Guide
How to compress images without losing quality
Published · Updated
You can shrink an image a lot without visible loss, but not with zero loss. The biggest saving is usually to resize the picture to the size it is displayed at; after that, compress it at a quality that still looks right. The image compressor lets you do that in your browser.
Lossless or lossy: what changes
Lossless compression keeps every pixel but saves less. Lossy compression discards detail the eye barely notices and saves much more. JPG and WebP photos are usually lossy; PNG is lossless but can be large for photographs.
Step 1: resize to the display size
A 4000-pixel-wide photo shown at 800 pixels wastes bytes. Use the image resizer to set the width you actually need.
Step 2: compress at a sensible quality
- Add the images to the image compressor.
- Start with the default quality (78) and look at the preview.
- Lower the slider until you notice a difference, then go one step back.
- Download. Several files come as a ZIP.
Choose the right format
- Photos: WebP or JPG give the smallest files.
- Logos and graphics with transparency: PNG or WebP.
- Need another format entirely? The file converter can help.
Images for websites
Smaller images load faster, especially on mobile. Resize to the displayed width, compress, and keep your originals in case you need to export again later. Re-compressing an already compressed JPG can add visible artefacts.
Related tasks
Need a transparent cut-out first? See how to remove an image background. Preparing pictures for social media? See resizing images for Instagram.
Need a specific file size?
If a form or website asks for an image under a size such as 100 KB, see [[post:imageTo100kb|how to reduce image size to 100 KB, 500 KB or 1 MB]].
Questions and answers
Is it possible to compress with no quality loss at all?
Only lossless methods keep every pixel, and they save less. With the quality slider, lower values always remove some detail.
What quality setting should I use?
There is no universal number. Start at 78, check the preview and lower it until you can see a difference.
Are my images uploaded?
No. Compression runs in your browser.