Add your APNG file
Drop one or more .apng files onto the converter above, or browse for them. They load into browser memory only — nothing is uploaded, so there is no size-based pricing and no server queue.
Converting a .apng image to .webm re-encodes the pixels for a different balance of size, quality, and support. Free, private, and validated — the file never leaves your browser.
Batch files can each use a different output. Nothing uploads for local conversions.
Working inputs include camera RAW, browser-local audio/video, PDF, CBZ/CBR comics, office documents, ebooks, markup, 3D models, structured text, images, and archives.Converting a .apng image to .webm re-encodes the pixels for a different balance of size, quality, and support. An .apng file is an animated extension of PNG: full 24-bit color with 8-bit alpha per frame, in a stream that plain PNG decoders read as a normal still image. It delivers the smooth, semi-transparent animation that GIF's 256-color palette never could, and it is the format behind many messaging-app sticker packs.
A .webm file is an open, royalty-free video container built specifically for the web. It restricts itself to free codecs, VP8, VP9, or AV1 for video with Vorbis or Opus for audio, so any browser can play a .webm without patent licensing concerns. For this route the practical draw is free of patent royalties end to end and vP9 and AV1 deliver excellent compression efficiency — balanced against older iPhones and legacy Safari versions cannot play it, which is worth knowing before you commit a large batch.
Animated PNG keeps sharper edges than GIF but still struggles in players and social apps. Transcoding the full animation to WebM via the local FFmpeg engine yields a modern video container without collapsing the file to its first frame the way still-image pipelines would.
| Aspect | Animated PNG (.apng) | WebM video (.webm) |
|---|---|---|
| Format type | Lossless — every pixel or sample is preserved exactly | Container — quality depends on the codecs and settings inside |
| How it stores data | adds three chunk types to PNG: acTL (animation control), fcTL (frame control), and fdAT (frame data) | structured as a deliberately restricted subset of Matroska's EBML layout |
| Strongest at | animated stickers (Apple's iMessage and LINE both build on APNG) | serving HTML5 video without codec license fees |
| Weak spot | files grow quickly for long or high-motion animations, where animated WebP/AVIF or video compress far better | older iPhones and legacy Safari versions cannot play it |
Drop one or more .apng files onto the converter above, or browse for them. They load into browser memory only — nothing is uploaded, so there is no size-based pricing and no server queue.
Select .webm in the output menu next to each file. The menu only offers targets this engine can genuinely produce, so if WEBM is selectable, the route is real and validated.
Press Convert. Decoding and re-encoding happen on your device using the browser's native image pipeline and hand-tuned encoders.
Each result is signature-checked before the download unlocks, so a failed encode can never masquerade as a valid WEBM file. Outputs keep the original filename with the .webm extension.
Since apng is lossless-oriented and webm is container-oriented, the conversion preserves the source content exactly as stored; no additional compression pass is applied beyond what .webm itself requires.
Yes — the .apng file is processed inside your browser tab and never uploaded. Decoding and re-encoding happen on your device using the browser's native image pipeline and hand-tuned encoders. Close the tab and the file is gone from memory.
Chrome, Firefox, and Edge have played WebM for over a decade, and Safari added playback in 2021 starting with version 14.1 on macOS, with iOS following in iOS 15. Beyond browsers the picture thins out quickly, since many televisions, set-top boxes, and editors still expect MP4.
It depends on the content: structured as a deliberately restricted subset of Matroska's EBML layout. Convert one representative file first and compare before batch-processing a large set.