Compress images without losing quality
Upload a photo, drag the quality slider, and watch the file size drop in real time. Save 60-90% on file size with no visible quality loss. Runs locally, nothing uploaded.
About the image compressor
Image compression is one of the most useful skills on the web. A typical phone photo is 3-8MB; the same photo compressed to JPEG 80 quality is usually 200-500KB with no visible difference at normal viewing sizes. That matters: smaller images mean faster page loads, smaller email attachments, less mobile data, lower hosting bills. Renza's compressor runs in your browser using the Canvas API. Adjust the quality slider and see the resulting file size update instantly. Save when happy. Output is JPEG (the most efficient lossy format) by default; you can switch to WebP for ~30% additional savings.
How it works
Upload your photo. The image compressor prompt is pre-filled. Result in 5 to 15 seconds.
Tips for best results
Things that meaningfully improve the output.
Quality 80 is the sweet spot
Most photos look identical to the original at JPEG quality 80, while being 80-90% smaller. Quality 60 starts showing artifacts on smooth gradients.
Compress at the final size
Resize first (use /tools/image-resizer), then compress. A 4000px image compressed is still huge; a 1600px image compressed is web-ready.
WebP saves another 30%
Switch output to WebP for ~30% smaller files at the same quality. Supported in all modern browsers.
For social media
Most platforms re-compress anyway, so over-optimizing has diminishing returns. Quality 85 is enough.
Frequently asked questions
Is the compression lossless?
No, that is the point. Lossless compression (PNG) usually saves <20%. Lossy JPEG/WebP at quality 80 saves 80-90% with no visible difference.
Does the file get uploaded?
No. Everything happens in your browser.
How small can I make a file?
Down to 5-10% of the original size at quality 70-80 is typical. Below quality 60, artifacts become visible.
Why is my PNG only saving a little?
PNG is lossless and good for graphics, bad for photos. Convert the PNG to JPEG (via /tools/image-converter) if it is a photo.
Is there a file size limit?
No. Practical limit is your browser memory, typically up to 50MB inputs work.