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PDF Compressor

Data Stays on Your Device

Compress PDF files locally in your browser. Reduce file size cleanly without sending sensitive documents to external servers.

Click or Drag PDF file here

Supports all standard PDF documents. 100% private client-side processing.

What is the PDF Compressor?

The PDF Compressor reduces the file size of PDF documents in your browser, with quality controls that let you balance size against fidelity. Documents are processed locally and never uploaded.

PDF size is usually dominated by embedded images. A document of scanned pages or one containing high-resolution photographs can run to tens of megabytes, while the same document with sensibly compressed images is a fraction of that with no meaningful loss of legibility on screen.

Compression works primarily by re-encoding those embedded images at a lower resolution or quality. Text and vector graphics are already compact and are generally left as they are, which is why a text-only PDF compresses very little, there is nothing substantial to remove.

This is significant for privacy. PDFs are frequently contracts, invoices, medical records, and identity documents, and uploading them to a web service means handing that content to a third party. Processing in the browser avoids that entirely.

How to use the PDF Compressor

  1. Upload your PDF. Select or drag in the document. It is read into your browser and not transmitted.
  2. Choose a compression level. Higher compression means smaller files and lower image fidelity.
  3. Review the reduction. Compare the resulting size against the original before committing.
  4. Download the compressed file. The original document on your disk is unchanged.

Worked examples

What compresses and what does not

Expected results vary enormously depending on what the document contains.

Input
Scanned document, 20 pages   12 MB -> 1.8 MB
Report with photographs       8 MB -> 1.2 MB
Text-only document          400 KB -> 380 KB
Vector diagrams             600 KB -> 580 KB
Output
Image-heavy documents compress dramatically.
Text and vector content is already compact,
so there is little to remove.

Choosing a level

Match the setting to how the document will be used.

Input
Light:   minimal quality loss, modest reduction
Medium:  good balance, suitable for most uses
Strong:  significant reduction, visible softening
Output
Use Medium for email and web distribution.
Use Light when the document will be printed
or contains fine detail that must stay sharp.

Common use cases

  • Meeting email attachment limits. Most mail servers reject attachments above 20 to 25MB, and compression usually brings a document comfortably under.
  • Uploading to portals with size caps. Government and institutional forms frequently impose strict limits.
  • Reducing storage and bandwidth. Smaller documents in a shared drive or on a website cost less to store and serve.
  • Speeding up sharing. Compressed files upload and download noticeably faster on constrained connections.

Features and limitations

  • Processes entirely in your browser, the document is never uploaded.
  • Selectable compression levels with a before-and-after size comparison.
  • Preserves text, page structure, and document ordering.
  • The original file is untouched; you download a new compressed copy.
  • Documents consisting mostly of text or vector graphics compress very little, because there is no image data to reduce.

Frequently asked questions

Is my PDF uploaded to a server?

No. The document is read into your browser and processed locally, which matters a great deal given that PDFs often contain contracts, financial records, or personal information.

Will compression make my document unreadable?

At light and medium settings, text remains sharp because text is not re-encoded. Strong compression can visibly soften embedded images. Review the output before sending anything important.

Why did my PDF barely get smaller?

Because it is probably text or vector based, and already efficiently encoded. Compression works mainly by reducing embedded images, so a document without them has little to give.

Does compression affect text selection or searchability?

No. Text is preserved as text, so selecting, searching, and copying continue to work. Note that a scanned document has no text layer to begin with unless OCR was applied.

Is the original file modified?

No. The file on your disk is untouched, you download a separate compressed copy.

Can I compress a password-protected PDF?

Encrypted documents generally need to be unlocked first, since their content cannot be read for re-encoding while protection is in place.

All processing happens locally in your browser, your data never leaves your device.