Image Compressor
Drop in one or more images, adjust quality, and download the smaller versions. Nothing is uploaded: your photos are processed by your own browser.
Drop images here or click to choose files
JPG, PNG, WebP, GIF (first frame) · multiple files supported
Choosing a format
| Format | Best for | Notes |
|---|---|---|
| WebP | Almost everything on the web | Typically 25–35% smaller than JPEG at the same visual quality; supports transparency and is supported by every current browser. |
| JPEG | Photographs, maximum compatibility | Lossy, no transparency. Still the safest choice for email attachments and older software. |
| PNG | Screenshots, logos, line art, transparency | Lossless — re-encoding will not shrink a photo much, but it is ideal for flat graphics. |
What the quality slider does
For JPEG and WebP, quality controls how aggressively fine detail is discarded. In practice:
- 90–100 — visually lossless, but files stay large. Only worth it for print or further editing.
- 75–85 — the sweet spot for web images. Differences are invisible at normal viewing size.
- 50–70 — noticeable softening in flat areas and around sharp edges; acceptable for thumbnails.
- Below 50 — visible blocking artefacts. Useful only when size matters far more than fidelity.
Resizing beats compressing
The single biggest win is usually dimensional, not quality-based. A 4,000-pixel-wide photo displayed in a 800-pixel column carries 25× more pixels than it needs. Set a max width close to the largest size the image will actually be displayed at, then compress — the combination routinely cuts a 5 MB photo to under 150 KB.
Why smaller images matter
Images are typically the heaviest part of a web page, and Largest Contentful Paint — one of Google's Core Web Vitals — is usually determined by the main image. Faster images mean better rankings, lower bounce rates and less mobile data burned by your visitors.
What compression cannot undo
Lossy compression is one-way. Re-saving an already-compressed JPEG at high quality does not restore the lost detail; it just adds a second generation of artefacts. Always compress from the original whenever you can.
Frequently asked questions
Are my images uploaded to a server?
No. The file is read with the FileReader API, drawn to a canvas and re-encoded by your browser. There is no upload, no queue and no stored copy — you can verify by going offline after the page loads.
How much smaller will my image get?
Photographs typically drop 60–90% at quality 80, especially when converted to WebP. Screenshots and flat graphics compress less with lossy formats — PNG is often better for those.
Does compressing remove EXIF data?
Yes. Re-encoding through a canvas discards all metadata, including GPS coordinates, camera model and timestamps. That is a useful privacy side effect before sharing photos.
Is there a file size or count limit?
Only your device’s memory. Very large images (above roughly 50 megapixels) may fail on mobile browsers, which cap canvas dimensions.
Why did my PNG get bigger?
PNG is lossless, so re-encoding an already-optimised PNG can add bytes. For photographs choose WebP or JPEG; keep PNG only when you need transparency or crisp flat colour.
Does it work on my phone?
Yes. The tool is a single page with no dependencies and works in any modern mobile browser, including offline once loaded.