Add your PBM file
Drop one or more .pbm 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 .pbm 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 .pbm image to .apng re-encodes the pixels for a different balance of size, quality, and support. A .pbm file is a Portable Bitmap: the simplest image format in common use, storing exactly one bit per pixel — black or white, with no grey and no colour. It carries a two-character magic number, the width and height, and then the pixels, and nothing else.
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 .pbm, one bit per pixel — no grey, no colour, no transparency. 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 | Portable bitmap (.pbm) | Animated PNG (.apng) |
|---|---|---|
| Format type | Lossless — every pixel or sample is preserved exactly | Lossless — every pixel or sample is preserved exactly |
| How it stores data | two encodings share the extension: P1 stores pixels as ASCII 0 and 1 characters, P4 packs eight pixels into each byte | adds three chunk types to PNG: acTL (animation control), fcTL (frame control), and fdAT (frame data) |
| Strongest at | masks, stencils and other genuinely two-tone raster data | animated stickers (Apple's iMessage and LINE both build on APNG) |
| Weak spot | one bit per pixel — no grey, no colour, no transparency | files grow quickly for long or high-motion animations, where animated WebP/AVIF or video compress far better |
Drop one or more .pbm 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.
Since pbm is lossless-oriented and apng is lossless-oriented, the conversion preserves the source content exactly as stored; no additional compression pass is applied beyond what .apng itself requires.
Yes — the .pbm 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.
It depends on the content: adds three chunk types to PNG: acTL (animation control), fcTL (frame control), and fdAT (frame data). Convert one representative file first and compare before batch-processing a large set.
In .pbm, none beyond optional # comments in the header. There is no colour profile, no EXIF and no timestamp; a PBM carries dimensions and pixels and nothing else. 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.
Yes — the reverse route exists as a separate tool. Bear in mind that round-tripping .pbm → .apng → .pbm is not a perfect undo when any lossy step is involved; keep your original if fidelity matters.