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PDF Compressor

Reduce the file size of a PDF straight from your browser.

How to use PDF Compressor

  1. Upload the PDF you want to compress using the drop zone.
  2. Use the Image quality slider and the Target DPI buttons to choose how aggressive the compression should be.
  3. Click Compress PDF. When it finishes, review the before/after sizes and download the compressed file.

About PDF Compressor

The PDF Compressor rewrites the file through pdf-lib with compressed object streams, which already removes waste for many documents. If that is not enough, it can optionally re-encode any embedded raster images through your browser canvas at a lower quality/DPI, producing significantly smaller files for scanned or image-heavy PDFs.

All work happens on your device: the PDF is never sent to a server, the file name never leaves your browser tab, and the compressor works offline once the page has loaded.

Note: browser-side compression has limits. Pure-text, vector and already-optimised PDFs often shrink only a little. For those cases the result page will tell you honestly that a desktop tool may be needed.

Features

  • Browser-only processing — no files uploaded anywhere
  • Image quality slider (30% – 100%)
  • Target DPI presets from 72 up to 400 for aggressive flattening
  • Instant before/after size display with percentage saved

Frequently asked questions

Why did my PDF only shrink by 1%?

Text, forms and vector drawings are already very compact. Big compression wins happen when the PDF contains embedded photos or scans — those get re-encoded as JPG. For a text-only PDF a desktop compressor or linearized writer may do better.

Will the text in my PDF still be searchable and selectable?

If the resave path is used, yes. If the tool falls back to aggressive "flatten and re-embed" mode, every page becomes a single image and text is no longer selectable. A warning is shown when this happens.

Does the compressor work with password-protected PDFs?

Reader-password files are usually not loadable. Owner-password files (restrictions on print/copy but no open password) can be loaded because pdf-lib opens them in ignore-encryption mode, but please respect the document licence.

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