Resize Image to 400 KB
400 KB suits a colour scan of a certificate, mark sheet or letter, where stamps, seals and small print all need to stay readable. Everything runs in your browser — nothing is uploaded. Need different dimensions instead? Resize or convert.
Why compress to 400 KB?
A 400 KB target is usually set for website images, email and marketplace listings. A JPG photo of around 1570×1180 pixels fits, with good quality.
About 1570×1180 px fits
At medium quality a detailed JPG photo of roughly 1570×1180 pixels lands under 400 KB; at high quality about 1100×820.
Typical use
400 KB limits are common for website images, email and marketplace listings.
9× smaller than a phone photo
A 12 MP phone photo is around 3–4 MB, so it must shrink about 9×. The tool lowers quality first and resizes only if needed.
Quality to expect
At 400 KB, quality is good. Plenty for web pages, email and on-screen viewing.
Scans and documents
A scanned A4 page of about 1900×2690 pixels usually fits, because text pages compress far better than photos.
Exact limit, checked
400 KB is measured as 409,600 bytes (1 KB = 1,024 bytes), the way most upload forms count it, so the file is never just over.
400 KB at a glance
| Limit in bytes | 409,600 bytes |
|---|---|
| Photo at high quality | about 1100×820 px |
| Photo at medium quality | about 1570×1180 px |
| Photo at low quality | about 2130×1600 px |
| Scanned A4 document | about 1900×2690 px |
| Reduction from a 12 MP phone photo | about 9× |
| Output format | JPG (best for photos), WebP or PNG |
| Typical use | Website images, email and marketplace listings |
Compress an image to 400 KB in 3 steps
- Add your image — JPG, PNG, WebP or a phone photo.
- The target is already set to 400 KB. Leave “Remove EXIF metadata” ticked to save extra bytes.
- Click Compress and download a JPG under 400 KB.
New to image compression? Read the full compression guide.
Certificates and colour scans
Why colour documents are heavy. Seals, signatures and coloured backgrounds add detail the compressor must keep. 400 KB gives a full A4 page room at about 1500–1700 pixels wide.
Straighten before compressing. A tilted photo of a page needs more bytes than a straight one. Crop to the edges with the cropper.
Zoom to check. After compressing, open the result and zoom to the smallest text — roll numbers and dates. If they blur, crop tighter instead of shrinking further.
Other file-size targets
Nearby limits — each one opens the compressor already set to it:
Compress by format
Guides and presets for each format:
Compress under a file size
Keeps your image’s format — pick the limit you need:
JPEG under a file size
Frequently asked questions
How do I keep text readable when compressing a certificate?
Keep the page at least 1500 pixels wide, crop off the background, and check the smallest text after compressing.
How many pixels fit in 400 KB?
For a detailed JPG photo, about 1570×1180 at medium quality or 2130×1600 at low quality. Simple graphics and scans can be much larger.
What quality will a 400 KB photo have?
Good. Plenty for web pages, email and on-screen viewing. The tool keeps the dimensions where it can and lowers compression quality first, so faces and text stay readable.
Is 400 KB the same as 400,000 bytes?
Not quite. Most forms count 1 KB as 1,024 bytes, so 400 KB is 409,600 bytes. The tool uses the same count, so a file it marks as under 400 KB is accepted.
Should I use JPG or WebP for 400 KB?
JPG is accepted everywhere and is the safe choice for forms. WebP holds about 30% more detail at the same size, ideal for websites that support it.
Why is my file still over 400 KB?
Very large or detailed images may not reach 400 KB by quality alone. Resize it first (for example to 1570 pixels wide) with the resizer, then compress again.
Are my images uploaded anywhere?
No. They are read and compressed by your own browser and never leave your device. You can disconnect from the internet once the page has loaded and it will still work.