Compress PDF Online — Reduce File Size Free

Shrink your PDF files without losing quality. Works entirely in your browser — no uploads, completely private.

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Compressing…

Optimizing…

Compression Complete!

Your compressed PDF is ready.

How to Compress a PDF File Without Losing Quality

Large PDF files are a common headache. Email attachments bounce back. Cloud storage fills up. Website uploads fail. Our free online PDF compressor solves all these problems by stripping away unnecessary data and rebuilding the file structure more efficiently — without affecting what you see on screen.

What Does PDF Compression Actually Do?

PDF compression works by removing redundant metadata, optimising internal object streams, and cleaning up leftover data from previous edits. The visual content of your pages remains completely intact. In many cases, compression reduces file size by 20–60% depending on how the original file was created.

When Should You Compress a PDF?

  • Before emailing — most email services limit attachments to 10–25MB
  • Before uploading to government portals, job sites, or university systems
  • When storing large archives of documents to save disk space
  • Before sharing on WhatsApp, Telegram, or other messaging platforms
  • When embedding PDFs on websites to improve page load speed

Does Compression Affect Text or Image Quality?

Our structural compression method does not re-encode images or alter text. The output PDF looks identical to the original. If you need more aggressive compression (which may slightly reduce image resolution), we recommend combining this tool with our Grayscale PDF tool for black-and-white documents.

FAQs — Compress PDF

Why is my compressed file larger than the original?
Some PDFs are already optimally compressed. In these cases, our tool will report the file as "already optimized" and the output may be similar in size. This is normal and means the original file was already efficient.
Can I compress a scanned PDF?
Yes, though scanned PDFs consist mainly of embedded images, so structural compression has limited effect. For heavy reduction of scanned documents, converting to grayscale first can help significantly.
Is there a limit to how many times I can compress a PDF?
No limits — use the tool as many times as you like, completely free. However, compressing an already-compressed PDF won't reduce it further.