Compress images
Shrink JPEG, PNG and WebP files up to 80% smaller — right here in your browser. Your images are never uploaded.
Drop images here or click to choose
JPEG · PNG · WebP — compressed on your device, never uploaded
How it works
- Drop your images into the box above, or click it to pick files.
- Choose an output format and quality — the defaults work well for photos.
- Download each compressed image. Nothing is stored anywhere.
Why compress in the browser?
Most online image compressors upload your files to their servers, process them there, and send the result back. That means waiting on two transfers — and trusting a stranger's server with your photos.
shrink.run works differently: the compression engine (WebAssembly builds of MozJPEG, OxiPNG and libwebp) downloads to your browser once and runs locally. That makes it faster for large files, keeps working offline, and means there is no server that could log, keep or leak your images.
| Typical online tool | shrink.run | |
|---|---|---|
| Files uploaded | Yes, to their servers | Never |
| File size limits | Often 5–25 MB free | None |
| Batch limits | Often 2–20 files free | None |
| Works offline | No | Yes, after first load |
Frequently asked questions
Are my images uploaded to a server?
No. Compression happens entirely in your browser using WebAssembly builds of MozJPEG, OxiPNG and libwebp — the same codecs professional tools use. Your images never leave your device, and the site works even if you go offline after loading it.
Which formats are supported?
You can compress JPEG, PNG and WebP images, and convert between them. Choose "Same as input" to keep the original format, or pick JPEG or WebP for the smallest files.
What quality setting should I use?
For photos, a quality of 70–80 is usually indistinguishable from the original while cutting file size by 60–80%. For images with text or sharp edges, try 85–90. PNG output is lossless — pixels are never altered, only the encoding is optimised.
Is there a file size or count limit?
There is no artificial limit. Because processing happens on your own device, the practical limit is your browser memory — batches of dozens of photos work fine on a typical laptop or phone.
Does compressing images reduce their dimensions?
No — this tool keeps the original width and height and only re-encodes the pixels more efficiently. If you want smaller dimensions too, use our resize image tool.
Is this really free?
Yes. Because your device does the work, running this site costs almost nothing, and it is supported by ads instead of subscriptions or upload limits.