How to use this page
- Choose a JPG, PNG or WebP image in the workspace above.
- Keep JPG or WebP selected and confirm the target is 400 KB.
- Compress on this device, check the actual size, then download.
Worked example: a 1600-pixel blog image that must stay under 400 KB
Resize the master to 1600 pixels wide with the resizer, download that, then compress the resized copy to 400 KB here. Compare the preview at the article width, not as a tiny thumbnail. Keep the camera original offline.
What this job is for
For a website, match pixels to the layout first. A 400 KB file that is still 5000 pixels wide is the wrong job. Resize to the column width, then compress. WebP often wins for modern sites; keep JPG if the CMS rejects WebP.
Useful limits
Product shots that also need a marketplace pack should be resized for each channel first. Compress only the export that has a KB limit.
The live tool behind this page is Image Compressor. It is the same local engine as the rest of Image Cosmos.
Frequently asked questions
Is 400 KB large for a phone page?
For one hero it can be acceptable. For a grid of twelve products it is heavy. Use the smallest canvas that still looks sharp.
Why is my 400 KB PNG still huge?
Target KB applies to JPG and WebP. PNG is lossless here and can grow.
Is this processed on a server?
No. Encoding stays in the current browser tab.