'value' column mixes integers, floats, scientific notation, dates, hex, thousands separators, and whitespace, and whose 'flag' column mixes a dozen boolean spellings. A torture test for type inference and schema detection.

File: CSV · Edge Cases · 12 rows
Use case: CSV parsingError handling+1

Wide CSV — 1000 Columns

A CSV with 1000 columns and a handful of rows — a stress test for parsers, spreadsheet importers, and databases with column limits or per-row buffering assumptions. Deterministic (fixed seed).

File: CSV · Edge Cases · 5 rows
Use case: CSV parsingPerformance testing+1

CSV with Mixed Timestamp Formats

A CSV listing timestamps in eleven formats — ISO 8601 with Z and numeric offsets, millisecond precision, naive local, date-only, Unix epoch in seconds and milliseconds, US AM/PM, and RFC 1123. A fixture for testing date parsing and timezone normalisation.

File: CSV · Edge Cases · 11 rows
Use case: CSV parsingError handling+1

CSV with Duplicate Headers

A small CSV whose header row repeats the column name id — a common importer failure mode.

File: CSV · Edge Cases · 2 rows
Use case: CSV parsingError handling

CSV with Leading-Zero Identifiers

SKU identifiers that start with zeros. Spreadsheet tools often coerce these to numbers and drop the zeros — keep them as text.

File: CSV · Edge Cases · 3 rows
Use case: CSV parsingData import

CSV Formula-Injection Safe Sample

A sanitization-test CSV with one equals-prefixed cell clearly labelled sample-only. Use it to verify importers neutralize spreadsheet formulas — not an attack list.

File: CSV · Edge Cases · 2 rows
Use case: CSV parsingError handling

CSV DST and Leap-Day Timestamps

Timestamps spanning a US spring-forward DST gap and leap-day dates for timezone and calendar edge-case testing.

File: CSV · Edge Cases · 4 rows
Use case: CSV parsingData import

CSV — UTF-8 with BOM

A CSV prefixed with a UTF-8 BOM (EF BB BF) and accented / CJK cells — for testing BOM-aware importers.

File: CSV · Encodings · 3 rows
Use case: CSV parsingEncoding detection+1

CSV — UTF-16 LE with BOM

The same three data rows as UTF-16 little-endian with a BOM — wide-character CSV decoding fixture.

File: CSV · Encodings · 3 rows
Use case: CSV parsingEncoding detection

CSV — UTF-16 BE with BOM

UTF-16 big-endian CSV with BOM — for byte-order detection in tabular importers.

File: CSV · Encodings · 3 rows
Use case: CSV parsingEncoding detection

CSV — Windows-1252 (CP1252)

A CP1252 CSV using the 0x80–0x9F range (smart quotes, euro, bullet) that Latin-1 misreads.

File: CSV · Encodings · 2 rows
Use case: CSV parsingEncoding detection

CSV — Shift-JIS Japanese

A Shift-JIS encoded Japanese CSV — for CJK charset detection and Shift-JIS→UTF-8 conversion in importers.

File: CSV · Encodings · 2 rows
Use case: CSV parsingEncoding detection+1

CSV — Semicolon Delimiter (EU)

European-style CSV using semicolons as delimiters and comma decimals — a common locale edge case.

File: CSV · Encodings · 2 rows
Use case: CSV parsingData import

CSV — Pipe Delimiter

A pipe-delimited (| ) tabular file — for testing non-comma delimiter autodetection.

File: CSV · Encodings · 2 rows
Use case: CSV parsingData import

CSV Extension — Tab Delimited Content

A .csv file whose content is tab-delimited — tests whether importers sniff delimiters or trust the extension.

File: CSV · Encodings · 2 rows
Use case: CSV parsingError handling

Fixed-Width Positions File (TXT)

A classic fixed-width text extract with documented column positions — for COBOL-style / mainframe importer tests.

File: TXT · Encodings · 3 rows
Use case: CSV parsingData import+1

CSV — Quoted Embedded Newlines

A CSV with a quoted field that contains an embedded newline — a classic RFC 4180 parser stress case.

File: CSV · Encodings · 2 rows
Use case: CSV parsingError handling

CSV — Mixed CRLF and LF

A CSV that mixes CRLF and LF row endings within one file — newline normalisation fixture.

File: CSV · Encodings · 3 rows
Use case: CSV parsingEncoding detection

CSV — Ragged Column Counts

Rows with differing field counts — for testing how importers pad, truncate, or error on ragged CSV.

File: CSV · Encodings · 3 rows
Use case: CSV parsingError handling

CSV — Hash Comment Lines

A CSV with # comment lines mixed among data — common in scientific exports; tests comment skipping.

File: CSV · Encodings · 2 rows
Use case: CSV parsingData import

CSV — Single Column

A one-column CSV of email addresses — edge case for delimiter sniffers that expect commas in every row.

