Compress an image — in your browser
Pick your photos, set a quality or a target size in KB and download the result — single files or a ZIP for batches. Compression runs entirely in your browser using WebAssembly codecs (MozJPEG, WebP, OxiPNG): your images are never uploaded, and you see the before/after size down to the byte.
Quality or target size — which should I use?
The quality slider is right when you want to control how the image looks: 80 is a good default for photos. The target size in KB is right when a form or portal enforces a hard limit: the tool binary-searches for the highest quality that still fits under your limit — with at most 8 encoding passes. If the target is physically impossible for that image, you get an honest message with the smallest size reached instead of a silent overshoot.
Why WebP is often the better choice
According to Google's WebP compression study, WebP files are 25–34% smaller than JPEGs at equivalent visual quality. The catch with other tools: Safari can display WebP but cannot create it. This tool ships its own WebP encoder — WebP export works in Safari too.
Honest limits
- PNG is lossless: the quality slider only affects JPG/WebP; PNGs are re-optimised losslessly with OxiPNG, so savings are smaller there.
- Not every image shrinks: files that are already heavily compressed can even grow on re-encoding. The tool warns you instead of celebrating a worse result.
- EXIF is dropped: re-encoding removes metadata (GPS position, camera details) — usually a privacy win, but keep the original for your photo archive.