FreeNo uploadNo sign-upBatch
Image Compressor
Shrink JPG, PNG and WebP images while keeping their format. Nothing is uploaded.
Drop JPG, PNG or WebP images to compress
batch and mixed formats welcome
- Private by design. Converted inside your browser.
- Instant. No upload queue, no waiting.
- Unlimited. Convert hundreds of files, download as ZIP.
How to compress images
Add your images
Drop files on the tool, click Choose files or paste from the clipboard. Add as many as you like.
Set the quality
Move the quality slider. Lower means smaller files; the before and after sizes update instantly.
Download smaller files
Save each file or download everything as a ZIP. Files that cannot get smaller are returned unchanged.
Smaller images without visible loss
Large images slow down websites, bounce off email limits and fill up phone storage. Most photos carry far more data than the eye can see, so they can be made much smaller without a visible change.
This compressor keeps each image in its own format. JPG and WebP are re-encoded at the quality you choose; PNG is reduced to an optimised colour palette, the same technique popular PNG optimisers use. If a file would not get smaller, you get the original back.
Frequently asked questions
Does compressing change the image format?
No. JPG stays JPG, PNG stays PNG and WebP stays WebP. Other formats, such as HEIC, are saved as JPG.
How much smaller will my images be?
It depends on the image. Large photos often shrink by more than half; already optimised images may not shrink at all, and then the original is kept.
Will I see a quality loss?
At 75–85% quality the difference is very hard to see. Compare the before and after sizes and adjust the slider until you are happy.
Is there a file size limit?
There is no upload, so there is no server limit. Very large images depend on your device’s memory.
Are my files uploaded to a server?
No. formatmath converts files with code that runs inside your browser. Your files are never uploaded, stored or seen by us.
Is it free?
Yes. There is no watermark and no daily limit. An account is optional and only keeps a history of your conversions.