Compress PDF Files Online — Free, Fast, and Private

Compress PDF file
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Shrink any PDF, right in your browser.

Drop a file in, get back three compressed versions — light, medium, and strong — so you can pick the size that fits. Nothing is uploaded to a server.

Drop your PDF here, or browse
One file at a time · PDF only
Runs entirely on your device — your file never leaves this browser tab.
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Download your compressed files

Built with pdf.js and jsPDF, both free & open source. Note: pages are re-rendered as images, so scanned PDFs compress best; densely-typed text may look slightly softer at “Strong.”

Large PDFs are slow to email, slow to upload, and often get rejected outright by file-size limits. This free tool compresses PDF files right in your browser — no account, no waiting in an upload queue, and no copy of your file ever touches a server.

Drop in a PDF and choose how much to shrink it: a light touch that barely changes quality, a strong setting for scanned documents and image-heavy files, or a custom compression level if you want to dial in the exact balance yourself.

How to compress a PDF file

  1. Upload your PDF — drag and drop it in, or click to browse your files.
  2. Choose a compression level — Light, Medium, Strong, or set a custom percentage with the slider.
  3. Download your compressed file — compare the size reduction for each version and download the one that fits your needs.

Everything happens locally in your browser using open-source libraries (pdf.js, jsPDF, and pdf-lib). Your file is never uploaded anywhere, which means there’s no queue, no file-size cap imposed by a server, and nothing left behind afterward.

FAQs

Yes. There’s no sign-up, no watermark, and no limit on how many files you compress.

No. Compression happens entirely in your browser using JavaScript. Your file is never transmitted anywhere, which also means there’s no file-size limit imposed by a server — the only limit is your own device’s memory.

It depends on the level you choose. Light and Medium keep quality very close to the original. Strong applies more aggressive compression and is best suited to scanned documents or image-heavy PDFs rather than dense text. You can also use the Custom slider to choose your own balance between quality and file size.

If your PDF is mostly text and vector graphics, it’s often already efficient, and there isn’t much left to compress. In that case the tool automatically returns a structurally optimized version rather than forcing a re-rendered image version that would end up larger than the original.

There’s no hard limit, since nothing is uploaded to a server — but very large files (over ~40MB) will take longer and use more of your browser’s memory to process.

Yes — this is where compression makes the biggest difference. Scanned documents and image-heavy PDFs typically shrink the most, especially at the Medium or Strong settings.

Yes, the tool is fully responsive and works on any modern mobile browser.