Click to upload or drag & drop images
JPG, PNG or WebP — select multiple files at once
Lossy vs lossless compression
Image compression shrinks file size by removing data — the question is which data. Lossy compression (JPEG, WebP at lower quality) throws away detail the human eye barely notices, like subtle color gradients, which is why the quality slider above trades visual fidelity for smaller files. Lossless compression (PNG) repacks the same pixel data more efficiently without discarding anything, so the image is pixel-for-pixel identical but the size savings are smaller and more limited.
Why JPEG compresses photos better than PNG
Photos are full of smooth gradients and subtle noise — exactly what JPEG's lossy algorithm is built to discard with little visible impact, often shrinking a photo by 70–90% at moderate quality settings. PNG's lossless compression has to preserve every pixel exactly, which works great for screenshots, logos, and graphics with flat colors and sharp edges, but produces much larger files for photographic content. WebP sits in between, offering both lossy and lossless modes with generally better compression than either JPEG or PNG at a given quality level.
Frequently asked questions
Does compression reduce image dimensions or just file size?
Just file size. This tool doesn't change the pixel dimensions of your image — the quality slider only adjusts how much detail is discarded during encoding. If you also need to shrink the width or height, use the Image Resizer.
What's the difference between lossy and lossless compression?
Lossy compression (JPEG, WebP) permanently discards some image data to achieve much smaller files, with a small drop in visual quality at higher compression. Lossless compression (PNG) keeps every pixel exactly as it was, so file size savings are smaller but nothing is lost.
How much smaller will my file get?
It depends heavily on the source image and format, but photos re-encoded as JPEG or WebP at 70–85% quality typically shrink by 60–90% with minimal visible difference. PNGs of photographic content usually see much smaller reductions since PNG is already lossless.
Are my images uploaded anywhere?
No. Compression happens entirely in your browser using the Canvas API — your images never leave your device or touch a server.