Compress PDF — reduce file size free

Reduce the size of a PDF by re-encoding its pages. Pick a quality level and download — everything stays on your device.

Drop a file here, or browse

Processed in your browser — nothing is uploaded.

🔒 100% free · your files never leave your browser

Make large files smaller with this free tool to compress PDF documents. Pick a compression level to shrink the PDF for email, upload or storage while keeping it readable.

NeuroScans compresses your PDF in the browser, so it’s never uploaded. This free PDF compressor has no sign-up and adds no watermark — your document stays private.

How to Compress PDF

  1. Upload the PDF you want to compress.
  2. Choose a compression level (strong, recommended or light).
  3. Click “Compress PDF”.
  4. Download the smaller PDF.

Why use NeuroScans Compress PDF?

  • Shrink large PDFs so they fit email and upload limits.
  • Pick strong, recommended or light compression.
  • Keeps documents readable while cutting file size.
  • No watermark and no sign-up required.
  • Compression runs in your browser — files stay private.

When to use this tool

Compressing a PDF helps when a file is too big to email, when a portal rejects large uploads, or when you want to save storage space. Choose a lighter level to preserve quality, or a stronger level when small size matters most.

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100% privateFiles are processed in your browser and never uploaded.
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Always freeNo subscription, no limits, no watermark on your output.
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No sign-upNo account or install — just open the tool and go.

Frequently asked questions

How do I compress a PDF to a smaller size?

Upload your PDF, pick a compression level, and click “Compress PDF”. A smaller version downloads instantly — free and watermark-free.

Will compressing reduce the quality of my PDF?

Stronger compression reduces image quality more. The “Recommended” level balances small size with good readability; choose “Light” to keep the best quality.

Is this PDF compressor free and private?

Yes. It’s completely free with no sign-up, and compression runs in your browser so your file is never uploaded.

How small can the PDF get?

It depends on the content — image-heavy PDFs shrink the most. Try the Recommended level first, then Strong if you need an even smaller file.

Why did my text-only PDF barely shrink?

Text PDFs are already compact, so there is little to compress. The biggest savings come from PDFs that contain large photos or scans.

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