No server upload
Compress image
Phone photos often weigh 3–8 MB, although a website, email or messenger needs only a few hundred kilobytes. Compression runs on your device with Canvas: the image is not uploaded and is not stored anywhere outside your browser memory.
The image is processed in your browser and never uploaded.
How to compress an image
- 1Choose a photo or drop it into the window
- 2Move the quality slider and watch the result size
- 3Download the compressed file
How compression works
The browser decodes the image and re-encodes it at the selected quality and format. By default the format is kept: JPG stays JPG, PNG stays PNG, WebP stays WebP. Lower quality means a smaller file and more visible artefacts around edges, text and fine detail.
Quality 70–80% usually makes a photo 3–10 times smaller with no visible difference on screen. For previews and thumbnails, 50–60% is enough. For print and archiving, keep the original instead.
Transparency is kept in PNG and WebP. JPEG has none, so transparent areas turn white and the tool warns you about it. For PNG the size drops by reducing the number of colours, while transparent pixels stay transparent.
Frequently asked questions
Is the file uploaded to a server?
No. Compression runs in your browser with Canvas, so the image stays on your device. The server is used only for video and document converters.
How much smaller will the file get?
It depends on the source and the quality you pick. Phone photos usually get 3–10 times smaller at 70–80%. Screenshots and sharp graphics compress less.
What happens to transparency?
With the "Same as source" format, PNG and WebP keep transparency. Only if you pick JPEG do transparent areas turn white, and the tool warns you about it.
Which format gives the smallest file?
For photos WebP or JPEG works best. WebP is usually lighter at the same quality and keeps transparency. For logos and screenshots with transparency pick WebP or PNG.
Can I compress several photos at once?
Yes. Batch processing is available in the image converter: select several files and download the result as a single ZIP.