File: CSV · Encodings · 2 rows
Use case: CSV parsingData import

CSV — ISO-8859-1 (Latin-1)

A Latin-1 CSV with high-bit accented characters — for legacy 8-bit charset detection.

File: CSV · Encodings · 2 rows
Use case: CSV parsingEncoding detection

SaaS Product Events (CSV)

Synthetic product-analytics events (signup/login/upgrade) for testing event pipelines and warehouse loads. CSV twin.

File: CSV · Saas · 24 rows
Use case: Data importCSV parsing· Conversion set

POS SKU Catalog (CSV)

A point-of-sale SKU catalog with tax codes and active flags — fictional Meridian Supply inventory. CSV twin.

File: CSV · Pos · 8 rows
Use case: Data importCSV parsing· Conversion set

Lab Measurements (CSV)

Synthetic lab readings (temperature, pressure, pH) with ISO timestamps for scientific ETL tests. CSV twin.

File: CSV · Lab · 16 rows
Use case: Data importCSV parsing· Conversion set

Marketing Attribution (CSV)

Synthetic multi-touch attribution click rows with UTM fields — for marketing analytics importers. CSV twin.

File: CSV · Marketing · 10 rows
Use case: Data importCSV parsing· Conversion set

FINANCE — Ledger Lines (CSV)

Synthetic finance dataset (ledger-lines) as CSV — for ETL and warehouse loader tests.

File: CSV · Finance · 8 rows
Use case: Data importCSV parsing· Conversion set

SUPPORT — Tickets (CSV)

Synthetic support dataset (tickets) as CSV — for ETL and warehouse loader tests.

File: CSV · Support · 6 rows
Use case: Data importCSV parsing· Conversion set

Synth Batch 01 (CSV)

Deterministic synthetic CSV batch 01 for bulk-import smoke tests.

File: CSV · Synth · 5 rows
Use case: Data importCSV parsing· Conversion set

Synth Batch 02 (CSV)

Deterministic synthetic CSV batch 02 for bulk-import smoke tests.

File: CSV · Synth · 5 rows
Use case: Data importCSV parsing· Conversion set

Synth Batch 03 (CSV)

Deterministic synthetic CSV batch 03 for bulk-import smoke tests.

File: CSV · Synth · 5 rows
Use case: Data importCSV parsing· Conversion set

Synth Batch 04 (CSV)

Deterministic synthetic CSV batch 04 for bulk-import smoke tests.

File: CSV · Synth · 5 rows
Use case: Data importCSV parsing· Conversion set

Synth Batch 05 (CSV)

Deterministic synthetic CSV batch 05 for bulk-import smoke tests.

File: CSV · Synth · 5 rows
Use case: Data importCSV parsing· Conversion set

Synth Batch 06 (CSV)

Deterministic synthetic CSV batch 06 for bulk-import smoke tests.

File: CSV · Synth · 5 rows
Use case: Data importCSV parsing· Conversion set

Synth Batch 07 (CSV)

Deterministic synthetic CSV batch 07 for bulk-import smoke tests.

File: CSV · Synth · 5 rows
Use case: Data importCSV parsing· Conversion set

Synth Batch 08 (CSV)

Deterministic synthetic CSV batch 08 for bulk-import smoke tests.

File: CSV · Synth · 5 rows
Use case: Data importCSV parsing· Conversion set

Synth Batch 09 (CSV)

Deterministic synthetic CSV batch 09 for bulk-import smoke tests.

File: CSV · Synth · 5 rows
Use case: Data importCSV parsing· Conversion set

Synth Batch 10 (CSV)

Deterministic synthetic CSV batch 10 for bulk-import smoke tests.

File: CSV · Synth · 5 rows
Use case: Data importCSV parsing· Conversion set

Synth Batch 11 (CSV)

Deterministic synthetic CSV batch 11 for bulk-import smoke tests.

File: CSV · Synth · 5 rows
Use case: Data importCSV parsing· Conversion set

Synth Batch 12 (CSV)

Deterministic synthetic CSV batch 12 for bulk-import smoke tests.

File: CSV · Synth · 5 rows
Use case: Data importCSV parsing· Conversion set

Synth Batch 13 (CSV)

Deterministic synthetic CSV batch 13 for bulk-import smoke tests.

File: CSV · Synth · 5 rows
Use case: Data importCSV parsing· Conversion set

Synth Batch 14 (CSV)

Deterministic synthetic CSV batch 14 for bulk-import smoke tests.

File: CSV · Synth · 5 rows
Use case: Data importCSV parsing· Conversion set

Synth Batch 15 (CSV)

Deterministic synthetic CSV batch 15 for bulk-import smoke tests.

File: CSV · Synth · 5 rows
Use case: Data importCSV parsing· Conversion set

Synth Batch 16 (CSV)

Deterministic synthetic CSV batch 16 for bulk-import smoke tests.

File: CSV · Synth · 5 rows
Use case: Data importCSV parsing· Conversion set

Synth Batch 17 (CSV)

Deterministic synthetic CSV batch 17 for bulk-import smoke tests.

