Compress images to a target file size

How to use the compress image to a target size

1. Choose the size limit. Pick 20 KB, 50 KB, 100 KB, 200 KB, 500 KB or 1 MB, or type your own. Upload forms usually state their limit next to the field.
2. Add your images. Drop in one image or a whole batch. A sample photo is loaded first so you can see how it works.
3. Let Refract find the quality. Each image is saved at the highest quality that fits the limit. Only if it still won’t fit at the lowest sensible quality are its dimensions reduced, step by step.
4. Download. Download images one by one or as a ZIP. Images that were already under the limit are left exactly as they were.

How it hits an exact size

File size depends on the picture, so there’s no single quality setting that always gives 100 KB. Refract does what you’d do by hand, many times over: it saves the image at different qualities, homing in on the highest one that stays under your limit. That takes a second or two per image, all on your device.

Which format to choose

JPEG works everywhere, including government and job application forms that only accept .jpg. WebP is usually 25–35% smaller at the same quality, so it keeps more detail under a tight limit, and every current browser supports it. AVIF can be smaller still, but only some browsers can create it and some upload forms reject it.

When the image has to shrink

A large, detailed photo can’t reach 20 KB at full size without looking blocky. Rather than drop to unusable quality, Refract reduces the width and height in steps until a reasonable quality fits. Setting a maximum width yourself, such as 1200px for a website, usually gives a sharper result at the same size.

Frequently asked questions