ICO — Multi-Resolution App Icon
A Windows ICO containing four square sizes (16/32/48/64 px) of a simple app glyph — the classic favicon/desktop-icon container. Handy for testing icon extraction and multi-size rendering.
Specifications
- Format
- ICO
- Sizes
- 16, 32, 48, 64 px
- Mode
- RGBA
- Content
- flat plus glyph on a blue tile
What is a .ico file?
ICO is a Windows icon container that bundles multiple image sizes and bit depths in a single file so the system can pick the best resolution. Each entry is stored as a BMP-style bitmap or embedded PNG, commonly at sizes like 16, 32, and 48 pixels. It is the traditional format for application and website favicons.
How to use this file
Use an example ICO to test favicon and icon extraction, multi-resolution selection, and converters that build ICO files from PNG sources.
How to use this file for testing
“ICO — Multi-Resolution App Icon” is a deterministic Novus Examples fixture for Conversion testing. The same content exported across many formats and linked as a group, so you can convert one and diff against the expected twin.
Documented properties for this file: ICO. Compare results against paired or grouped companions on this page when present (clean↔damaged, searchable↔scanned, or format twins) so scores stay reproducible across runs.
Download the file once, keep the path stable in CI or local scripts, and treat the spec table as the contract: dimensions, seeds, field lists, and roles are intentional. Corrupt or invalid samples are labelled as such — expect parsers to fail loudly rather than silently accept them.
For image AI or enhancement tools, run the model or filter on this file and diff against the clean or ground-truth companion in the same group when available. Keep seeds and documented damage parameters in your evaluation notes so regressions are attributable.
Code examples
<img src="app-icon.ico" alt="Example image" width="640" loading="lazy">Related files
- apngAPNG — Animated SpinnerA 12-frame animated PNG (APNG) of a rotating arc — a lossless, alpha-capable alternative to animated GIF. Useful for testing APNG support, frame extraction, and GIF↔APNG conversion.

- pbmPBM — Netpbm Test Image (P4)A 256×256 fruit still-life image as binary Netpbm P4 (1-bit bitmap) — the minimal, header-plus-raw-pixels family used across Unix imaging tools. For testing Netpbm parsers and conversion.

- pgmPGM — Netpbm Test Image (P5)A 256×256 fruit still-life image as binary Netpbm P5 (8-bit greyscale) — the minimal, header-plus-raw-pixels family used across Unix imaging tools. For testing Netpbm parsers and conversion.

- ppmPPM — Netpbm Test Image (P6)A 256×256 fruit still-life image as binary Netpbm P6 (24-bit colour) — the minimal, header-plus-raw-pixels family used across Unix imaging tools. For testing Netpbm parsers and conversion.

- tgaTGA — Truevision Test ImageA 256×256 fruit still-life image saved as uncompressed Truevision TGA — a format common in games and 3D texturing. For testing TGA decoders and conversion to modern formats.

- png16-bit Grayscale PNG (deep colour)A 16-bit (deep-colour) grayscale PNG holding a smooth 0–65535 gradient — for testing high-bit-depth support and spotting banding when a tool truncates to 8-bit.

Generated by generation/images_formats2.py. Free for any use, no attribution required — license.