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Compress your PDFs

Reduce the size of your PDF files without leaving your browser.

Drop your files here

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100% local processing, your files never leave your browser

Why compress a PDF in your browser

Most online PDF compressors upload your file to a server, run a compression pass and let you download the result. That model assumes you trust the operator with your contents and that the connection is fast both ways. With Filzy, the entire pipeline runs inside the same tab you opened: a Rust core compiled to WebAssembly re-encodes the JPEGs embedded in your PDF using libimagequant and an optimised JPEG encoder, while pdf-lib reassembles the document. Nothing leaves your machine, no temporary copies are kept anywhere, and the size reduction is the same you would get from server-based services like iLovePDF or Smallpdf, typically 40 to 80 percent on PDFs that contain photos or scanned pages.

Files stay on your device

Compression runs in a Web Worker. We never receive, log or cache your files. Closing the tab is the only cleanup needed.

Fast on your hardware

WebAssembly delivers near-native speed. A 50 MB scanned PDF typically compresses in 5 to 15 seconds on a modern laptop.

Three quality presets

Maximum (around 80% lighter), Balanced (around 60%), High quality (around 30%). Plus a manual JPEG slider for fine tuning.

How to compress a PDF with Filzy

  1. 1

    Drop your PDF

    Drag the file into the area above, or click to pick one. Several PDFs can be queued in the same batch.

  2. 2

    Pick a quality preset

    Maximum reduces aggressively for sharing, Balanced keeps text crisp, High quality is for archiving. The advanced JPEG slider lets you go deeper.

  3. 3

    Run the compression

    Filzy decodes embedded images, re-encodes them at the target quality and rebuilds the PDF in your browser. You get the new size and the percentage saved.

  4. 4

    Download or chain another tool

    Save the compressed PDF or send it straight to another Filzy tool, like sign or merge. Files transferred between tools also stay local.

Compress PDF, frequently asked questions