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Compress images
Reduce the size of your photos and images for the web, email or social media. The size before, after and the actual measured savings are shown for each image.
JPG, PNG, WebP, AVIF · up to 30 images at once
Choose images- Processed in your browser by default
- Free, no account
- Metadata (GPS) removed
How to do it
Drop your images
JPG, PNG, WebP or AVIF, up to 30 at once.
Set the quality
The lower the quality, the lighter the file. 75% is a good starting point for a photo.
Compare and download
If an image cannot be made lighter, you get it back unchanged, never heavier.
How compression works
For JPG and WebP, lossy compression removes details the eye barely notices. The quality slider sets the trade-off: at 75-80%, savings often reach 50 to 70% with no visible difference on a photo.
For PNG, the image is reduced to at most 256 carefully chosen colors and saved as an indexed PNG, the same technique as pngquant or TinyPNG. Transparency is kept, and the file often shrinks by 60 to 80%. An image that already has few colors loses nothing at all. This also happens in your browser.
If the file does not shrink
An image that is already heavily compressed can come out heavier after re-encoding. In that case, ImageOptimizer keeps the original file and tells you so: you never download an image heavier than the one you started with by mistake.
To save more, set the output format to WebP, or reduce the dimensions with the resize tool.
Frequently asked questions
What is the best quality setting?
Between 70 and 80% for a photo on a website. Compare with the original before publishing: that is what the before/after thumbnails are for.
How are PNG files compressed?
The number of colors is reduced to at most 256 (fewer if you lower the quality below 60%), and the PNG is saved with a palette. Transparency is kept. If the result is not lighter, the original is returned unchanged.
Are my images uploaded to a server?
No, unless the file is in a format your browser cannot read. The interface warns you in that case.
Does compression remove metadata?
Yes: EXIF and GPS information is not kept in the compressed image. If the image cannot be made lighter, the original is returned as is, metadata included.