File: CSV · Synth · 5 rows
Use case: Data importCSV parsing· Conversion set

Synth Batch 18 (CSV)

Deterministic synthetic CSV batch 18 for bulk-import smoke tests.

File: CSV · Synth · 5 rows
Use case: Data importCSV parsing· Conversion set

Synth Batch 19 (CSV)

Deterministic synthetic CSV batch 19 for bulk-import smoke tests.

File: CSV · Synth · 5 rows
Use case: Data importCSV parsing· Conversion set

Synth Batch 20 (CSV)

Deterministic synthetic CSV batch 20 for bulk-import smoke tests.

File: CSV · Synth · 5 rows
Use case: Data importCSV parsing· Conversion set

HR — Employees Mini (CSV)

Synthetic hr dataset (employees-mini) as CSV — for ETL and warehouse loader tests.

File: CSV · Hr · 8 rows
Use case: Data importCSV parsing· Conversion set

IOT — Sensor Readings Mini (CSV)

Synthetic iot dataset (sensor-readings-mini) as CSV — for ETL and warehouse loader tests.

File: CSV · Iot · 12 rows
Use case: Data importCSV parsing· Conversion set

Time-series — Irregular Intervals (CSV)

Sensor readings at irregular minute gaps — tests time-series resampling and gap detection.

File: CSV · Timeseries · 8 rows
Use case: Time-series dataData import+1· Conversion set

Time-series — Irregular Intervals (JSON)

JSON twin of irregular-interval sensor readings for charting library tests.

File: JSON · Timeseries · 8 records
Use case: Time-series dataData import+1· Conversion set

Time-series — DST Spring Forward Gap (CSV)

Hourly load data skipping the 03:00 hour on DST spring-forward day — tests timezone/DST gap handling.

File: CSV · Timeseries · 4 rows
Use case: Time-series dataData import+1

Time-series — DST Fall Back Duplicate Hour (CSV)

Load readings with a repeated 01:00 local hour on fall-back DST — tests ambiguous timestamp handling.

File: CSV · Timeseries · 5 rows
Use case: Time-series dataData import+1

Time-series — Duplicate Timestamp Keys (CSV)

Two rows share the same timestamp key — tests deduplication and last-write-wins policies.

File: CSV · Timeseries · 3 rows
Use case: Time-series dataData import+2· Conversion set

Time-series — Duplicate Timestamp Keys (JSON)

JSON array with duplicate timestamp keys for ingestion pipeline tests.

File: JSON · Timeseries · 3 records
Use case: Time-series dataData import+1· Conversion set

Time-series — Gap Filled

Series with an explicit null value at a missing sample point.

File: CSV · Timeseries · 3 rows
Use case: Time-series dataData import+1

Time-series — Out Of Order

Timestamps out of chronological order — tests sort-on-ingest behaviour.

File: CSV · Timeseries · 3 rows
Use case: Time-series dataData import+1

Time-series — Mixed Tz

Same nominal instant expressed in Z, -05:00, and +09:00 offsets.

File: JSON · Timeseries · 3 rows
Use case: Time-series dataData import+1

Time-series — Nan Gaps

CSV with NaN string and empty cells representing missing measurements.

File: CSV · Timeseries · 3 rows
Use case: Time-series dataData import+1

Time-series — Millisecond

Sub-second millisecond timestamps for precision parsing tests.

File: JSON · Timeseries · 2 rows
Use case: Time-series dataData import+1

Time-series — Business Hours

Hourly order counts weekdays only (09–16 UTC) across three SAMPLE days.

File: CSV · Timeseries · 24 rows
Use case: Time-series dataData import+1

Time-series — Weekly Agg

Pre-aggregated weekly totals JSON for rollup/chart tests.

File: JSON · Timeseries · 1 row
Use case: Time-series dataData import+1

Time-series — Leap Day

Readings spanning Feb 29 leap day — calendar edge case.

File: CSV · Timeseries · 2 rows
Use case: Time-series dataData import+1

Time-series — Epoch Boundary

Timestamps at Unix epoch and classic 32-bit Y2038 boundary.

File: JSON · Timeseries · 2 rows
Use case: Time-series dataData import+1

Time-series — Sparse Events (JSONL)

Sparse event log in JSON Lines — two events hours apart for event-stream ingestion tests.

File: JSONL · Timeseries · 2 records
Use case: Time-series dataData import+2

Healthcare Patient Demographics (CSV)

Synthetic patient demographics CSV for EHR import and de-identification pipeline tests.

File: CSV · Healthcare · 2 rows
Use case: Data importCSV parsing

Healthcare Lab Results (CSV)

Synthetic lab result rows for clinical data warehouse import tests.

File: CSV · Healthcare · 2 rows
Use case: Data importCSV parsing

Fintech Transaction History (CSV)

Synthetic bank transaction history for personal-finance importer tests.

