Compress an image without uploading it
Drop in an image and squeeze the file size down. It never leaves your browser.
Image compressor
JPEG, PNG, WebP, GIF, or BMP. Nothing is uploaded.
The image is scaled to fit inside these bounds, keeping its proportions. Leave one blank to limit only the other. Images are never enlarged.
- Original
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- Compressed
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- Dimensions
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Getting a smaller file without a worse image
Two things determine the size of an image file, and only one of them is the quality slider:
- Dimensions matter more than quality. Halving the width and height quarters the pixel count. A 4000px photo displayed in a 800px column is carrying sixteen times more data than it can show. Resizing first is almost always the bigger win.
- Quality has a floor of diminishing returns. Between 100 and about 80 you lose file size and almost no visible detail. Below roughly 60 the artefacts become obvious, especially around text and sharp edges. 80 is a good default.
For a photograph on a web page, 1920px wide at quality 80 in WebP is a reasonable target and will usually land somewhere between 100 and 300 KB — often a tenth of what came off the camera.
Common questions
Is my image uploaded anywhere?
No, and this is the main reason to use this page rather than most alternatives. The image is decoded, resized, and re-encoded by your own browser using the canvas API. It is never sent to a server, which means it cannot be stored, scanned, or leaked — and the page keeps working with no network connection at all.
Which format should I choose?
WebP for photographs, almost always — it is roughly 25 to 35 percent smaller than JPEG at the same visible quality and every current browser supports it. Keep PNG if the image has transparency or is a flat-colour graphic such as a logo or screenshot of text, both of which JPEG and WebP smear. Use JPEG only when something downstream cannot read WebP.
Why did my file get bigger?
Usually because it was already well optimised, or because it is a flat graphic being re-encoded as a photograph format. Re-encoding always loses a little and occasionally costs more than it saves. The comparison is shown before you download, so you can see it happen and keep the original instead.
Does compressing twice halve the size again?
No, and it will visibly degrade the image. Lossy compression discards detail permanently, so a second pass throws away information from an already-reduced version rather than from the original. Always compress from the original file.
Why can I not use a HEIC photo from my iPhone?
Browsers cannot decode HEIC, so there is nothing this page could do with it. On an iPhone you can change Settings, Camera, Formats to Most Compatible to capture JPEG instead, or share the photo in a way that converts it — sending it to yourself in most apps produces a JPEG.