Compress PDF

Reduce file size for email, WhatsApp, or uploading

Drop your PDF here

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Optimisation level

Ready after processing

Compress PDF files online — free, fast, and private

Large PDF files can be a hassle to email, upload to a job portal, or share on WhatsApp. PDFToolsFree lets you reduce PDF file size in seconds, directly in your browser. There is nothing to install, no account to create, and no watermark added to your document. Because the compression runs entirely on your own device, your files are never uploaded to a server — they stay completely private.

How to compress a PDF

  1. Click Select PDF or drag your file into the drop zone.
  2. Choose an optimisation level — Low for the best quality, Medium for a balanced result, or High for the smallest size.
  3. Press the Compress button and wait a moment while it processes.
  4. Click Download to save your smaller PDF.

Why use our PDF compressor

Frequently asked questions

How much can I reduce my PDF file size?

It depends on what your PDF contains. Documents with large or high-resolution images can often be reduced by 40–70%, while files that are mostly text are already small and may shrink only slightly. Try the High optimisation level for the maximum reduction.

Is it safe to compress confidential documents?

Yes. All compression happens locally in your browser using JavaScript. Your file is never uploaded to any server, so even sensitive contracts, bank statements, or ID documents stay completely private on your device.

Will compressing reduce the quality of my PDF?

The Low level keeps quality virtually identical. Medium and High trade a little image sharpness for a much smaller file. For documents you plan to print, choose Low or Medium; for email and online sharing, High is usually fine.

Is there a file size limit?

There is no fixed limit imposed by us. Because the work is done in your browser, very large files depend on your device's available memory, but typical documents of a few hundred pages compress without any issue.

Does it work on a phone?

Yes. The tool works in any modern mobile browser on Android and iOS — just tap Select PDF and pick a file from your phone.

Have questions? Visit our FAQ →