How to Compress an Image Without Losing Quality
“File too large” is the most annoying error when you're attaching a photo or uploading to a website. The good news: most images can be made dramatically smaller with almost no visible difference. Here's how to compress an image the right way — and it all happens in your browser, so your photos are never uploaded anywhere.
Compress an image
Use the Compress Image tool:
- Open Compress Image and drop in your JPG or PNG.
- Adjust the quality until the size and look are right.
- Download the smaller file.
The two things that actually shrink a file
- Dimensions.A 6000×4000 photo has far more pixels than any screen needs. If you only display it at 1200px wide, resize it first — this is usually the single biggest saving.
- Quality (compression level). JPGs let you trade a little visual detail for a much smaller file. Dropping from 100% to ~75% quality is typically invisible but can halve the size.
Tips for keeping it sharp
- Resize before you compress. Match the dimensions to where the image will be shown.
- Use JPG for photos, PNG for graphics with flat colors or transparency.
- Try WebP for the web — it's smaller than JPG at the same quality (see below).
- Keep the original. Compression is lossy, so archive the full-size version.
Go further
Switching format can shrink things even more — convert to WebP with the Image Converter. Got a whole folder to process? The Bulk Image Converter & Resizer handles many at once. Explore all our image tools for more.
FAQ
Are my images uploaded to a server?
No — compression runs entirely in your browser, so your images never leave your device.
Will compressing ruin the quality?
Not if done sensibly. Resizing to the dimensions you actually need, plus moderate quality, keeps images looking crisp while cutting the file size a lot.
What's the best format for small files?
WebP usually gives the smallest files at a given quality; JPG is the safe, universal choice for photos.