Image converter and compressor
PNG, JPEG, WebP or AVIF. Resize, compress, download. Nothing is uploaded.
How to convert and compress images
Add images
Choose files or drop them on the box, as many as you like. Conversion starts straight away, three files at a time, and each row shows a preview, the original size and the result.
Set the output
Pick the format, move the quality slider and set a maximum side in pixels if you want smaller dimensions. Any change re-converts every file, and the status line shows the total before and after.
Download
Use the button on a row for one file, or Download all to get a zip once more than one file is done. Files keep their names with the new extension.
Good to know
- Max side limits the longer edge and keeps the aspect ratio. 0 keeps the original size, and images smaller than the limit are never enlarged.
- Conversion runs in web workers with OffscreenCanvas, so the page stays responsive while large photos are processed. SVG files are rasterised on the main thread at their declared size.
- Animated GIF and WebP files are converted as a still image of the first frame.
- Green output sizes are smaller than the original. Turning a small JPEG into PNG usually makes it larger, because PNG is lossless.
- The zip is built in the browser and stores the files without extra compression, since the images are already compressed.
- A file that fails to decode shows the reason on its row. HEIC and RAW files are the usual cause; export them as JPEG from your phone or camera software first.
Questions people ask
Are my photos uploaded?
No. Decoding, resizing and encoding happen in your browser using the canvas API. Nothing is sent to a server.
Which formats can I convert from and to?
Input is anything your browser can decode: PNG, JPEG, WebP, AVIF, GIF, BMP and SVG, plus HEIC only in browsers that decode it. Output is PNG, JPEG, WebP or AVIF; a format this browser cannot encode is greyed out.
Why is AVIF greyed out?
Your browser can decode AVIF but cannot encode it. Most Chromium-based browsers can write AVIF; Safari and Firefox generally cannot yet. Pick WebP for a similar saving that works everywhere.
What does the quality slider do?
It sets the lossy compression level for JPEG, WebP and AVIF. 75 to 85 is a good range for photos. PNG is lossless, so the slider has no effect on it. Moving the slider re-converts every file so the sizes stay accurate.
Does it keep transparency and metadata?
Transparency is kept in PNG, WebP and AVIF. JPEG has no alpha channel, so transparent areas are filled with white. The image is rendered upright and saved without EXIF data, so camera details and GPS location are removed.