Privacy Tool
Image Compressor
Shrink images with the same WASM codecs as Squoosh — MozJPEG, WebP, AVIF and OxiPNG. Everything runs in your browser; your image is never uploaded.
Powered by jSquash, the WebAssembly codecs behind Google's Squoosh. Images are decoded, optionally resized, and re-encoded entirely on your device — nothing is sent to a server. AVIF gives the smallest files but encodes slower, especially on large images.
How the Image Compressor works
This free image compressor shrinks JPEG, PNG, WebP, and AVIF files using the exact WebAssembly codecs that power Google's Squoosh — MozJPEG, OxiPNG, WebP, and AVIF. Drop in an image, choose a format and quality, and the tool decodes, optionally resizes, and re-encodes it right inside your browser. Because everything runs locally, your images are never uploaded and there are no size limits or daily quotas.
Large, unoptimized images are the most common cause of slow pages. Compressing them is one of the highest-impact things you can do for Core Web Vitals: a smaller hero image loads faster, improving Largest Contentful Paint (LCP), reducing bandwidth, and helping your mobile search rankings.
Which format should I choose?
- AVIF — the smallest files at a given quality; best when you can afford a slower encode and target modern browsers.
- WebP — excellent size with near-universal support; the safe default for most photos.
- MozJPEG — the best universal format for photographs when you need maximum compatibility.
- PNG — lossless (optimized with OxiPNG); use for logos, icons, screenshots, and images with transparency.
A quality of 70-80 usually cuts photo file size by 60-80% with no visible loss. Use the before/after preview and the savings badge to find the right balance, and enable Resize to cap the maximum width for even smaller files.
Frequently Asked Questions
Is my image uploaded to a server?
No. The Image Compressor runs entirely in your browser using WebAssembly. Your image is decoded, resized, and re-encoded on your own device — it is never uploaded, stored, or sent anywhere, so it works even offline.
What is the difference between WebP, AVIF, JPEG, and PNG?
AVIF gives the smallest files at the same quality but encodes slowest. WebP is a great all-round choice with smaller sizes than JPEG and near-universal browser support. MozJPEG is the best universal format for photographs. PNG is lossless and best for graphics, logos, and screenshots with sharp edges or transparency.
How much can I compress an image without losing quality?
For most photos a quality setting of 70-80 reduces file size by 60-80% with no visible difference. Lower values shrink files further at the cost of visible artifacts. Use the before/after preview and the size savings badge to find the sweet spot for each image.
Does compressing an image reduce its dimensions?
Not unless you enable the Resize option. By default the pixel dimensions stay the same and only the file is re-encoded. Turning on Resize and setting a maximum width scales the image down (keeping aspect ratio), which reduces the file size even more.
Why does image compression matter for SEO?
Images are usually the largest assets on a page. Smaller images load faster, which improves Largest Contentful Paint (LCP) and overall Core Web Vitals — confirmed Google ranking signals. Faster pages also reduce bounce rates and improve mobile rankings.
Which image format is best for the web?
Serve AVIF or WebP with a JPEG fallback for photographs, and PNG (or WebP) for graphics with transparency. AVIF and WebP typically cut file size 25-50% versus JPEG at the same perceived quality, making them the best choice for Core Web Vitals.
Is there a file size or image count limit?
There is no hard limit because processing happens locally. Very large images (4000px and above) take a few seconds to encode in AVIF since it runs single-threaded, but there is no upload size cap or daily quota.
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