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Compress a PDF to 400KB

A 400 KB limit is generous for one scanned page and workable for two or three. Choose 400 KB in Compress and it starts from the highest picture quality it expects to fit, steps down only when the file needs it, and reports the size the finished PDF really came to. All of it happens in your browser. A scan with many pages will not fit at any quality, and Compress tells you before it runs when it can see that coming.

Updated

Compress a PDF to 400 KB

What fits in 400 KB

  • One page scanned in color at 300 DPI. A page of our test scans came to about 360 KB at the Recommended setting, so a single page like it fits without going lower.
  • Two or three scanned pages, at a lower setting. Our two-page scan fitted 300 KB one step above the lowest, so 400 KB can give a pair of pages a little more quality than that.
  • A phone photo of a document, which fitted under 300 KB at the Recommended setting in our tests.

What will not fit in 400 KB

  • A color scan of five pages or more. At the lowest step each page of our test scans was a little over 80 KB, so five of them already pass 400 KB.
  • A file whose weight is the fonts built into it, since Compress makes pictures smaller and leaves fonts as they are.
  • Scanned pages a scanning app saved without JPEG compression, which Compress does not re-save.
  • A PDF locked with a password, which Compress cannot read.

More on this: Why PDF files get large.

If your PDF stays over 400 KB

Make one file per document

A form with a separate upload for each certificate gives each one its own 400 KB. Split PDF cuts a combined scan into those separate files.

Open Split PDF

Take out the pages nobody asked for

Blank reverse sides, instructions pages and duplicates each carry a whole page of picture. Remove them with Delete PDF Pages, then compress what is left.

Open Delete PDF Pages

Change how the scan is saved

When Compress hardly changes a scan, its pages are probably stored losslessly. Set the scanning app to save JPEG pages, scan again, and compress the new file.

Forms that ask for 400 KB

No form is quoted on this page yet: a limit appears here only after we have read it on its publisher's page and noted the date, and we have not read a 400 KB limit that way. Your form's own instructions are the authority.

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.

If the form asks you to resize the PDF, it means the file size: Resize PDF does the same job under that name and leaves every page its own size.

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