Add your JP2 file
Drop one or more .jp2 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 .jp2 image to .apng 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 .jp2 image to .apng re-encodes the pixels for a different balance of size, quality, and support. A .jp2 file is a JPEG 2000 image in the boxed JP2 container: wavelet-compressed raster data plus the header boxes that declare its colour space and metadata. It was designed as JPEG's technical successor and, although the web never adopted it, it became the standard in digital cinema, medical imaging, and archival scanning.
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. For this route the practical draw is 16.7 million colors and real alpha per frame, versus GIF's 256 and binary transparency and backward compatible: old decoders still render the first frame — balanced against files grow quickly for long or high-motion animations, where animated WebP/AVIF or video compress far better, which is worth knowing before you commit a large batch.
The practical trigger for this conversion is usually a mismatch: with .jp2, no mainstream browser decodes it, and Safari dropped its support, so it is unusable for web delivery. Switching to .apng buys you 16.7 million colors and real alpha per frame, versus GIF's 256 and binary transparency, which is why it is the better fit for animated stickers (Apple's iMessage and LINE both build on APNG). Because the conversion runs locally, trying it costs nothing but a few seconds of compute on your own machine.
| Aspect | JPEG 2000 image (.jp2) | Animated PNG (.apng) |
|---|---|---|
| Format type | Lossy — discards detail it judges invisible to shrink files | Lossless — every pixel or sample is preserved exactly |
| How it stores data | discrete wavelet transform: the reversible LeGall 5/3 filter for lossless coding and the irreversible CDF 9/7 filter for lossy | adds three chunk types to PNG: acTL (animation control), fcTL (frame control), and fdAT (frame data) |
| Strongest at | digital cinema packages, where the DCI specification mandates JPEG 2000 for the picture track | animated stickers (Apple's iMessage and LINE both build on APNG) |
| Weak spot | no mainstream browser decodes it, and Safari dropped its support, so it is unusable for web delivery | files grow quickly for long or high-motion animations, where animated WebP/AVIF or video compress far better |
Drop one or more .jp2 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 .apng in the output menu next to each file. The menu only offers targets this engine can genuinely produce, so if APNG 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 APNG file. Outputs keep the original filename with the .apng extension.
No new loss is introduced — since jp2 is lossy-oriented and apng is lossless-oriented, everything the .jp2 file still contains is carried over exactly. What was already discarded by the original lossy encode cannot be recovered, though; converting to .apng does not "restore" quality.
Yes — the .jp2 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 59+, Firefox 3+, Safari 8+, and Edge 79+ all animate .apng natively, so browser coverage is complete. Desktop support is patchier — most image editors open only the first frame — and social platforms frequently flatten or re-encode uploads, so test the target platform before committing to it.
Larger, sometimes much larger. A lossless .apng must store every pixel or sample the decoder produced, without the perceptual shortcuts .jp2 used. Use this route for editing headroom, not for saving space.
In .jp2, the JP2 container holds an ICC profile in its colour specification box and can carry XMP in a UUID box, EXIF in a UUID box, arbitrary XML, and an intellectual-property box. This converter reads the pixels only; header boxes are not carried into the raster outputs. Re-encoding through the browser pipeline does not carry embedded metadata into the output, which doubles as a privacy scrub — check the exported file if you specifically need tags preserved.