Compress Image

Runs in your browser

Shrink image file size with adjustable quality.

Drop a file here or click to browse

This tool runs entirely in your browser. Your data never leaves your device — nothing is uploaded to our servers.

About Compress Image

Image compression is a negotiation between file size and visible artefacts, and the right setting depends entirely on the picture. Photographs with smooth gradients tolerate aggressive JPEG compression; screenshots with sharp text and flat colour show banding and ringing almost immediately. This tool runs entirely in your browser using the Canvas encoder, which means the image is never uploaded anywhere — a meaningful difference when the picture is an ID document or a medical scan.

When to use Compress Image

Meeting a strict KB limit

Job portals and government forms often cap photo uploads at 100 KB or 200 KB. Adjust quality until the reported output size drops under the limit.

Speeding up a website

Unoptimised hero images are the single most common cause of poor Largest Contentful Paint scores. Compressing before upload usually costs nothing visible.

Compressing sensitive images

Passport scans and medical images shouldn't be uploaded to a stranger's server just to make them smaller. Here the pixels never leave your device.

Limitations worth knowing

JPEG compression is lossy and irreversible. Always keep your original; re-compressing an already-compressed image compounds the damage.
PNG screenshots containing text often compress poorly as JPEG — halos appear around letters. Keep them as PNG, or use WebP.
Very large images (above roughly 30–40 megapixels) can exhaust browser memory on low-end mobile devices.
Because processing is local, speed depends on your device rather than a server.

How to compress image

1
Drop the image onto the page — it is read locally and never uploaded.
2
Adjust the quality setting and watch the resulting file size update.
3
Compare the preview against the original, paying attention to text edges and flat areas where artefacts appear first.
4
Download the compressed image once you are happy with the trade-off.

Frequently asked questions

Are my images uploaded to your server?+

No. This tool runs entirely in your browser using the Canvas API. The image is read from your disk into local memory, compressed on your own device, and written back out. Nothing is transmitted — you can verify this by loading the page, disconnecting from the internet, and compressing an image anyway.

What quality setting should I use?+

For photographs, 75–85% is usually indistinguishable from the original at a fraction of the size. For screenshots or images containing text, stay above 90% or use a lossless format instead — sharp edges reveal JPEG artefacts far more readily than photographic detail does.

Why did my PNG get bigger instead of smaller?+

PNG is lossless and already efficient for flat-colour graphics like logos and screenshots. Converting such an image to JPEG can genuinely increase its size while also adding artefacts. If the image has large areas of uniform colour, PNG is already the right format.