How to Compress Images Without Ruining Them

#Three levers, judged separately

Image file size depends on three independent factors, and separating them is how you find the best result.

Work in this order: check the dimensions first, then the format, then adjust quality. A 4000x3000 photo displayed at 800px wide looks far better when resized than when quality is dropped from 90 to 50.

In practice, drop the image into the Image Compressor and move the quality slider - the tool reports the resulting file size as you go, so you can see exactly how size and quality trade off instead of guessing at a value.

#The payoff from resizing is arithmetic

Halving both dimensions reduces the pixel count to a quarter, because area is width times height: 0.5 x 0.5 = 0.25.

Shrinking 4000px to 1200px keeps roughly 9% of the file size, and on screen the difference is usually invisible, because most display contexts never render that many pixels.

#The JPEG quality sweet spot

A JPEG quality setting of 75-85 offers the best trade-off. Below 60 you get obvious blocking around text and in gradients. Above 90 the file grows quickly while the visible improvement becomes imperceptible.

For a typical photograph, file size behaves roughly like this:

The only reliable test is to zoom to 100% and inspect the critical region. Charts, UI screenshots and images with small text are more sensitive to quality loss; landscapes and portraits tolerate much more.

#When PNG is mandatory

PNG is lossless, meaning every pixel is preserved exactly, and the price is a larger file. Choosing between PNG and JPEG comes down to content:

A common trap: saving screenshots as JPEG. Screenshots are mostly flat colour and sharp edges, exactly what JPEG handles worst. The result is a file that barely shrank and text that smeared. Use PNG, or WebP in lossless mode.

Use the Image Converter when you need to change format - it preserves the PNG alpha channel. To hit an exact size or aspect ratio, crop first with the Image Cropper, then compress.

#Strip EXIF before you share

Phone photos embed EXIF metadata by default, including capture time, device model and GPS coordinates that can be accurate to a few metres. You post a picture of your balcony and a stranger can read your address.

Check what is embedded with the EXIF Viewer. The fields that matter:

#Privacy: local processing versus uploading

Every image tool on this site runs entirely in your browser - images are never uploaded anywhere. You can verify this yourself: open the developer tools network panel, compress an image, and confirm that no upload request occurs.

For images containing contracts, ID documents or internal material, that difference is decisive. A cloud tool means the file has already left your machine.

#Frequently asked questions

#Can a compressed image be restored?

No. Lossy compression discards information permanently, and the compressed file becomes the new original. Archive your source images separately and publish only the compressed copies - never overwrite the original with the result.

#How much does WebP actually save?

At comparable visual quality, lossy WebP is typically 25-35% smaller than JPEG, and lossless WebP is typically 20-30% smaller than PNG. The exact figure depends on content: photographs benefit most, flat-colour graphics less so.

#I set quality to the minimum and the file is still huge. Why?

Because the dimensions did not change. The quality setting only affects how precisely each pixel is encoded; with the same pixel count there is a floor on file size. Reduce the dimensions or switch to WebP - either will help far more than pushing quality lower.

#Does converting to Base64 increase file size?

Yes, always. Base64 encoding enlarges data by about 33%, because binary bytes become printable characters. That makes Base64 suitable only for inlining small icons (under 10 KB); larger images should load as separate files. Use Image to Base64 for the conversion.

#Does batch compression degrade every image?

No - each image is handled independently, and identical settings produce identical results. The real rule is never re-compress an already compressed image: lossy damage accumulates, so a second pass amplifies the artefacts of the first. Always keep an untouched master copy.