An image compressor that runs in your browser
Large images are the most common reason web pages load slowly. This image compressor re-encodes JPG, PNG and WEBP files with the quality you choose, optionally scales them down, and shows the saving for every file. Because the work happens in your browser with the Canvas API, there is no upload queue, no file-size cap and no waiting for a server.
How compression works
JPG and WEBP are lossy formats: the encoder discards detail the eye is unlikely to notice, and the quality setting controls how aggressively it does so. Going from 100% to 80% often halves the file size with no visible change, while below about 60% blocky artefacts and colour banding start to appear. PNG is lossless, so the quality slider has no effect on it; the tool therefore converts PNG to WEBP by default, which keeps transparency and is usually much smaller.
Options explained
- Quality (5–100%): applies to JPG and WEBP output. The preview updates a moment after you release the slider.
- Output format: "Same as input" keeps JPGs as JPG and turns PNG into WEBP; you can also force JPG, WEBP or lossless PNG. Transparent areas become white when saving as JPG.
- Max width: scales wider images down proportionally. A 4000-pixel phone photo shown at 1200 pixels wastes most of its bytes, so resizing is often the biggest saving of all.
Before/after comparison
The preview overlays the original and the compressed image. Drag across it (or use the arrow keys when it has focus) to move the divider and check faces, text and gradients — the areas where compression shows first. The statistics panel lists original and new size, dimensions, format and the percentage saved; if the result is larger than the original, you get a hint to lower the quality or choose another format.
Recommended settings
| Image | Format | Quality |
|---|---|---|
| Photos for blogs and shops | WEBP or JPG | 70–82% |
| Hero images | WEBP | 75–85%, max width 1920–2400 |
| Screenshots with text | PNG or WEBP | 90%+ (or lossless PNG) |
| Thumbnails | WEBP | 60–75%, max width 400–600 |
Batch compression
Add as many images as you like; each gets its own row with the saving. Changing a setting recompresses the whole batch, and Download all (.zip) packs the results into a single archive with "-compressed" file names. Note that re-encoding through the canvas also removes EXIF metadata such as camera details and GPS location — a privacy bonus for images you publish. If you want to keep the pixels untouched and only strip metadata, use the EXIF remover instead.
Need exact dimensions rather than a maximum width? Use the image resizer. To convert formats without compressing, see PNG to WEBP or JPG to WEBP.
Why image size matters
Images typically make up the largest share of a web page's bytes. Heavy images delay Largest Contentful Paint, one of Google's Core Web Vitals, cost mobile visitors data and slow down e-mail delivery when attached. Compressing before upload is also kinder to content management systems, many of which keep the original file forever even when they generate smaller variants.
Privacy
Everything happens locally in your browser with JavaScript and the Canvas API. Your images are never uploaded to our servers, so the tool also works with confidential screenshots and personal photos.