LocalDocu

Compress PDF files without uploading them

Shrink PDF file size in your browser for email or forms. Balanced keeps text selectable; Maximum makes the smallest file. No upload, free, works offline.

Reduce PDF file size on your device. Select a PDF above, choose Balanced (keep selectable text) or Maximum (stronger shrink), pick a quality target, then compress and save locally.

Modes

  • Balanced — keeps text selectable where possible while reducing size.
  • Maximum — re-encodes pages as images for stronger size reduction.
  • Quality targets trade file size against visual fidelity.

Privacy

  • Compression runs entirely in your browser — nothing is uploaded to LocalDocu.
  • After the app shell is cached, supported compress workflows can continue offline.

On phones, prefer Balanced compression and smaller PDFs. Maximum mode needs more memory. Results download when native Save As is unavailable.

How to compress a PDF

  1. Select or drop a PDF on this page.
  2. Choose Balanced to keep text selectable, or Maximum for the smallest file.
  3. Pick a quality target, run Compress and save the smaller PDF on your device.

Compress PDF questions

How do I compress a PDF without uploading it?

Open Compress PDF in LocalDocu, select the file and run Compress. Compression happens inside your browser, so the document never leaves your device — useful for contracts, payslips, medical or ID documents.

What is the difference between Balanced and Maximum?

Balanced optimises images and structure while keeping text selectable and searchable. Maximum re-renders pages as images for a much smaller file, but text is no longer selectable.

How small will my PDF get?

It depends on the content. Scanned and image-heavy PDFs shrink the most; text-only PDFs are often already small. LocalDocu shows the before and after size so you can try another quality target.

Is there a file size limit?

In the browser, compression is limited to PDFs up to 40 MB per file to stay within device memory. Phones may need smaller files; Balanced mode uses less memory than Maximum.

Can I compress a PDF to send by email?

Yes. Most email services cap attachments at around 20–25 MB. Start with Balanced; if the file is still too large, use Maximum with a lower quality target.