Image Compressor
Free image compressor. Shrink JPG and PNG photos by choosing quality from 10 to 90. Works fully in your browser. Private, fast, no signup needed.
About this tool
Huge photos slow down websites, clog inboxes and eat phone storage. An image compressor shrinks your pictures to a fraction of their size while keeping them looking great, by saving them as efficient JPEGs at a quality level you choose.
This free tool does all the work in your browser. Your photos are never uploaded to any server, so your files never leave your device. Pick a quality, click once, and download a much smaller file.
How to use
Choose any JPG, PNG or other common image from your device. Enter a quality number between 10 and 90: 70 to 80 is the sweet spot for web use, looking nearly identical to the original at a much smaller size. Lower numbers mean smaller files.
Click Compress Image and the tool shows the approximate new size before you download. Try 70 first; if the file is still too big, go lower, and if you spot artifacts, go higher.
The math behind it
JPEG compression works by throwing away fine visual detail the human eye barely notices, especially in smooth areas and subtle color shifts. The quality setting controls how aggressive this is: at 90 almost nothing is discarded, at 10 most detail is gone.
Because photos contain smooth gradients and natural noise, they compress beautifully. The tool redraws your image onto a canvas and re-encodes it as JPEG at your chosen quality, which is why a 4 MB phone photo can become a crisp 300 KB file.