File: CSV · Fintech · 2 rows
Use case: Data importCSV parsing

Inventory SKU Catalog (CSV)

Fictional SKU catalog for ERP and POS import tests.

File: CSV · Inventory · 2 rows
Use case: Data importCSV parsing

Inventory Cycle Count (CSV)

Cycle-count variance SAMPLE for inventory audit reconciliation tests.

File: CSV · Inventory · 1 row
Use case: Data importCSV parsing

CSV Edge — Semicolon Eu

Tiny SAMPLE CSV (semicolon-eu) exercising delimiter/quoting edge behaviour.

File: CSV · CSV
Use case: CSV parsingError handling+1· Conversion set

CSV Edge — Pipe Delimited

Tiny SAMPLE CSV (pipe-delimited) exercising delimiter/quoting edge behaviour.

File: CSV · CSV
Use case: CSV parsingError handling+1· Conversion set

CSV Edge — Hash Commented

Tiny SAMPLE CSV (hash-commented) exercising delimiter/quoting edge behaviour.

File: CSV · CSV
Use case: CSV parsingError handling+1· Conversion set

CSV Edge — Quoted Embedded Comma

Tiny SAMPLE CSV (quoted-embedded-comma) exercising delimiter/quoting edge behaviour.

File: CSV · CSV
Use case: CSV parsingError handling+1· Conversion set

CSV Edge — Quoted Embedded Newline

Tiny SAMPLE CSV (quoted-embedded-newline) exercising delimiter/quoting edge behaviour.

File: CSV · CSV
Use case: CSV parsingError handling+1· Conversion set

CSV Edge — Empty Fields

Tiny SAMPLE CSV (empty-fields) exercising delimiter/quoting edge behaviour.

File: CSV · CSV
Use case: CSV parsingError handling+1· Conversion set

CSV Edge — Trailing Comma

Tiny SAMPLE CSV (trailing-comma) exercising delimiter/quoting edge behaviour.

File: CSV · CSV
Use case: CSV parsingError handling+1· Conversion set

CSV Edge — Header Only

Tiny SAMPLE CSV (header-only) exercising delimiter/quoting edge behaviour.

File: CSV · CSV
Use case: CSV parsingError handling+1· Conversion set

CSV Edge — Single Column

Tiny SAMPLE CSV (single-column) exercising delimiter/quoting edge behaviour.

File: CSV · CSV
Use case: CSV parsingError handling+1· Conversion set

CSV Edge — Mixed Quoting

Tiny SAMPLE CSV (mixed-quoting) exercising delimiter/quoting edge behaviour.

File: CSV · CSV
Use case: CSV parsingError handling+1· Conversion set

Multi-Currency Invoice Ledger (CSV, SAMPLE)

CSV twin of the multi-currency SAMPLE invoice ledger.

File: CSV · Invoice
Use case: TemplatesCSV parsing· Conversion set

Meeting Action Items (CSV, SAMPLE)

CSV action-item export twin for the SAMPLE meeting notes.

File: CSV · Meeting · 3 rows
Use case: TemplatesCSV parsing· Conversion set

OKR Sheet (CSV, SAMPLE)

CSV twin of the SAMPLE OKR sheet.

File: CSV · OKR
Use case: TemplatesCSV parsing· Conversion set

DPA Annex — Subprocessors (CSV, SAMPLE)

CSV Annex A twin listing fictional SAMPLE subprocessors for the deep DPA.

File: CSV · DPA Annex · 3 rows
Use case: TemplatesPrivacy export testing+1· Conversion set

Employment I-9 Style Sample Export (CSV)

SAMPLE CSV export row for the employment form submission shape.

File: CSV · Employment
Use case: Form testingCSV parsing

Residential Lease Sample Export (CSV)

SAMPLE CSV export row for the housing form submission shape.

File: CSV · Housing
Use case: Form testingCSV parsing

Donation Pledge Sample Export (CSV)

SAMPLE CSV export row for the nonprofit form submission shape.

File: CSV · Nonprofit
Use case: Form testingCSV parsing

Event RSVP Sample Export (CSV)

SAMPLE CSV export row for the events form submission shape.

File: CSV · Events
Use case: Form testingCSV parsing

Wire / ACH Transfer Sample Export (CSV)

SAMPLE CSV export row for the finance form submission shape.

File: CSV · Finance
Use case: Form testingCSV parsing

Student Enrollment Sample Export (CSV)

SAMPLE CSV export row for the education form submission shape.

File: CSV · Education
Use case: Form testingCSV parsing

Parking Permit Sample Export (CSV)

SAMPLE CSV export row for the parking form submission shape.

File: CSV · Parking
Use case: Form testingCSV parsing

Event Guest List (CSV)

SAMPLE CSV export row for the events form submission shape.

File: CSV · Events
Use case: Form testingCSV parsing

HTML5 Constraint Attributes (CSV)

A flat table of the HTML5 constraint attributes: what each applies to, whether the browser enforces it, whether it blocks submission, and one valid and one invalid example. The spreadsheet-shaped twin of the JSON constraint rules.

