APNG: Animated Spinner
A 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.
Specifications
- Format
- APNG
- Width
- 128
- Height
- 128
- Frames
- 12
- Frame Duration Ms
- 90
- Loop
- infinite
- Alt Text
- A 12-frame animated PNG (APNG) of a rotating arc: a lossless, alpha-capable alternative to animated GIF
- Alt Text Source
- description
Testing contract
Expected to pass- Scenario
- Exercise APNG: Animated Spinner in its raster formats workflow. A 12-frame animated PNG (APNG) of a rotating arc: a lossless, alpha-capable alternative to animated GIF.
- Expected result
- Decoded geometry is 128×128 pixels in RGBA mode; frame count is 12. Declared feature checks: frames=12; frameDurationMs=90; loop=infinite.
What is a .apng file?
APNG (Animated PNG) extends the PNG format with animation by adding frame-control chunks while remaining backward compatible with static PNG decoders. It supports full 24-bit color and 8-bit alpha per frame, unlike GIF's 256-color limit. It is used for high-quality short animations.
How to use this file
Use an example APNG to test animated-PNG decoding, backward-compatible fallback to the first frame in older decoders, and conversion to and from GIF or WebP.
How to use this file for testing
“APNG: Animated Spinner” is a deterministic Testaroo 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: 128×128 · APNG. 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="spinner.apng" alt="Example image" width="640" loading="lazy">Generated by generation/images_formats2.py. Free for any use, no attribution required, license.
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