How this compressor works
Most online image compressors upload your files to a server, process them there, and send them back. This one uses the browser's own Canvas API, which means every file is decoded, resized, and re-encoded on your own machine. Nothing is transmitted, nothing is stored, and there is no queue to wait in.
Because the work happens locally, file size limits do not really apply — the practical ceiling is your device's available memory, not an upload cap. Large batches of high-resolution photos will simply take a little longer. Just need to change the format without touching quality? Try the Image Converter.
Choosing the right output format
- WebP — the best default for the web. Typically 25–35% smaller than JPG at the same visual quality, and supported by every modern browser.
- AVIF — smaller still, often 50% below JPG, but slower to encode and not supported in a few older browsers.
- JPG — the safe universal choice for photographs when compatibility matters more than file size.
- PNG — lossless, so quality settings have little effect. Use it only for logos, screenshots, and images that need transparency.
Picking a quality level
Quality maps to the encoder's compression setting, not to a fixed file size. For photographs, 75–85 is the range where most people cannot see the difference from the original. Below 60, artifacts start appearing around edges and in flat areas like skies. Above 90, file size grows quickly for gains almost nobody notices.
Screenshots and images containing text behave differently — they hold up better in PNG or at higher JPG quality, because sharp edges are exactly what lossy compression struggles with.
Resizing before compressing
The single biggest saving usually comes from dimensions, not quality. A 4000px-wide photo displayed in a 800px column is carrying about 25 times more pixel data than it needs. Set a max width that matches where the image will actually be shown, and the quality slider becomes a fine adjustment rather than a blunt instrument.
Frequently asked questions
Are my images uploaded anywhere?
No. Processing happens entirely in your browser using local JavaScript. You can verify this by opening your browser's network tab while compressing — no file data is sent.
Is there a file size or count limit?
There is no server-side limit. Very large batches or extremely high-resolution files may slow down depending on your device's memory.
Why did my PNG get bigger?
PNG is lossless. Converting a heavily compressed JPG into PNG re-encodes it without any lossy savings, which usually increases size. For photographs, choose WebP or JPG instead.
Does compressing remove EXIF data?
Yes. Re-encoding through the canvas strips metadata including camera details and GPS location — useful if you are sharing photos publicly.