Compress an image
Reduce an image file, and its dimensions if you need to
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JPG or PNG image · Up to 100 MB
How do you reduce the size of an image?
The tool rewrites the image at the quality you choose and, if you ask, shrinks its longest edge. The result is a JPG. Give it several images and they come back as one ZIP; the change in size is measured and shown every time.
What this tool does not do
- It never enlarges an image — it only reduces.
- It does not promise a smaller file every time: an already-compressed image rewritten at high quality can grow.
- It does not preserve transparency: the result is a JPG, so transparent areas are filled white.
Example: a whiteboard photo from a phone
A 4032×3024 phone photograph came to 3.8 MB. With medium quality and the large size selected, the image became 2000×1500 and 410 KB — roughly nine times smaller, with no visible difference on screen or printed on A4. The same photograph kept at its original dimensions still came to 1.6 MB: reducing the dimensions moves the file size far more than the quality setting does.
When an image goes with a paper
Journal portals and conference systems cap the size of an upload, and a photograph straight from a phone camera routinely exceeds it. Almost all of that size comes from the pixel count: for a figure placed on an A4 page, 4000 pixels of width is wasted and 2000 is enough even in print. So reduce the dimensions first and the quality second. Keep the original photograph in your archive — a rewritten image cannot be restored. Open the compressed image at full size and look at it: the small labels on charts and drawings are the first thing to become unreadable. Rather than compressing a screenshot of a graph, export it as an image straight from the program that drew it — Excel or Origin, say — which gives a file that is both smaller and sharper.
| Accepts | JPG or PNG image |
|---|---|
| Returns | Several files — in a ZIP archive |
| Maximum file size | up to 100 MB |
| Several files at once | Yes |
| Is the file uploaded | No — everything runs in your browser |
| Price | Free |
| Account needed? | To download — yes (free) |
Frequently asked questions
How much does quality suffer?
It depends on the level you pick. High is practically indistinguishable by eye; low reduces the file most and is noticeable on small text.
Why is the result always a JPG?
JPG gives the most effective compression for photographs. If you need a PNG, use the Convert JPG and PNG tool.
Can I process several images at once?
Yes. Several images come back as one ZIP, with the file names numbered in order.
What if the file does not get smaller?
You still get the result, but the size before and after is shown side by side — so you can decide which one you actually want.