Skip to content

Compress a PDF to 50KB

50 KB is realistic only for a single-page document, and in our tests not for a scanned one. Compress can open with 50 KB already chosen: it reads your PDF on your device, works out before it runs whether even its lowest picture quality can get there, and tells you plainly when a file will not fit. When one does fit, you see the size of the finished file before you download it.

Updated

Compress a PDF to 50 KB

What can get down to 50 KB

  • A phone photo of one page, saved as a PDF — only just. In our tests a photo of a page from a 12-megapixel phone camera reached 50 KB only at the lowest quality setting, so read the small print in the preview before you upload it.
  • One typed page with a small picture on it, such as an application form with a photo, as long as the fonts built into it are small. Our test page used a font that PDF readers already carry, so the file held none, and it came out at under 17 KB without going below the Recommended setting.

What usually stays over 50 KB

  • A single page scanned in color at 300 DPI. In our tests the lowest setting was estimated to leave it at about 83 KB, so Compress said at the start that it could not get it under 50 KB, without running.
  • Two or more scanned or photographed pages. Even one scanned page was too big for 50 KB in our tests, and every extra page brings a picture of its own.
  • A typed document that carries whole fonts inside it. Our three-page plain-text test file was 84 KB of text and fonts, which Compress does not rebuild, so a file like that will not fit in 50 KB.
  • A scan over 50 KB from an app that stores its pages in a lossless format rather than as JPEG: Compress cannot re-save those, so it stays the size your scanning app made it. And a PDF locked with a password, which Compress cannot open.

More on this: Why PDF files get large.

If your PDF stays over 50 KB

Photograph the page with your phone

In our tests a phone photo of a page got under 50 KB where a 300 DPI scan of a page could not. Photograph the single page flat and in good light, turn the photo into a PDF with JPG to PDF, then compress that PDF. An iPhone saves photos as HEIC unless its camera format is set to Most Compatible, and JPG to PDF needs a JPG.

Open JPG to PDF

Crop the scan before it becomes a PDF

A small document such as an ID card, scanned on a full A4 scanner glass, carries a page's worth of empty lid around it. Crop to the card in your scanning app, before saving it as a PDF, so the picture holds only the card.

One page per upload

50 KB is a one-page budget. If the form has a separate upload for each certificate, split a combined PDF with Split PDF and compress each page by itself.

Open Split PDF

Forms and a 50 KB limit

We found no upload form that caps a PDF document at 50 KB in the official instructions we could read on September 30, 2026. The 50 KB maximums we read there were for photographs, signatures and hand-written declarations uploaded as images, and where a PDF certificate was mentioned beside 50 KB, 50 KB was its minimum rather than its maximum. That is why this page quotes no form. Check your own form's instructions for both limits, and for the file type it wants.

A different size

Aiming for a different size? Each of these has its own page.

If you have no set size to hit, open Compress PDF without a target and choose from the sizes it offers for your file.

Compress runs in your browser. Your PDF is not uploaded, there is no account, and no watermark is added to the smaller copy.