Image Compressor
Shrink and convert JPEG, PNG and WebP without uploading.
Quality has no effect on PNG, which is lossless — resizing or converting to WebP is what shrinks a PNG. Changing any setting re-processes the images already loaded.
How this compressor works
Each image is decoded, drawn onto a canvas at the size you choose, and re-encoded by the browser's own image encoder at the quality you set. Because that entire pipeline exists inside the browser already, no upload is needed — the files never leave your machine, there is no queue, and there is no limit on how many you process.
That last point is the practical difference from most compression sites, which cap you at ten files or 5 MB and hold your photos on a server for some period afterwards. Here the work is done by your own CPU.
Choosing quality and format
- 80% quality is the sweet spot for photographs. The difference from the original is invisible at normal viewing size while the file is typically a quarter of the size.
- 60–70% is fine for thumbnails, email attachments and anything shown small.
- WebP is roughly 25–35% smaller than JPEG at matching quality and is supported by every current browser. Convert to it unless you need to hand the file to something old.
- PNG is lossless, so the quality slider does nothing. Use it only for screenshots, logos and images that need transparency; converting a photograph to PNG makes it larger, not smaller.
- Resizing saves more than any quality setting. A 4000-pixel-wide photo displayed in a 800-pixel column is carrying sixteen times more pixels than it needs.
How to use it
- Drop in one image or a hundred.
- Set the quality, and pick a maximum dimension if the originals are larger than they need to be.
- Compare the before and after sizes for each file, and preview the result to check it still looks right.
- Download files individually, or use Download all.
Frequently asked questions
Are my photos uploaded?
No. Everything happens in your browser using the Canvas API. Nothing is transmitted, which is the reason this is safe for personal photographs, screenshots containing customer data or anything else you would not hand to a stranger's server.
Does compressing remove EXIF data?
Yes, and that is usually a benefit. Re-encoding through a canvas drops all metadata, including GPS coordinates, camera serial numbers and timestamps — worth knowing before publishing photos online. If you need EXIF preserved, this is the wrong tool.
Why did my PNG get bigger?
Because PNG is lossless and the browser's encoder does not apply the aggressive palette optimisation that dedicated tools like pngquant do. For a screenshot or a logo, converting to WebP will almost always produce a much smaller file at identical visual quality.
Can I compress a file that is already compressed?
You can, but each JPEG round trip discards a little more detail permanently — generation loss. Always start from the original file rather than re-compressing an already-compressed copy.
Is there a file size or count limit?
Only your device's memory. Very large images — 50 megapixels and up — take a moment to decode, and processing a hundred at once will make the browser work, but nothing is artificially capped.