About the Compress JPG tool
Squeeze JPG photos down for faster websites, smaller email attachments, and quicker uploads. A quality of 70–80% is usually indistinguishable from the original.
Compression happens in your browser using the canvas encoder. Nothing is uploaded, so there is no server-imposed size limit.
How to use it
- Add your JPG files.
- Set a quality level or a target file size.
- Download the compressed images.
Dimensions first, quality second
The single most useful fact about image compression: halving an image's width quarters its file size, because you have removed three-quarters of the pixels.
Dragging the quality slider down is the tool most people reach for first, and it is the one that visibly damages the picture. Resize first, then compress — in that order the same target size looks dramatically better.
What the numbers look like
Measured on the same 1600×900 image at different quality settings:
- Quality 90: 72 KB
- Quality 80: 51 KB
- Quality 60: 37 KB
Dropping from 90 to 80 saved 29% of the file for a difference almost nobody can see. Dropping from 80 to 60 saved a further 27% and starts to show on smooth gradients such as skies.
Common mistakes
- Compressing a JPG that has already been compressed several times. Each pass adds permanent damage.
- Chasing a tiny file with the quality slider alone instead of reducing the dimensions.
- Compressing your only copy. Keep the original somewhere.
Questions people ask
What quality should I use?
80–85 for photographs on a website. Above 90 the file grows quickly for no visible gain.
Can I get the quality back later?
No. JPG compression discards data permanently.
Does compressing repeatedly make it smaller?
Marginally, while making it visibly worse each time. Compress once, from the original.