How to Use Compress PDF
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1. Upload Your PDF
Drag and drop a PDF file onto the drop zone, or click to browse and select it from your computer.
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2. Choose a Compression Level
Select Screen (maximum compression, ~72 DPI), eBook (balanced, ~150 DPI), or Printer (high quality, ~300 DPI) from the Quality dropdown.
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3. Compress and Download
Click 'Compress PDF & Download' and the tool will re-render each page in your browser and prompt you to save the smaller file.
The Technical Details
This interactive web utility provides fast, reliable, and completely private data transformations. In modern workflows, quick formatting, conversions, or estimations are essential. By running all logic entirely in your browser with client-side JavaScript, this tool guarantees that your data never leaves your machine. This approach delivers maximum performance and absolute data privacy, as no information is ever sent to a server.
Frequently Asked Questions
How much smaller will my PDF get?
Results vary by content. Image-heavy PDFs typically shrink 50–80% on Screen mode. Text-only PDFs see smaller reductions because text is already compact.
Does compression affect text quality?
No. Text, fonts, and vector graphics remain sharp at all compression levels. Only raster images are downscaled to the chosen DPI.
Is my PDF uploaded to a server?
No. The entire compression process runs in your browser using PDF.js and pdf-lib. Your file never leaves your device.
What is the maximum file size I can compress?
There is no hard limit imposed by the tool, but very large PDFs (hundreds of pages) may take longer to process depending on your device's memory and CPU.