Compress Image

This usually happens with PNG files. PNG is a lossless format, and re-encoding it through a canvas can produce a larger output. That's why this tool converts PNGs to WebP — WebP supports lossy compression and will reliably reduce file size. JPG and WebP inputs always compress at the quality level you select.

JPG uses lossy compression — great for photos, reduces size significantly. PNG is lossless — preserves every pixel but can't be compressed the same way; we convert it to WebP for real size reduction. WebP is a modern format that combines small file sizes with excellent quality, supporting both lossy and lossless modes.

No — never. All compression happens entirely inside your browser using the HTML5 Canvas API. Your image is read and processed locally on your device. Nothing is ever transmitted to any server, so your photos stay completely private.

For most uses (web, email, social media), 70–80% is a great sweet spot — significant file size reduction with no visible quality loss. Go lower (50–65%) for maximum compression when size is critical. Keep it at 85–90% if you need to preserve fine detail in photos or graphics.