Compress images
Shrink JPEG, PNG and WebP files right here in your browser, and see compare the file size and quality before you download. Your images are never uploaded.
Drop images here or click to choose
JPEG · PNG · WebP — compressed on your device, never uploaded
Comparing
Drag the handle — or focus it and use the arrow keys — to compare. Moving the quality slider re-compresses this image live.
PNG output is lossless — the quality slider does not apply to it.
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. The selected files are not sent to us.
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, 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 from us; bounded by your device's memory |
| Batch limits | Often 2–20 files free | None from us; bounded by your device's memory |
| Upload connection while it works | Required | Not required |
Frequently asked questions
Are my images uploaded to a server?
No. Compression happens in your browser using WebAssembly builds of MozJPEG, OxiPNG and libwebp. The page and codec files use normal network requests, but the images you select are not included in them.
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, start around 75–80 and inspect the preview before downloading. Images with text or sharp edges may need a higher setting. PNG output is lossless — pixels are not 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.