Image Compressor

How image compression works

This tool re-encodes each image as a JPEG at the quality level you choose using the browser's canvas element. Lower quality settings throw away more visual detail in exchange for a smaller file drag the slider, compress, and check the before/after file size shown next to each image to find the right balance for your use case.

Lossy compression, in plain English

JPEG uses "lossy" compression, meaning some image data is permanently discarded to shrink the file unlike "lossless" formats like PNG, which shrink files without losing any pixel-level detail but can't compress photographic images nearly as much. For photos, lossy compression at a moderate quality setting (60-80%) is usually indistinguishable from the original to the eye while cutting file size dramatically. For flat graphics with sharp edges, like logos or screenshots with text, lossy compression can introduce visible blur or blocky artifacts around edges those often compress better with a lossless format instead.

Why smaller image files matter

Page load speed is one of the biggest factors in whether visitors stay on a website, and images are typically the heaviest part of any web page. A single uncompressed photo straight from a modern phone camera can run 4-8MB; compressed to 70% quality, the same photo often drops to under 500KB with little visible difference. That matters for search rankings too Google's Core Web Vitals directly measure how fast a page's main content loads, and oversized images are one of the most common causes of a slow score.

Will this affect transparent PNGs?

Yes since JPEG doesn't support transparency, any transparent areas in a PNG are filled with white before compression. If you need to preserve a transparent background, compressing to JPEG isn't the right tool; look for a PNG-specific compressor instead.

FAQ

Are my images uploaded anywhere?
No every image is decoded and re-encoded locally in your browser using JavaScript and the canvas element. Nothing is sent to a server at any point.

How much smaller will my files get?
It depends heavily on the source image, but photos typically shrink by 50-90% at moderate quality settings (60-80%) with little visible difference. Images that are already compressed or low in detail will shrink less.

What's the difference between this and lossless compression?
This tool uses lossy JPEG compression, which discards some image data to achieve much smaller files. Lossless compression preserves every pixel exactly but can't shrink photographic images nearly as dramatically.

Should I compress an image more than once?
Avoid it if possible each JPEG re-compression pass discards more data and can introduce visible artifacts. Always compress from the original, highest-quality version of an image rather than an already-compressed copy.

Can I compress multiple images at once?
Yes drop in as many JPG or PNG files as you like, adjust the quality slider once, and click "Compress Images" to process the whole batch, then download them individually or all at once.