File: CSV · Form Data · 18 rows
Use case: Form parsingForm testing+1

Input Type Attribute Matrix (CSV)

Twenty input types crossed with the seven attributes that may or may not apply to them, so a form builder can be checked for attributes it emits on controls that ignore them.

File: CSV · Form Data · 20 rows
Use case: Form parsingForm testing+1

Autocomplete Tokens (CSV)

The autofill tokens as a flat table with their group, the prefixes each accepts, the control type they usually sit on and a sample value. Useful for driving a data-driven autofill test.

File: CSV · Form Data · 25 rows
Use case: Form parsingForm testing+1

Form Field Name Edge Cases (CSV)

Fifteen awkward field names with the urlencoded key each produces: brackets, array notation, spaces, plus signs, ampersands, equals signs and three non-ASCII scripts including an astral emoji.

File: CSV · Form Data · 15 rows
Use case: Form parsingForm testing+1

Form Submissions Batch (CSV)

Twelve fictional submissions in one export, including values with commas, embedded quotation marks, an embedded newline, an empty cell and non-ASCII text. Sized for testing an importer rather than a database.

File: CSV · Form Data · 12 rows
Use case: Form parsingForm testing+1

Column Count Mismatch (intentionally corrupt CSV)

Intentionally corrupt. A submissions export whose header declares eight columns while its three data rows carry six, ten and eight, so a reader has to choose between padding, truncating and refusing.

File: CSV · Form Data
Use case: Form parsingForm testing+1

GDPR Export — CSV Heavy (ZIP, SAMPLE)

SAMPLE GDPR-style ZIP dominated by activity/devices/sessions CSVs — fictional PII.

File: ZIP · Exports · 4 members
Use case: Privacy export testingCSV parsing+1

GDPR Devices Export (CSV, SAMPLE)

SAMPLE devices CSV twin for privacy-export tooling.

File: CSV · Exports · 2 rows
Use case: Privacy export testingCSV parsing

Confusion Matrix — 3-class (CSV)

A 3-class confusion matrix as CSV — rows are the true class, columns the predicted class, cells the counts. Paired with a JSON twin for testing metric parsers and evaluation visualisers.

File: CSV · Eval
Use case: Model evaluationCSV parsing+1· Paired fixture

ROC Curve Points (CSV)

An ROC curve as CSV — decision threshold with the corresponding false-positive and true-positive rates, monotonic from (0,0) to (1,1). A fixture for testing chart tools and AUC calculators.

File: CSV · Eval
Use case: Model evaluationCSV parsing+1

Confusion Matrix — 3 Classes (CSV)

3×3 confusion matrix CSV for classification metric calculators.

File: CSV · Eval
Use case: Model evaluationCSV parsing· Conversion set

CLDR Plural-Category Matrix — six languages

One row per language, one column per CLDR plural category, filled with the smallest integers that select it — the sheet to hand a translator or a PM when explaining why 'one' and 'other' is not enough. Japanese needs one form and Welsh needs six.

File: CSV · Cldr · 6 rows
Use case: InternationalizationLocalization catalogs+1

Bidi Test-Case Matrix — eight rendering cases

A flat index of the bidi cases in this wave — which mark each one uses, what it should render as, and why the neutral characters involved need help. Row b8 is the control case with no marks, against which the other seven are compared.

File: CSV · Bidi · 8 rows
Use case: InternationalizationCSV parsing+1

Locale Number Formats — twelve locales (CSV)

The same number, 1234567.89, rendered for twelve locales, with the group and decimal separator that produced each one named by code point and present literally in the cell. Four of the separators are not ASCII — U+00A0, U+202F, U+2019 and U+066C — and ar-EG additionally switches the digits themselves.

File: CSV · Formatting · 12 rows
Use case: InternationalizationCSV parsing+1· Conversion set

Locale Currency Formats — eleven locales (CSV)

12345.60 in each locale's own currency, with the fraction-digit count and the symbol placement that produced it. JPY takes zero decimals and rounds; six rows separate the amount from the symbol with U+00A0 rather than a plain space; and ar-EG puts the amount in Arabic-Indic digits.

File: CSV · Formatting · 11 rows
Use case: InternationalizationCSV parsing+1· Conversion set

Locale Date and Time Patterns — ten locales (CSV)

Short and medium date patterns, the short time pattern and the hour cycle for ten locales, each with the rendering of 2026-03-14T09:05. The ar-EG patterns contain U+200F between their fields and ru-RU's medium pattern ends in a quoted literal, so neither is the plain ASCII it appears to be.

File: CSV · Formatting · 10 rows
Use case: InternationalizationCSV parsing+1· Conversion set

Flaky Run — Timing Race, Flake-Rate Table (CSV)

The answer key for the timing race family: the flake rate a detector should derive from the five build reports next to it. Exactly one of the six tests is unstable, at a rate of 2/5; the other five are stable at 0.00.

