Image Compressor

How to compress an image

1. Drop an image onto the box or click to browse. Compression runs immediately at the default settings.
2. Read the three stats: original size, compressed size, and percent saved. A live preview of the compressed result shows below them.
3. Move the quality slider (10 to 100, default 75) and watch the size and preview update in real time. Switch the output between WebP, JPEG, and lossless PNG.
4. Click Download compressed. The file is named after the original with a -compressed suffix and the right extension.

A worked example

Take a 4.8 MB photo straight off a phone camera and drop it in. At the default WebP quality 75, the compressed stat typically lands somewhere in the few-hundred-kilobyte range with the saved figure reading 85 to 90 percent, and at normal viewing sizes the preview is indistinguishable from the original. Nudge the slider down to 50 and watch the size fall further while artifacts start creeping into smooth areas like skies; nudge it to 90 and the file grows substantially for sharpness you mostly cannot see. That live loop, adjust and immediately see both the size and the picture, is the honest way to pick a quality setting, and it is why this tool recompresses on every slider movement instead of making you click a button.

What actually happens to the file

The image is decoded and redrawn onto a canvas at its original pixel dimensions, then re-encoded by your browser's own codec in the format and quality you chose. Nothing is uploaded; the entire pipeline runs on your device, which is also why it is faster than upload-based compressors. Two side effects are worth knowing. First, canvas re-encoding strips all metadata, including EXIF GPS coordinates, so a compressed photo is also a location-scrubbed photo, a genuine privacy benefit before posting publicly. Second, when you pick JPEG output, transparent regions are flattened onto white, because JPEG has no transparency; keep WebP or PNG when transparency matters. The PNG option ignores the quality slider entirely, since PNG is lossless by definition.

Honest limitations

Compression here changes encoding quality, not dimensions: a 6000 pixel wide photo stays 6000 pixels wide. Often the biggest savings come from resizing first, then compressing, and the image resizer on this site handles the first half. Results depend on your browser's encoders, so exact sizes differ slightly between Chrome, Firefox, and Safari, and one real gap exists: Safari cannot encode WebP via canvas, so choose JPEG there if the WebP option errors. Screenshots and text-heavy graphics compress poorly as JPEG and show fuzzy halos around letters; use WebP or PNG for those. And one file at a time, no batch mode, which keeps the interface instant but makes a 50-image folder a job for a desktop tool.