Compress PDF to 400 KB

Reduce a scanned certificate or a few pages to a PDF under 400 KB, with the stamp and small print still readable. See the size first. Free and private.

Before you start

Some portals ask for supporting documents, such as a certificate, a statement or a letter, as a PDF under 400 KB. Shared evenly, that gives 200 KB a page to a 2-page document and 50 KB a page to an 8-page one.

The tool below opens with 400 KB typed in. The Small, Medium and Large cards also show their real sizes, and one of them may already be under 400 KB.

Tips

Keep colour if the document has a coloured stamp, seal or signature that must be seen. "Black & white" turns them grey, and a light stamp can fade.

Have several documents for the same form? Choose them all at once, up to 25. Each one is made under 400 KB, and you can download them together as one ZIP.

Starting from paper? Use the document scanner first. It straightens each page and evens out the light, and then you can make the PDF smaller here.

A checklist for a certificate under 400 KB

Scan or photograph the certificate flat, in daylight, with all four edges in view.

Decide on colour. Keep it if a coloured stamp or seal must be seen. Choose "Black & white" if the page is only printed text.

Press "Make it this size". The 400 KB is already typed in on this page.

Check page 1 in the preview: the stamp, the signature and the smallest print should all be readable.

If the result page shows a DPI under 90, open the downloaded file and zoom in before you upload it.

Questions and answers

Is 400 KB the same as 0.4 MB?

About. It is 400,000 bytes by the metric count and 409,600 bytes on Windows. SafeResize keeps the file under 400,000 bytes, so both counts accept it.

Why is a PDF of text over 400 KB?

It was probably scanned or photographed. A scan stores each page as a picture, even when it looks like text. A PDF saved straight from a word processor is usually much smaller.

My PDF is already under 400 KB. Will it change?

No. The tool says it is already small enough and gives you your original back, with its text still selectable. The one exception is a PDF with editing limits: it is rebuilt, because some websites reject those.