How to Compress Images Online: Complete Guide
Image compression shrinks file sizes without destroying the look you need. Smaller images mean faster pages and lower bandwidth—important for websites, emails, and social media.
Lossless vs Lossy
Lossless compression keeps every pixel and is best for logos and text. Lossy compression discards subtle details and is best for photos, where the difference is barely visible at the right quality level.
Choosing the Right Format
JPEG works well for photos, PNG for graphics with transparency, and WebP often gives the best balance on the web today. Convert first, then compress at a quality you can tolerate.
Dimensions Matter More Than You Think
Halving an image's dimensions cuts its pixel count by four. Resizing to the actual display size often saves more than any compression setting.
Target Sizes for the Web
Aim for under 100 KB for blog images and under 200 KB for larger photos. Test with the tool until the size and quality feel right.
Compressing for Email and Messaging
Email servers reject attachments over a size limit, and messaging apps downscale large photos automatically. Compressing to a reasonable size before sending keeps your images intact and delivers faster.
For documents with many images, compress each picture before inserting it. The total file size drops dramatically compared to compressing the finished document.
How to Compress an Image
- Upload the original image and choose a quality level that still looks acceptable.
- Compare the output file size with your target—usually under 100 KB for the web.
- Export the compressed version and keep the original untouched.
If the size is still too large, resize the dimensions before lowering quality further; dimension cuts save far more than quality tweaks.
Quick tip: aim for consistency across a set—compress all images in a gallery with the same settings so page feel and load behavior stay uniform.