Why compress JPEGs in the browser?
JPEG is the default output for every phone, mirrorless camera, and screenshot tool on the web. The format is already lossy, but most cameras and software export at quality 90+ with extra metadata (EXIF, XMP, ICC profiles) that bloats files by 20–100 KB each. Re-encoding with a modern encoder like mozjpeg removes that overhead and uses better quantization tables, so the same visible quality needs fewer bytes.
Pixshrink runs mozjpeg as WebAssembly directly in your tab. The file you select never leaves your device — no upload, no server queue, no signup wall. You can compress a folder of wedding photos on a flight, or shrink 200 product shots for Shopify, and nothing is logged anywhere.
What size reduction should I expect?
Results depend on the source, but on a typical 4032×3024 phone photo at original quality 95, the mozjpeg pipeline at quality 75 produces a file 80–90% smaller with no visible difference in side-by-side viewing. If you push to quality 60, you can hit 95% reduction; below that, JPEG's 8×8 DCT blocks start to show as ringing around high-contrast edges.
The slider is the main control. A few practical rules of thumb: quality 80 is the sweet spot for hero photos on a website; quality 70 is fine for product thumbnails and avatars; quality 50 works for preview images that load before a higher-res version.
What about EXIF and metadata?
By default Pixshrink strips EXIF (camera, GPS, timestamps) from JPEGs. That alone usually saves 30–80 KB and removes the privacy side-effect of shipping a photo with your home address baked into the file. You can re-enable metadata preservation from the options panel if you need it for archival work.
Also try the other formats
If you want the smallest possible file at the same visual quality, re-encoding to WebP or AVIF usually beats JPEG by another 20–40%. For screenshots and UI captures with sharp text and flat colors, PNG is often already optimal and can be losslessly shrunk with oxipng. For animations, see GIF compression.