In-browser image optimizer
Compress a JPEG without uploading it
JPEG is the format that opens everywhere, but it is also the one most people never re-compress. Dropping a phone photo into Lighterpix and pulling the quality slider to 80 usually removes more than half the bytes with no visible difference at normal viewing size.
Compress a JPEG in three steps
- Open the JPEGDrop the file on the page, or choose it from the file picker. A 12-megapixel photo opens in a couple of seconds because the decoder runs locally.
- Compare JPEG against WebP and AVIFBoth panes are live. Keep MozJPEG on one side and swap the other to WebP or AVIF to see exactly what a modern codec buys you for this picture.
- Save the file you likeDownload the winning pane. Around 80–85 quality is a safe default for photographs; go lower for thumbnails and background images.
Why re-compress a JPEG at all?
Cameras and phones write JPEGs at a quality nobody sees on screen. Websites, email clients and chat apps then send those bytes again and again. Re-encoding at a sensible quality once is the cheapest performance win available: a 4 MB photo often lands under 400 KB.
MozJPEG, not a generic encoder
Lighterpix uses MozJPEG, the encoder Mozilla built for Firefox, plus the browser’s own JPEG encoder for reference. Progressive mode, optimised Huffman tables and trellis quantisation all help — you get the options without installing anything.
What to expect
| Quality | Looks like | Good for |
|---|---|---|
| 90–95 | Indistinguishable from the original | Print, archives |
| 80–85 | Safe for full-screen viewing | Photos on a website |
| 65–75 | Slight softening in fine detail | Cards, thumbnails, email |
| 40–60 | Visible artefacts | Placeholders, backgrounds |
Questions
Can I compress a JPEG without losing quality?
Not losslessly — JPEG has no lossless mode. But at quality 85 or above the difference is invisible at normal viewing size, while the file shrinks by half or more.
Does the EXIF data survive?
The encoder writes a fresh file, so metadata such as GPS coordinates and camera settings is not carried over. For photos you publish that is usually what you want.
Is there a file size limit?
The limit is your device’s memory rather than a server quota. Multi-megapixel photos and even large panoramas work; extremely large images are slower on phones.