PNG files are saved as WebP for real size savings.
About this tool
Large images slow pages down and eat storage. Compressing them reduces the file size — by lowering quality slightly and optionally shrinking the dimensions — while keeping the picture visually close to the original. This is the single biggest win for web performance and for fitting images under upload limits.
The compression runs in a Web Worker, so even large photos are processed without freezing the page. Drop one or many images, tune the quality slider and max dimension, and each result shows the before and after size and the percentage saved. Download them one by one or as a ZIP — all locally, with no upload.
Compression runs in a Web Worker in your browser — images are never uploaded.
Frequently asked questions
How do I compress an image without losing quality?
Keep the quality slider high (around 0.8) and let the tool re-encode the image — most photos shrink 60–80% with no visible difference. It shows the before and after size and the percentage saved for every file, so you can lower quality only as far as still looks good.
Are my images uploaded when compressing?
No. Compression runs entirely in your browser using a Web Worker, so the image data never leaves your device and nothing is sent to a server. That makes it safe for private or sensitive images, and it works offline once the page has loaded.
How much smaller will my images get?
It depends on the source and your settings — photos often shrink 60–80% at a quality of around 0.7–0.8 with little visible loss. The tool shows the exact savings for each file so you can dial it in.
Does it change the image format?
JPG and WebP keep their format. PNG is saved as WebP, because PNG is lossless — re-encoding it as PNG cannot reduce the size and often increases it, whereas WebP gives real, quality-adjustable savings with transparency preserved. The output is never larger than the original.
Why does it stay responsive with big images?
The heavy decode and re-encode happen in a Web Worker, off the main thread, so the page keeps responding while images process.