Image Compressor
70–80% is a good balance for photos. Lower means smaller files and more visible artefacts.
If a file can’t be made smaller, the original is kept. JPG output fills transparency with white.
How to use the Image Compressor
- Choose images or drag and drop them onto the box. JPG, PNG and WebP are supported, one file or many.
- Each file is compressed straight away. Move the quality slider or change the output format and every file is compressed again.
- Check the size saved on each file, then download files one by one or use Download all.
Examples
- A 4.2 MB phone photo for an email or a website. At 75% quality, JPG photos often shrink by half or more with no difference you can see at normal size. The exact saving depends on the photo.
- A PNG screenshot that is too large to upload. PNG is lossless, so recompressing it as PNG rarely saves much. Choosing WebP as the output usually makes it several times smaller.
- An image that is already optimised. If no smaller version can be made, the tool keeps your original and says so, so you never download a bigger file by mistake.
How image compression works
Your browser decodes each image and encodes it again with the settings you choose. All of this happens on your device, in a background worker, so the page stays responsive during large batches.
Supported formats
- JPG: lossy. The quality setting controls the trade-off between size and detail.
- WebP: lossy here, and usually 25–35% smaller than JPG at similar quality. It works in all current browsers, but some older apps and upload forms reject it.
- PNG: lossless. Recompressing as PNG never loses quality, but browsers have no setting to make it smaller, so savings are small. Convert PNG photos and screenshots to WebP or JPG for big savings.
Files are recognised by their contents, not their names. A PNG saved as photo.jpg is compressed as a PNG and downloaded with the right extension.
Quality vs file size
Lower quality removes more fine detail. Around 70–80% is a good balance for photos on the web. Text, logos and sharp edges show artefacts sooner, so use a higher setting or WebP for them. JPG and WebP compression here is lossy: the output is not identical to the original, even when it looks the same.
Privacy
Images never leave your device: there is no upload and no server processing. You can check this by loading the page, switching off your internet connection and compressing a file. Re-encoding also drops metadata such as camera details and GPS location from the output, which is useful before sharing photos.
Frequently asked questions
Is this image compressor lossless?
Only for PNG output. JPG and WebP output is lossy: it removes detail you are unlikely to notice in exchange for a much smaller file. At high quality settings the difference is very hard to see.
Why didn't my file get smaller?
It was probably already well compressed, or it is a PNG kept as PNG. When the result would not be smaller, the original is kept. Try a lower quality, or WebP as the output format.
Is there a file size limit?
Each file can be up to 100 MB. Very large images, roughly above 16,000 pixels on a side, can exceed what some browsers can draw, especially on phones. Those files show an error instead of a result.
What happens to transparent areas?
PNG and WebP output keep transparency. JPG cannot store it, so transparent pixels become white when you choose JPG output.
Are animated images supported?
No. GIF files are not accepted, and an animated WebP is compressed as a still image of its first frame. The file list marks it so this doesn’t catch you out.
Does compression change the image dimensions?
No. The width and height stay the same; only the file size changes. Each finished file shows its dimensions.
Related tools
Last updated