Compress images online
Reduce the file size of JPG, PNG and WebP images without visibly losing quality. Compression runs entirely in your browser, so your photos are never uploaded anywhere.
100% private: files are processed in your browser and never uploaded to any server.
How it works
- Drop one or more images into the box above, or click to choose files.
- Pick a quality level, or type an exact target size in KB.
- Download each compressed image — the size saving is shown next to every file.
Good to know
File size comes from two things multiplied together: how many pixels there are, and how many bytes are spent on each. Most people only touch the second. If you need a big reduction, reducing the dimensions first and then compressing at a sane quality looks far better than crushing a 4000-pixel photo with the quality slider alone.
As a rule of thumb, JPEG quality below about 60% starts to be visible and below 40% is obvious. If you set a target size in KB, this tool searches for the highest quality that fits and only scales the image down when quality alone cannot get there.
PNG behaves differently: it is lossless, so it cannot discard detail to save space. A photographic PNG will barely shrink — convert it to JPG first if the destination allows it. Whatever happens, the result is never handed back larger than the file you started with.
Read more: How to compress an image to an exact size in KB · HEIC vs JPG: why your iPhone photos won't open · PNG vs JPG vs WebP: which one should you use? · Why in-browser image processing is more private
Frequently asked questions
Does compressing an image reduce its quality?
Lossy compression removes detail the eye barely notices. At the default setting the difference is invisible for most photos; if you need a smaller file you can lower the quality or set a target size and let the tool find the best balance.
Are my images uploaded to a server?
No. Imgnest compresses images with code that runs inside your browser. Your files never leave your device — you can even disconnect from the internet after the page loads and the tool keeps working.
Is there a limit on file size or number of images?
No. Because processing happens on your device, there are no queues, no daily limits and no maximum file size beyond what your browser can handle.
Which formats can I compress?
JPG/JPEG, PNG and WebP. If you need to shrink an iPhone photo, use the HEIC to JPG converter first, then compress the result.