When this tool is useful
Small interface demonstrations, stickers, diagrams, and short transparent animations that need full-color frames in software that supports APNG.
How local processing works
The browser decodes each static frame, fits it onto one bounded RGBA canvas, compresses PNG scanlines, and writes validated acTL, fcTL, IDAT, and fdAT chunks with deterministic sequence numbers and checksums.
How to use it
- Prepare and preserve the source: Keep the unchanged source, review the intended destination, and begin with conservative limits. Small interface demonstrations, stickers, diagrams, and short transparent animations that need full-color frames in software that supports APNG.
- Run the bounded local operation: Process only in this browser and stop on unsupported, malformed, or ambiguous input. The browser decodes each static frame, fits it onto one bounded RGBA canvas, compresses PNG scanlines, and writes validated acTL, fcTL, IDAT, and fdAT chunks with deterministic sequence numbers and checksums.
- Inspect the result: Reopen the APNG in two intended viewers, confirm frame order, canvas edges, transparency, delay, total duration and loop behavior, then keep every source frame until accepted.
Important limitations
All frames are flattened to one size. Source metadata and color profiles are not retained, compression can be large, and applications without APNG support may show only the first frame.
Verify the downloaded result
Reopen the APNG in two intended viewers, confirm frame order, canvas edges, transparency, delay, total duration and loop behavior, then keep every source frame until accepted.
Private by design
Your files stay in this browser. The tool does not upload the source or output to our servers.
Questions and answers
When is this tool useful?
Small interface demonstrations, stickers, diagrams, and short transparent animations that need full-color frames in software that supports APNG.
What does the local operation do?
The browser decodes each static frame, fits it onto one bounded RGBA canvas, compresses PNG scanlines, and writes validated acTL, fcTL, IDAT, and fdAT chunks with deterministic sequence numbers and checksums.
Which limitations matter?
All frames are flattened to one size. Source metadata and color profiles are not retained, compression can be large, and applications without APNG support may show only the first frame.
How should I verify the result?
Reopen the APNG in two intended viewers, confirm frame order, canvas edges, transparency, delay, total duration and loop behavior, then keep every source frame until accepted.