Image Compressor
Browser-based image processing powered by WebAssembly
Frequently Asked Questions
Will compression reduce image quality?
Not noticeably, if you do it right. The tool uses adjustable quality with a live before/after comparison, so you can push the file smaller while confirming it still looks sharp. For most photos, quality around 75–85% is visually identical to the original at normal viewing size — you only start to see artifacts if you drop the quality very low.
Are my images uploaded to a server?
No — nothing is uploaded. Compression runs entirely in your browser using WebAssembly, so your images never touch a server. That matters for personal photos, screenshots with sensitive information, or client work under NDA, where keeping the file on your own device is worth far more than a few saved kilobytes.
Which formats are supported, and can I batch?
JPEG, PNG, WebP and AVIF are all supported, and you can drop in many images at once for batch compression and download them together as a zip. It's completely free with no sign-up and no watermark — the only limit on batch size is your own device's speed.
How much smaller can the file get?
Usually a lot. Converting a photo to WebP or AVIF at around 80% quality typically cuts the file by 60–80% with no visible difference at normal size — a 9 MB PNG screenshot, for example, often comes out around 1 MB as WebP. Resizing oversized images on top of that saves even more.
Can I resize the image while compressing?
Yes. You can set a target width — 1600px is plenty for web use — and the tool resizes as it compresses. This is the step most people skip, yet a 6000px phone photo shown at 1200px is carrying four times the pixels it needs, so resizing is often the single biggest size saving you can make.
Which output format should I choose?
WebP is the best all-round choice: about 25–35% smaller than JPEG at the same quality, with wide browser support. AVIF goes smaller still if you want the absolute minimum file size. Keep JPEG only when you need maximum compatibility with older software or email clients that don't handle WebP.
Is there a limit on file size or number of images?
There's no hard limit on file size or the number of images. Because everything runs locally on your device rather than on a server, very large images or big batches simply depend on your machine's memory and speed — on a modern computer you can comfortably process dozens at once.