Compression
Image Compressor & Resizer
Shrink a photo's file size and dimensions with live before/after comparison — no uploads, no waiting on a server.
Your files never leave your browser. Nothing is uploaded, stored, or seen by us.
How it works
Your image is decoded and redrawn onto an in-memory HTML canvas sized to your chosen max width, then re-exported at your chosen quality and format using the browser's native canvas.toBlob() API. Adjust any slider and the result updates instantly — all computation happens on your device.
Frequently asked questions
- How does this compress an image without uploading it?
- The image is redrawn onto an in-memory canvas at your chosen width, then re-encoded at your chosen quality and format using the browser's built-in Canvas API. All of that happens locally — nothing is sent to a server.
- Which format should I choose?
- WebP typically gives the smallest file size at a given quality and is supported by all modern browsers. JPEG is the safest universal choice for photos. PNG is best only for images that need transparency or sharp edges like screenshots and logos — it doesn't use the quality slider since PNG compression is lossless.
- Will resizing reduce image quality?
- Reducing the max width scales the image down, which is a one-way change — you can't get the original resolution back from the compressed file. Lowering the quality slider (for JPEG/WebP) introduces compression artifacts. Both are trade-offs between file size and fidelity that you control with the sliders.
- Is my image uploaded to a server to compress it?
- No. Compression happens entirely in your browser using the Canvas API. Your original file is never transmitted anywhere.