PDF compression

Compress a PDF locally

CrabPDF can reduce PDF file size in the browser using local compression. Your PDF stays on your device, with no upload and no backend processing.

How it works

Open your PDF in CrabPDF.

Open the Compress panel in the right sidebar.

Choose Light, Medium, or Strong compression.

Apply compression and keep editing or download the result.

Compression levels

Light keeps more quality, Medium balances quality and size, and Strong aims for the smallest file. Results depend on the original PDF, especially embedded images.

Related tools

Merge PDFs · Reorder pages · Inspect PDFs · Protect with password

Privacy-first

Compression runs locally in your browser. Once CrabPDF is loaded, you can turn off Wi-Fi and keep working with cached tools.