What is AVIF and why use it?

AVIF (AV1 Image File Format) is a modern royalty-free image format derived from the AV1 video codec. It produces dramatically smaller files than JPEG, PNG or animated GIF — often 40-70% smaller for the same perceived quality — while supporting transparency and animation.

Which browsers can display animated AVIF?

Chrome, Edge and Firefox all support animated AVIF, and Safari has it from version 16. For older browsers, supply an animated WebP or GIF fallback in your <picture> markup.

Is AVIF output from ffmpeg.wasm reliable?

AVIF encoding requires libaom-av1, which is included in the standard ffmpeg.wasm build. Animated AVIF support is solid but AV1 encoding is computationally heavy — expect significantly longer encode times than GIF or WebP.

How long does an AVIF encode take?

For 30 frames at 640px width, expect 20-60 seconds on a modern laptop. AV1 is notoriously slow to encode — that is the trade-off for its excellent compression efficiency.

How do I order the frames?

Select all frames at once — most browsers respect the alphabetical order of the filenames. Naming files frame-001.png, frame-002.png and so on guarantees the expected playback sequence.

Are my images uploaded?

No. ffmpeg.wasm runs entirely locally via WebAssembly. Your images never leave your device.

Animated AVIF Maker

Combine a sequence of images into an animated AVIF (.avif) — set frame delay, output width and loop count.

100% client-side · no upload

Note: AV1 encoding is slow — expect significantly longer waits than GIF or WebP, especially for 30+ frames.

Image frames (JPG, PNG, WebP) — in order Tip: name files frame-001.png, frame-002.png … so the picker keeps order.

Frame delay (ms) Width (px) Loop

Pick 2 or more images to begin.

How to build an animated AVIF

Pick all frames in playback order. JPG, PNG and WebP all work as input.
Set the frame delay (100 ms ≈ 10 fps; 40 ms ≈ 25 fps).
Choose an output width — 640px is a good default; larger sizes increase encode time considerably.
Press Build AVIF and wait. AV1 encoding is slow but produces tiny files.

Common use cases

Web performance: Replace heavy GIFs with AVIF for dramatically smaller page payloads.
Photo bursts: Stitch a 5-shot burst into a smooth, tiny animation for portfolio pages.
Product demos: Show a feature reveal with a clean AVIF instead of a multi-MB GIF.
Email-safe animations: Many modern email clients now render AVIF natively.

よくある質問

What is AVIF and why use it?: AVIF (AV1 Image File Format) is a modern royalty-free image format derived from the AV1 video codec. It produces dramatically smaller files than JPEG, PNG or animated GIF — often 40-70% smaller for the same perceived quality — while supporting transparency and animation.
Which browsers can display animated AVIF?: Chrome, Edge and Firefox all support animated AVIF, and Safari has it from version 16. For older browsers, supply an animated WebP or GIF fallback in your <picture> markup.
Is AVIF output from ffmpeg.wasm reliable?: AVIF encoding requires libaom-av1, which is included in the standard ffmpeg.wasm build. Animated AVIF support is solid but AV1 encoding is computationally heavy — expect significantly longer encode times than GIF or WebP.
How long does an AVIF encode take?: For 30 frames at 640px width, expect 20-60 seconds on a modern laptop. AV1 is notoriously slow to encode — that is the trade-off for its excellent compression efficiency.
How do I order the frames?: Select all frames at once — most browsers respect the alphabetical order of the filenames. Naming files frame-001.png, frame-002.png and so on guarantees the expected playback sequence.
Are my images uploaded?: No. ffmpeg.wasm runs entirely locally via WebAssembly. Your images never leave your device.

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