File: CSV · Flaky Runs · 6 rows
Use case: CSV parsingConversion testing+1· Conversion set

Flaky Run — Order Dependent, Flake-Rate Table (CSV)

The answer key for the order dependent family: the flake rate a detector should derive from the five build reports next to it. Exactly one of the six tests is unstable, at a rate of 2/5; the other five are stable at 0.00.

File: CSV · Flaky Runs · 6 rows
Use case: CSV parsingConversion testing+1· Conversion set

Flaky Run — Network Dependency, Flake-Rate Table (CSV)

The answer key for the network dependency family: the flake rate a detector should derive from the five build reports next to it. Exactly one of the six tests is unstable, at a rate of 2/5; the other five are stable at 0.00.

File: CSV · Flaky Runs · 6 rows
Use case: CSV parsingConversion testing+1· Conversion set

Flaky Run — Quarantined After Two Failures, Flake-Rate Table (CSV)

The answer key for the quarantined after two failures family: the flake rate a detector should derive from the five build reports next to it. Exactly one of the six tests is unstable, at a rate of 5/5; the other five are stable at 0.00.

File: CSV · Flaky Runs · 6 rows
Use case: CSV parsingConversion testing+1· Conversion set

Flaky Detection — Per-Test Failure-Rate Summary (CSV)

The aggregate answer key for the 40-build history in this group: runs, passes, failures and failure rate per test, with each test labelled stable or flaky. Use it to score a detector rather than eyeballing 240 JSONL records.

File: CSV · Flaky Runs · 6 rows
Use case: CSV parsingConversion testing+1· Conversion set

Coverage — Per-File Table (CSV)

The same coverage as a flat table with a TOTAL row, for spreadsheets, trend charts and diffing two runs without an XML parser. The TOTAL row is the arithmetic sum of the four file rows, so it doubles as a checksum on any tool that regenerates it. Every file in this group describes the same four-file source tree and reports 127/140 lines, 17/24 branch outcomes and 18/20 functions, so a converter can be diffed against a known answer.

File: CSV · Coverage · 5 rows
Use case: CSV parsingConversion testing+1· Conversion set

Load Test — Per-Request Log (CSV)

Three hundred individual request records with timestamp, scenario, status and duration — the raw log a percentile calculation has to be computed from rather than read off. A handful of 4xx and 5xx responses are mixed in so an error-rate calculation has something to find.

File: CSV · Performance · 300 rows
Use case: Performance testingCSV parsing+1· Conversion set

Load Test — Latency Percentiles by Scenario (CSV)

The percentile table a performance report renders as a chart, with mean, p50, p95, p99 and max for each of the four scenarios. The same numbers appear inside the JSON summary in this group, so a chart built from either source can be diffed against the other.

File: CSV · Performance · 4 rows
Use case: Performance testingCSV parsing+1· Conversion set

Test Case Matrix — Twelve Documented Cases (CSV)

Twelve test cases with level, priority, the requirement each covers, preconditions, steps and expected result — the table a test-management import expects. Eleven of the twelve are automated, and the requirement column joins this file to the traceability matrix next to it.

File: CSV · Plans · 12 rows
Use case: CSV parsingData import+1· Conversion set

Requirements Traceability Matrix with One Gap (CSV)

Thirteen requirements mapped to the test cases that cover them — and one, REQ-PAY-02, deliberately covered by nothing. A coverage-gap report that does not surface that row is not working, which makes this the answer key for exactly that check.

File: CSV · Plans · 13 rows
Use case: CSV parsingData import+1· Conversion set

Trace Span Table — Flat CSV Export (csv)

The same 13 spans flattened to a CSV table — span and parent IDs, service, name, kind, start timestamp, duration and status. The shape a trace store exports for spreadsheet analysis, and a readable ground truth to diff the three JSON twins against.

File: CSV · Traces · 13 rows
Use case: ObservabilityCSV parsing+1· Conversion set

Metric Range Export — Long (Tidy) CSV (csv)

The same 90 samples as the query_range response, exported one row per observation with both epoch and ISO 8601 timestamps. The long layout every dataframe library prefers, and half of a reshaping pair.

File: CSV · Metrics · 90 rows
Use case: ObservabilityCSV parsing+1· Conversion set

Metric Range Export — Wide (Pivoted) CSV (csv)

The same 90 samples pivoted to one column per service and one row per timestamp — the layout a spreadsheet chart expects. Paired with the long-format export so a reshape can be scored in both directions.

File: CSV · Metrics · 30 rows
Use case: ObservabilityCSV parsing+1· Conversion set

SLO Error Budget — 28-Day Burndown Export (csv)

A day-by-day burndown of the availability SLO defined in the OpenSLO fixture: achieved ratio, budget consumed and remaining, and one-hour and six-hour burn rates. Consumption is monotonic across the window, which is the invariant a burn-rate chart must not violate.

