Image Compressor
Compress multiple images at once, right in your browser — no upload required.
About Image Compressor
This Image Compressor re-encodes your JPG or PNG images using the browser's native Canvas API (canvas.toBlob) — no upload, no third-party compression service. For JPEG images, the quality slider directly controls your browser's built-in JPEG encoder, so lowering it produces a genuinely smaller file through more aggressive lossy compression; most photos hold up visually well down to around 60-70% quality, with 50%+ size reductions common in that range. PNG works differently: it's a lossless format, and the Canvas API's quality parameter is only defined for JPEG and WebP output — it has no effect on PNG at all, so re-encoding a PNG through this tool won't meaningfully shrink it regardless of where the slider sits. If you need smaller PNGs and don't need transparency, converting to JPEG will get you a real reduction; this tool keeps the original format by default. Upload up to 20 images at once, drag the quality slider to update every image in the batch together, and download individually or all at once — everything happens on your device, so nothing is ever uploaded to a server.
Frequently Asked Questions
No, this tool only adjusts compression quality (reducing file size through more aggressive encoding), not the pixel dimensions of the image.
At quality settings above 60-70%, most JPG images show little visible quality loss while achieving significant file size reduction. Lower settings trade more quality for smaller files.
No, compression happens entirely in your browser using the Canvas API. Your images never leave your device.
PNGs are accepted, but the quality slider has no effect on them — the Canvas API's quality parameter is only defined for JPEG and WebP output, so PNG re-encoding stays lossless regardless of slider position. For real PNG size reduction, converting to JPEG (if you don't need transparency) is the more effective option.
Up to 20 images at a time. Add them all at once or one at a time — the quality slider applies to every image in the batch.
JPEG compression ratio depends heavily on image content — photos with lots of fine detail, noise, or texture compress less at a given quality setting than simpler images with large flat-color areas or smooth gradients, since there's inherently more information to encode.