Image Compressor

What this tool does

Image Compressor shrinks photos and graphics directly in your browser. Choose a quality level or a target size in KB, optionally cap the dimensions, and compare the before and after size of every file, then download them one by one or as a single ZIP.

Large images slow down websites, bounce off email attachment limits and get rejected by upload forms that ask for a file under 100 or 200 KB. A phone photo is often 3-6 MB because it is saved at very high quality and at 12 megapixels or more, far more detail than a screen or a form needs.

This compressor re-encodes each image with the browser's own JPEG, WebP or AVIF encoder at the quality you pick, or searches for the highest quality that still fits a target size. PNG files are made smaller by reducing them to an optimised palette of up to 256 colours with median-cut quantisation and optional Floyd-Steinberg dithering, which typically cuts a screenshot or logo by half or more. Every step runs locally, so your photos never leave the device.

How to use Image Compressor

1. Drop one or more images on the upload area, paste one with Ctrl+V, or click Try a sample image.
2. Pick a preset such as Website or Email, or set the Compression mode to By quality or Target size.
3. Choose an Output format: Same as original keeps the type, or convert to WebP or AVIF for smaller files.
4. Optionally set Maximum width or height so oversized photos are scaled down as well.
5. Check the live preview and the percentage saved for the selected file, then press Compress.
6. Download files individually or press Download all (ZIP).

Tips for better results

• For photos, a JPG quality of 70-80% is usually indistinguishable from the original on screen while being several times smaller.
• WebP is roughly 25-35% smaller than JPG at similar visual quality and is supported by every current browser.
• Scaling a 4000 px photo down to 1920 px removes about 77% of the pixels, which saves more than any quality setting.
• Leave Never make a file larger switched on so already-optimised files are kept as they are.

Common use cases

• Getting a passport photo or signature under the 50-200 KB limit of an online application form.
• Optimising product photos and blog images so pages load faster and score better in Core Web Vitals.
• Shrinking a batch of holiday photos before sharing them by email or messaging apps.
• Reducing screenshot PNGs for documentation and support tickets.

Common mistakes to avoid

• Compressing the same JPG repeatedly: each pass adds new artefacts, so always start from the original file.
• Saving photos as PNG to keep quality; a lossless PNG of a photo is often five to ten times larger than a good JPG.
• Choosing a very low target size for a huge photo without allowing it to shrink; the tool will reduce dimensions to reach it, so check the output size.