File: CSV · Alerts · 28 rows
Use case: ObservabilityCSV parsing+1· Conversion set

SBOM Component Inventory (CSV)

The same fictional component tree flattened to a spreadsheet-friendly CSV — name, version, licence, depth, purl and a SHA-256 prefix — for testing the export path SBOM tools offer alongside JSON. Every package, version, hash and licence is fictional — the tree describes nothing real.

File: CSV · Sbom · 10 rows
Use case: CSV parsingData import+1· Conversion set

Lockfile Pin Summary (CSV)

Declared range against resolved version for every fictional package pinned by the lockfiles in this category — the table a review needs to see which pins drifted from their manifest ranges. Every package, version, hash and licence is fictional — the tree describes nothing real.

File: CSV · Lockfiles · 9 rows
Use case: CSV parsingData import+1· Conversion set

Vulnerability Summary (CSV)

The four SAMPLE advisories flattened to one row each — the export a security review circulates, and the reference answer for any converter run against the Trivy, Grype or OSV reports here. Advisory identifiers use the invented NOVUS-SAMPLE namespace with SAMPLE-CVE aliases; no identifier here refers to a published CVE, GHSA or OSV record, and no package named exists.

File: CSV · Vulnerability · 4 rows
Use case: CSV parsingData import+1· Conversion set

Severity Scoring and SLA Matrix (CSV)

A severity-band table mapping CVSS ranges to remediation SLAs and gate actions, with the finding count each band has in this fixture set — so a policy engine can be tested end to end. Advisory identifiers use the invented NOVUS-SAMPLE namespace with SAMPLE-CVE aliases; no identifier here refers to a published CVE, GHSA or OSV record, and no package named exists.

File: CSV · Vulnerability · 5 rows
Use case: CSV parsingConfig testing+1· Conversion set

SLSA Build Level Matrix (CSV)

How the nine fictional dependencies distribute across SLSA build levels, with the policy outcome for each band — the table that turns the VSA's dependencyLevels object into something reviewable. Every package, version, hash and licence is fictional — the tree describes nothing real.

File: CSV · Provenance · 4 rows
Use case: CSV parsingData import+1· Conversion set

Transitive Dependency Closure (CSV)

Every edge in the fictional dependency graph as one row — parent, child, declared range, resolved version, depth and whether the edge is direct — the form a spreadsheet or SQL import can aggregate. Every package, version, hash and licence is fictional — the tree describes nothing real.

File: CSV · Graphs · 10 rows
Use case: CSV parsingGraph data+1· Conversion set

Kestrel Bay Towns — Longitude/Latitude CSV

The five towns as a plain CSV with separate longitude and latitude columns — the most common way point data actually arrives. Convert it to GeoJSON and diff against the Point features in the master to score column-order and axis-order handling.

File: CSV · Territory · UTF-8
Use case: GeospatialCSV parsing+1· Conversion set

Kestrel Bay Territory — CSV with a WKT Geometry Column

Attributes plus a quoted WKT geometry column — the shape PostGIS `COPY`, DuckDB spatial and QGIS delimited-text imports expect. The geometry field contains commas, so it exercises quoted-field parsing as well as geometry decoding.

File: CSV · Territory · 14 records
Use case: GeospatialCSV parsing+1· Conversion set

Reprojection Control Points — 4326 to 3857 and 4087

Nine control points — the five towns plus Null Island, the equator, a high-latitude point and the Web Mercator latitude limit — with their coordinates in both projections. The two target projections share the x formula and differ only in y, which isolates a latitude-transform bug from a longitude one.

File: CSV · Crs · 9 rows
Use case: GeospatialCSV parsing+1· Conversion set

Coordinate Precision — Decimal Places to Metres Reference

What each decimal place is actually worth on the ground, computed on a sphere of mean Earth radius at the territory's latitude. Longitude degrees are shorter than latitude degrees by the cosine of the latitude, which is why the two columns diverge.

File: CSV · Precision · 10 rows
Use case: GeospatialCSV parsing+1· Conversion set

Signed Zero Round-Trip Through Text (.csv)

Nine ways of writing zero, what each parses to, and what dividing one by the result gives. Negative zero compares equal to positive zero yet behaves differently in division and in sign propagation, so a formatter that drops the sign changes results without changing any comparison.

File: CSV · Numeric Edges · 9 rows
Use case: Scientific dataCSV parsing+1· Conversion set

Binary versus Decimal Arithmetic — Where Floats Disagree (.csv)

Eight arithmetic expressions where binary floating point and exact decimal disagree, with both answers and the signed error side by side. Adding one cent a hundred times does not give one, and this file says by exactly how much.

File: CSV · Numeric Edges · 8 rows
Use case: Scientific dataCSV parsing+1· Conversion set

Catastrophic Cancellation — Naive versus Stable Formulas (.csv)

Five computations done twice, once with the obvious formula and once with the numerically stable one, with the relative error of the naive version alongside. The one-pass variance row is the memorable one: five values a millisecond apart near 1e8 can produce a negative variance.

