Drop any JPEG, PNG, or WebP and get back a compressed version in seconds — smaller file, same visual quality, nothing uploaded to a server. Adjust the quality slider, pick an output format, and download. Everything runs locally in your browser.
Why image size matters
Images are the single largest contributor to page weight on most websites. A hero image that hasn't been compressed can easily weigh 4–8 MB straight from a camera or design tool. That one file can make a page take 6+ seconds to load on a mid-range mobile connection — long enough for most visitors to leave before they've seen anything.
Search engines measure page load speed as a ranking signal. Google's Core Web Vitals assessment penalises slow Largest Contentful Paint (LCP), which is almost always an image. Compressing images is the highest-impact, lowest-effort performance improvement available for most sites: it requires no code changes, no infrastructure work, and can be done before any asset is uploaded to a CMS or CDN.
JPEG, PNG, and WebP — which to use
Choosing the right format is as important as choosing the right quality level.
JPEG is the standard for photographs and images with complex gradients. It uses lossy compression — some detail is discarded to achieve smaller sizes — but at quality settings of 75–85%, the difference is invisible to the human eye at normal viewing distances. JPEG does not support transparency. It is the right choice for hero images, product photography, blog post thumbnails, and any image where file size matters more than pixel-perfect fidelity.
PNG uses lossless compression, meaning every pixel is preserved exactly. File sizes are larger than JPEG for photographs, but PNG is the correct choice whenever you need a transparent background — logos, icons, illustrations, UI mockups, and product cutouts where the subject sits on a coloured or patterned background. Reducing quality on a PNG compresses the file with a lossy pass before the lossless stage, which can yield meaningful size reductions on complex images while keeping edges clean.
WebP is a modern format developed by Google that typically produces files 25–35% smaller than JPEG or PNG at equivalent visual quality. It supports both lossy and lossless compression in the same format, and it supports transparency. Browser support is now universal across Chrome, Safari, Firefox, and Edge. If your stack can serve WebP — most CDNs and image services do automatically — it is the best default for web use. The only reason not to use it is if you need the file to open in older desktop software that doesn't support it.
Understanding the quality slider
The quality percentage controls how aggressively the compression algorithm discards visual information.
At 90–100%, the output is nearly indistinguishable from the original. File sizes are only marginally smaller than the source. Use this range when the image will be printed, used in video, or examined closely at full resolution — not for general web use.
At 75–85%, the sweet spot for most web images, compression is substantial — often 60–75% smaller than the original — and the difference is invisible at normal display sizes. This is the right default for hero images, product photos, and editorial photography.
At 50–70%, file sizes drop significantly again and visible artifacts begin to appear at full zoom, particularly around high-contrast edges and text rendered in images. Acceptable for thumbnails, preview images, and anywhere images are displayed small.
Below 50%, artifacts become visible at normal viewing sizes. Useful only for placeholder images, low-fidelity previews, or situations where bandwidth is the absolute priority over quality.
Batch workflow
The tool processes one image at a time, but you can run it repeatedly without refreshing the page — upload a new file after downloading the previous result. For large batches, consider running images through this tool at the settings you've dialed in, then uploading the compressed versions to your CMS, CDN, or design system. The output files are standard JPEG, PNG, or WebP and will open in any application that supports those formats.
How it works
Compression runs entirely inside your browser using the Web Workers API — no file is ever sent to a server. Your images stay on your device throughout the entire process. This means the tool works offline once the page has loaded, there are no file size limits imposed by a server upload endpoint, and processing speed is determined by your device rather than a remote queue.
The underlying compression is handled by a WebAssembly-accelerated codec running in a background thread, so the browser UI stays responsive while large images are being processed.
How to use it
Drag your image onto the upload area or click to browse. Set your quality level and output format, then click Compress. The before-and-after comparison appears below, showing the original file size, the compressed file size, and the percentage reduction. Click Download to save the compressed file. If the result isn't quite right — too much quality lost, or not small enough — adjust the slider and compress again without re-uploading.
Free to use, no account required, nothing leaves your browser.