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OS Authority

Compress a PDF to under 100 KB

Try to fit a PDF under a strict 100 KB upload cap. This small budget suits short documents; inspect the result because longer scans may stay over the limit.

Your PDF is processed on this device and never uploaded. We don't see, store or log your files.

Common sizes

How it works

  1. Tap Choose file and pick your PDF.
  2. Tap Compress PDF to try the supported image settings for a 100 KB target. Some PDFs may remain above the limit.
  3. Download or share the new PDF, and check the size shown in the result.

Plan a 100,000-byte document budget

This preset uses 100 KB = 100,000 bytes. A four-page document has an average budget of 25,000 bytes per page before PDF overhead. That is an allocation example, not a promise that four scanned pages will fit. Small stamps, signatures and fine print can become hard to read at aggressive image settings.

Check text and signatures at this small size

The compressor re-encodes embedded images while retaining existing PDF text and vector content. Inspect scans at a useful zoom after downloading, especially names, reference numbers and signature strokes. A smaller file is not useful if the receiving office cannot read it.

If 100 KB is still too small

The result tells you whether the output meets 100,000 bytes or remains above the cap. Already compact text PDFs may have little removable image data. If the portal permits separate uploads, use Split PDF; otherwise keep required pages together and ask the receiving service which alternatives it accepts.

Frequently asked questions

Can a multi-page scan fit in 100 KB?

It depends on the scans and PDF overhead. Four pages leave an average of 25,000 bytes per page within 100,000 bytes, but legibility or the limit may still be impossible. Check the actual result rather than assuming a fixed page count.

Is 1 MB 1,000 KB or 1,024 KB?

Sites count it both ways. We use 1,000: a "1 MB" file here is at most 1,000,000 bytes, so it also passes a form that counts 1,048,576.

Is my PDF uploaded?

No. Everything happens in your browser on your own device.

Last reviewed: October 18, 2026

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