File: CSV · Numeric Edges · 5 rows
Use case: Scientific dataCSV parsing+1· Conversion set

Shortest Round-Trip Float Representation — 15 vs 16 vs 17 Digits (.csv)

Twelve doubles printed at 15, 16 and 17 significant digits alongside their shortest round-tripping form, with a column recording which precisions actually recover the original bits. Fifteen digits is the default in a lot of formatting code and it loses values, which this table demonstrates rather than asserts.

File: CSV · Numeric Edges · 12 rows
Use case: Scientific dataCSV parsing+1· Conversion set

Floating-Point Summation — Five Orders, Five Answers (.csv)

The same 1002 numbers added five different ways, giving results from 0 to 1000 for an exact answer of 1000. Floating-point addition is not associative, and this file is the smallest complete demonstration of what that costs a naive accumulator.

File: CSV · Numeric Edges
Use case: Scientific dataCSV parsing+1· Conversion set

Spectrometer Absorbance With Expanded Uncertainty (.csv)

A synthetic absorbance scan from 400 to 630 nm with a Gaussian band at 520 nm, carrying its expanded uncertainty at k=2 in a dedicated column and a per-row quality flag. The unit and the coverage factor live in the column names, which is the convention most instrument exports actually use.

File: CSV · Measurements · 24 rows
Use case: Scientific dataCSV parsing+1· Conversion set

Units on a Second Header Row — Not Data (.csv)

The same instrument export with units on a second header row instead of inside the column names, which is how a great many laboratory instruments write CSV. An importer that treats row two as data types every measurement column as text and then quietly refuses to plot anything.

File: CSV · Measurements
Use case: Scientific dataCSV parsing+2· Conversion set

Thermocouple Time Series With Standard Uncertainty (.csv)

A full day of thermocouple readings at 30-minute cadence with a constant type-B standard uncertainty and two rows flagged as recovering. The timestamps are explicit UTC with a Z suffix so a reader has no excuse to guess a timezone.

File: CSV · Measurements · 48 rows
Use case: Scientific dataCSV parsing+2· Conversion set

Calibration Certificate — Error and Expanded Uncertainty (.csv)

Five calibration points with the nominal value, the measured value, the signed error and the expanded uncertainty at k=2 with its confidence level stated. It is a synthetic illustration of the layout, not an accredited certificate, and nothing in it refers to a real instrument or laboratory.

File: CSV · Measurements · 5 rows
Use case: Scientific dataCSV parsing+1· Conversion set

Titration Replicates — Mean, SD, SEM and RSD (.csv)

Four batches of five replicate titrations with the mean, sample standard deviation, standard error and relative standard deviation computed for each. The standard deviation uses the n-1 denominator, which is stated explicitly because a population-denominator implementation disagrees on every row.

File: CSV · Measurements
Use case: Scientific dataCSV parsing+1· Conversion set

GUM-Style Uncertainty Budget — Sources Combined in Quadrature (.csv)

A five-source uncertainty budget laid out the way the GUM prescribes: each source with its distribution, its divisor, its sensitivity coefficient and its contribution, then the combined and expanded values. Rectangular sources are divided by the square root of three, which is the step budget spreadsheets most often get wrong.

File: CSV · Measurements
Use case: Scientific dataCSV parsing+1· Conversion set

Significant Figures Lost to Float Parsing (.csv)

Eight written measurements where the trailing zeros carry the precision of the measurement, alongside what a float parse leaves behind. Parsing 1.200 to the double 1.2 is not a rounding error, it is the loss of the claim that the value is known to four figures.

File: CSV · Measurements · 8 rows
Use case: Scientific dataCSV parsing+1· Conversion set

Censored Values and Detection Limits — Non-Numeric Results (.csv)

Nine laboratory results where only four are plain numbers: two are below the detection limit, one is above range, two are missing in different spellings, and one is a legitimate small negative near the blank. Coercing the censored strings to numbers or to NaN both bias the summary, and the file distinguishes every case explicitly.

File: CSV · Measurements · 9 rows
Use case: Scientific dataCSV parsing+2· Conversion set

Interlaboratory Comparison — z-Scores and En Numbers (.csv)

Six fictional laboratories reporting the same measurand, scored both by z-score against a fixed sigma and by En number against each lab's own claimed uncertainty. The two statistics disagree about which labs are acceptable, which is the point: En rewards an honest uncertainty claim and z does not.

File: CSV · Measurements
Use case: Scientific dataCSV parsing+1· Conversion set

Convert v2 HDF5 Dataset Summary CSV

CSV reference listing the four expected HDF5 datasets with shapes and units for lightweight converter assertions. Stable P8 artifact p8-convert-hdf5-summary-csv.

File: CSV · P8 Convert · 4 rows
Use case: Conversion testingScientific data+1· Conversion set