Compress images
The same encoders the well-known compression services run on their servers — except here they run on your machine, so your photographs never leave it.
- Runs entirely in your browser
- Works offline
- No upload
- No sign-up
- No watermark
Loading the tool…
How it works
- Drop your images.
- Set the quality; “Compress harder” switches to MozJPEG / OxiPNG.
- Compress and download, individually or as a ZIP.
Why nothing is uploaded
Every operation on this page is done by code running inside your browser tab, using the same engine that renders web pages. The file is read from disk into your tab’s memory, transformed there, and written back out as a download. It is never sent anywhere — not to us, not to a third party.
Verify it yourself
- Open your browser’s developer tools (F12) and select the Network tab.
- Load your file and run the tool.
- The only requests you will see fetch the tool’s own code — and, for a few heavy tools, their open-source engine from a public CDN — plus one small page-view ping to loreatec.jp (page address and title, nothing more). None of them carry your file.
Frequently asked questions
What does “squeeze harder” actually change?
For JPEG it swaps your browser’s built-in compressor for a stronger open-source encoder, which packs the data more cleverly and typically saves another 10–20% at the same visual quality. For PNG it runs a lossless optimiser, which loses nothing: it only repacks the data, so every pixel comes out exactly the same.
Does PNG compression lose quality here?
No. The PNG optimiser never changes a pixel. If you need a big reduction on a photograph stored as PNG, convert it to JPG or WebP instead — that is where the real saving is.
The saving is 0%. Is it broken?
No. Some files are already optimally packed, usually because they came out of another compressor. The tool reports the real number instead of quietly handing back a re-encoded file of the same size.
Are the images uploaded to convert them?
No. Your browser opens the image, redraws it and saves it in the new format, all on your device. Load the page, switch your connection off and the conversion still works — that is the proof.
Is there a size or batch limit?
None that we impose. Drop a hundred files if you like; they are processed one after another with a progress bar, and the only limit is your device’s memory.
What happens to the hidden photo data (EXIF, GPS location)?
It is removed by default, which is usually what you want before sending a photo to anyone. Tick “Keep EXIF” if you need the date and camera details kept in a JPEG output.