Compress Image - Free Online Browser Tool

Make images smaller by lowering their quality, in your browser. Batch the lot, nothing is uploaded.

An image is too big for a form that wants 2 MB, or an email that will not accept 8, or a page that has gone slow on a phone connection. The file is usually not too complicated - it is too big, and the size comes almost entirely from two things: how many pixels it has, and how carefully each one is encoded. This tool attacks both. A quality setting decides how much detail the encoder throws away, and an optional width cap removes pixels outright. The order in which to reach for them matters: removing pixels you were never going to look at costs nothing in quality, while lowering quality is a visible trade. A 4000-pixel photograph sent to a phone rarely needs to stay 4000 pixels wide, and capping it usually does more for the file size than any amount of quality reduction. Choose the format that suits the picture while you are there - JPEG for photographs, WebP for the smallest result, PNG for flat artwork and text where artefacts are much more obvious. Files are processed in this tab and never uploaded, so a batch of photographs you would not want on a third party's server stays on your own machine.

This compress image utility runs completely inside your web browser. Your document is opened locally and processed on your own device using JavaScript and WebAssembly, so your file is never uploaded to any server. There is no signup, no watermark and no limit on how many documents you can handle.

  • 100% client-side - files never leave your device
  • Instant processing, no upload wait
  • Works on desktop, tablet and mobile
  • Free forever, no account required

Common next steps: Image Converter, Resize Image, Compress PDF, JPG to PDF.

How to Use the Compress Image Tool

Four steps, and the whole thing runs locally on your own device.

  1. Pick how much to give up

    Start at 70%, which is where most photographs stop looking compressed to the eye. Go lower only when you need the bytes, and remember what you are trading.

  2. Cap the width as well

    Type the width you actually need, or 0 to leave the dimensions alone. For a web page or an email this is usually where most of the saving comes from.

  3. Choose the format

    JPEG for photographs, WebP for the smallest file, PNG for screenshots and flat artwork where a lossy format smears edges and text.

  4. Download and compare

    The report inside the archive records the before and after size of every file, so you can see which ones were already as small as they needed to be.

Frequently Asked Questions

How small can it go before it looks bad?

For a photograph shown at ordinary sizes on screen, 70 to 80% is usually invisible. Below about 50% the artefacts start appearing as smudging in skies and blotches in skin, and text in an image turns to mush well before that.

Why is my PNG bigger after compressing it?

PNG is lossless, so a quality setting does nothing to it - the size only moves if you cap the dimensions. If the picture is a photograph, converting it to JPEG or WebP is the change that makes a real difference.

Does compressing remove the metadata?

The picture is decoded to a canvas and re-encoded, and a canvas holds pixels rather than the original file's metadata, so EXIF, camera details and location data do not survive. For most uses that is a bonus, but it does mean a file stripped this way can no longer prove when or where it was taken.

Will compressing ever make a file bigger?

Yes - an image already saved at a very low quality can grow when it is re-encoded, and a small PNG that is asked to stay a PNG will barely move. The report records the original size next to the new one so you can see it rather than guess.

Is there a limit on how many I can do?

Only what your device can hold in memory while it works, which is far more than you would expect for photographs. The files are processed one at a time, so a long batch keeps running without the tab freezing.