Compress PDF to 50 KB

Get a one-page PDF under 50 KB for a strict upload form. Tick black and white, check the preview, then download. Free, and your PDF stays on your device.

Before you start

50 KB is one of the smallest limits a form can set for a PDF. It suits a single page, such as a certificate, a letter or a signed form. A phone scan of one page is often 1 MB or more, so it has to lose about 95% of its size.

The PDF tool below opens with 50 KB typed in. Add your PDF and press "Make it this size". The tool lowers the sharpness step by step until the file fits, and the result page shows page 1 exactly as it was saved.

Tips

Photographing the page? Use daylight and hold the phone straight above it. An even, bright page shrinks better than a dim, grainy one.

Starting from paper? Scan only the page, with no table or shadow around it. The document scanner finds the edges of the page and cuts the rest away.

A PDF saved straight from a word processor may already be under 50 KB. If it is, the tool says so and you keep your original, with its text still selectable.

A checklist for a 50 KB PDF

Check whether 50 KB is for the whole PDF or for each page. If it is for each page, split the PDF into single pages in your PDF program first.

Take out every page the form does not ask for. One page gets all of the 50 KB, while five pages get about 10 KB each.

Tick "Black & white" if the page is mostly text. A grey page needs much less space than a colour one, so the text can stay sharper.

Press "Make it this size" and look at the DPI on the result page. Below 90 DPI, the result page asks you to zoom in and check the small text.

Open the downloaded file and read the smallest print on it before you upload it.

Questions and answers

Can every PDF be made 50 KB?

No. A long document, or pages full of photos, may not fit even at the lowest sharpness. Then the tool says it could not get under 50 KB and shows the smallest size it could make, so you know how far off you are.

How low does the sharpness go?

The tool tries 150, 120, 96, 72, 56 and then 45 DPI, and stops at the first that fits. At 45 DPI an A4 page is a picture of about 372 × 526 pixels, so small print can be hard to read. The result page shows the DPI it used.

Should I type 50 or 49?

Type 50. SafeResize keeps the file under 50,000 bytes, which is under 50 KB whether a website counts 1,000 or 1,024 bytes to a KB.