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OS Authority

Compress a PDF to under 500 KB

Try to fit a PDF below 500 KB while preserving readable document details. Photos and long scans may require stronger image compression or remain over the cap.

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 500 KB target. Some PDFs may remain above the limit.
  3. Download or share the new PDF, and check the size shown in the result.

Budget half a megabyte for several pages

500 KB here means 500,000 bytes. Five pages have an average allocation of 100,000 bytes per page before PDF overhead. This preset is useful when an upload form gives that exact limit; a document with many detailed photographs may need more space.

Compare photo detail with document legibility

The tool varies image size and JPEG quality, leaving existing text and vector content intact. Scan text and photographs respond differently: faces, diagrams and small labels may lose detail. Compare the output with your original and keep the original if the compressed copy is unsuitable.

Work with the actual result, not a predicted saving

The displayed result reports the encoded byte size and whether it is under 500,000 bytes. Files already below the cap are kept unchanged. If compression cannot meet the target, use the smallest result only where accepted; split a document only when the receiving form allows multiple files.

Frequently asked questions

Will photos inside the PDF still look good?

It depends on the number, detail and original compression of the photos. The tool may reduce image quality or dimensions to reach 500,000 bytes. Check the downloaded photos at a useful zoom; no particular visual quality is guaranteed.

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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