Image Compressor
Upload an image and adjust the quality slider to shrink its file size before downloading. Everything happens locally in your browser using the canvas re-encode the image.
How to use
- 1
Choose an image
Select a JPEG, PNG, or other image file from your device.
- 2
Adjust the quality slider
Drag to find the balance between file size and visual quality that works for you.
- 3
Compare before and after
Both versions and their file sizes are shown side by side.
- 4
Download the result
Click Download to save the compressed JPEG.
Examples
- A 4 MB photo at 70% quality → often shrinks to under 500 KB with little visible difference
- Dragging the slider down updates the compressed preview and size instantly
Frequently asked questions
Is my image uploaded to a server?
No. The image is read and re-encoded entirely in your browser using the HTML canvas API. It never leaves your device.
What file format is the compressed image?
The output is always a JPEG, since it compresses well and the quality slider directly controls JPEG's compression level. If you upload a PNG with transparency, the transparent areas will be filled in (typically white) in the JPEG output.
What quality setting should I use?
70-85% usually gives a good balance of small file size and minimal visible quality loss. Lower it further for thumbnails or previews where sharpness matters less.
Why didn't the file size shrink much?
If your original was already a compressed JPEG at a similar quality, or the image has little detail to compress, the size reduction may be small. Try a lower quality setting for a bigger reduction.