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PocketConvert
  • HEIC to JPGiPhone photos that open anywhere
  • HEIC to PNGLossless copies of iPhone photos
  • JPG to WebPSmaller photos for faster websites
  • WebP to JPGOpen WebP images in any app
  • PNG to WebPKeep transparency, cut the file size
  • WebP to PNGA lossless copy with transparency
  • JPG to PNGA lossless copy for editing
  • PNG to JPGSmaller files for email and uploads
Convert a file

How it works

PocketConvert converts files with the same engine your browser uses to display them. Nothing is sent to a server, which makes it both faster and more private than upload-based converters.

Your browser does the work

When you add a file, it's read directly from your disk into this browser tab. Images are decoded by the browser's built-in image decoder, drawn onto a canvas, and encoded again in the format you chose. PDFs are assembled with a small PDF library that runs in the page.

All of this happens in a Web Worker, a background thread, so the page stays responsive even while large images are being processed.

Format details

  • JPG and WebP are encoded by your browser at the quality you pick. Safari can't write WebP natively, so on Safari a WebAssembly build of Google's libwebp is loaded the first time you need it.
  • PNG compression reduces an image to an optimised palette of up to 256 colours with dithering, then writes an indexed PNG. Transparency is kept.
  • JPG to PDF embeds your JPG data as it is, without re-compression. EXIF metadata is removed first.
  • HEIC photos open natively in Safari. Other browsers load a WebAssembly build of libheif the first time you convert one.
  • PDF to image renders pages with pdf.js, the engine behind Firefox's PDF viewer.
  • Audio and video are demuxed and muxed in JavaScript and decoded and encoded with your browser's WebCodecs, usually hardware-accelerated. Videos that are already H.264 are copied into MP4 without re-encoding. MP3 is encoded with a WebAssembly build of LAME.
  • Photos are always rotated upright according to their EXIF orientation, and metadata such as GPS location is not copied into converted images.

Limits

You can convert up to 25 files at a time. Images can be up to 50 MB each, PDFs 100 MB, audio 500 MB and video 1 GB. Files are processed one after another to keep memory use predictable on phones.

Safari on iPhone and iPad can't process images larger than about 16.7 megapixels. Larger photos are scaled down just enough to fit, and the result tells you when that happened.

Supported browsers

Current versions of Chrome, Edge, Firefox and Safari on desktop, Android and iOS. If a browser can't perform a particular conversion, you'll see a message saying so rather than a broken file.