How to use the image compressor
- 1Drop one or more images onto the box, or click to choose them.
- 2Adjust the quality slider. 70 to 80 keeps photos looking sharp at a much smaller size.
- 3Choose an output format, or leave it on Auto.
- 4Drag the slider on the preview to compare the original and compressed image.
- 5Download each image, or all of them as a ZIP.
How it works
Your images are decoded and re-encoded by your own browser using the canvas API. They never leave your device, which makes this safe for private photos, client work and documents.
Compression works by discarding detail the eye is unlikely to notice. The quality setting controls how much is discarded: lower numbers give smaller files with more visible artefacts.
Choosing a format
- JPG is best for photos. It has no transparency, so transparent areas become white.
- WebP usually gives the smallest files for both photos and graphics, and supports transparency. All modern browsers display it.
- PNG is lossless, so the quality slider does not apply. It suits screenshots, logos and graphics with sharp edges, but is rarely smaller than the original.
- Auto keeps photos as JPG and converts PNG and WebP images to WebP where your browser supports it.
Make images smaller still
Resizing has a bigger effect than quality. A 4000 pixel wide phone photo shown at 1200 pixels on a website wastes most of its data. Turn on Limit width to scale large images down while compressing.
If re-encoding would make a file larger, the original is kept and marked "Already optimized".
Metadata
Re-encoding removes EXIF metadata such as camera details and GPS location, which is good for privacy when sharing photos.
Frequently asked questions
Are my images uploaded to a server?
No. Compression happens in your browser, so your images stay on your device.
What quality setting should I use?
For photos, 70 to 80 is usually indistinguishable from the original at a fraction of the size. Use the comparison slider to check.
Why did my PNG not get smaller?
PNG is lossless, so re-saving it rarely helps. Convert it to WebP for a smaller file, or keep the original if you need exact pixels.
Does compression remove location data from photos?
Yes. Re-encoded images do not keep EXIF metadata such as GPS location or camera details.
How many images can I compress at once?
As many as your device's memory allows. Dozens of typical photos work fine on most computers.
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