Compress JPG photos in your browser — without uploading
Drop a JPG or JPEG photo and Tinier compresses it locally on your device using MozJPEG, the same engine Mozilla built to make Firefox's JPEG handling smaller and faster. Most photos come out 60–80% smaller at the default quality of 75, with no perceptible difference. Nothing uploads. No signup. No rate limit. Up to 50 MB per file, 1 to 10 files at a time.
How JPG compression actually works
JPG compresses by breaking the image into 8×8 pixel blocks and storing each one with just enough precision to look right to the human eye. The quality setting controls how much precision it keeps. MozJPEG, Mozilla's optimized JPEG encoder, is smarter than the default encoders about where to spend bits — it puts detail where your eye notices and saves it where you don't. That is why a MozJPEG file at quality 75 often looks as good as a stock file at quality 90, at a smaller size. It all runs in a Web Worker so your interface never freezes.
When to lower the quality slider
The default quality of 75 is the sweet spot for most photos — big savings, no visible loss. Drop it toward 50 when you need the smallest possible file and can accept mild softening visible only on close inspection, like a background image or a thumbnail. Push it toward 90 when the photo has fine detail you cannot afford to lose. The built-in before/after comparator shows you exactly what each setting costs, so you are never guessing.
Why compress JPG in the browser instead of on a server?
Most online JPG compressors upload your photo to a server, compress it there, and send it back. That round-trip adds time and puts your photo on someone else's hardware. Tinier compresses locally with MozJPEG compiled to WebAssembly, so your photo never leaves your device — you can disconnect your internet after the page loads and it keeps working. On photos under 10 MB it is also faster, because it skips the upload and download entirely.
Frequently asked questions about JPG compression
Is JPG compression lossy?
Yes. JPG is a lossy format by design — it discards some detail to save space. At the default quality of 75, the loss is imperceptible on photos. MozJPEG is unusually good at keeping perceived quality high while shrinking the file. If you need a pixel-perfect result, use PNG instead.
What is the difference between JPG and JPEG?
None. JPG and JPEG are the same format — the ".jpg" extension is a leftover from when Windows required three-letter file extensions. Tinier treats them identically.
Does Tinier remove EXIF data from my JPG?
Yes. Re-encoding through MozJPEG drops the EXIF metadata (camera model, GPS location, timestamps), which both shrinks the file and removes information you may not want to share. The visible image is unchanged.
How big can my JPG file be?
Up to 50 MB per file, 1 to 10 files at a time. That is the practical limit of browser memory, not a paywall. Larger files take more memory and may take longer depending on your device.
Other formats Tinier compresses
- Compress PNG — lossless optimization with OxiPNG, no quantization tricks.
- Compress WebP — Google's modern image format, in your browser.
- JPG to WebP — convert JPG to a smaller WebP for the web.
- Image compressors compared — an honest look at where Tinier wins and where it does not.