Compress PDF Online — Free, Private, In Your Browser

QuietPDF is a free online PDF compressor that runs entirely in your browser. Drop in one PDF or many, pick a compression level, and download smaller PDFs in seconds — no signup, no server uploads, no watermarks. Your files never leave your device. That’s the whole idea.

Why compress PDFs with QuietPDF

• 100% private

  Files are compressed in your browser. Nothing is uploaded to a server, ever.

• Batch compression

  Drop multiple PDFs at once and download each one individually — or all of them with one click.

• Three quality presets

  Lossless for archives, Balanced for everyday docs, Extreme for email-attachment limits.

• Fast & offline-friendly

  Once loaded, the page works offline. WebAssembly does the heavy lifting on your own CPU.

• No watermarks, no signup

  Output PDFs are clean — same content, smaller size. No accounts, no email needed.

• Local vault

  Recent compressions live in your browser’s IndexedDB for 2 hours, then auto-clear. Wipe early any time.

How to compress a PDF online

1. 1

   Drop your PDFs

   Drag one PDF or many onto the upload zone, or click to browse.

2. 2

   Pick a preset

   Choose Lossless, Balanced, or Extreme — applied to every file in the batch.

3. 3

   Download

   Compressed PDFs are ready in seconds. Download each one, or all at once.

Frequently asked questions

How do I compress a PDF online for free?

Drag your PDF onto QuietPDF (or pick several at once), choose a compression level — Lossless, Balanced, or Extreme — and click Compress. The compressed file downloads to your device. The whole process runs in your browser, so there are no server uploads and no signup required.

Is QuietPDF free to use?

Yes. QuietPDF is 100% free, with no signup, no watermarks, no daily limits, and no email harvesting. Compress as many PDFs as you want.

Is it safe to compress my PDFs here?

Yes. Your files never leave your browser tab. Compression happens locally on your device using WebAssembly. We can’t see your PDFs, store them, or send them anywhere, because there is no server-side processing involved. That’s the whole point of QuietPDF.

Can I compress multiple PDFs at once?

Yes. Drop several PDFs into the upload zone and QuietPDF will compress them one by one (to stay gentle on your browser’s memory). When the batch is done you can download each PDF individually, or hit "Download All" to grab the whole set.

What’s the difference between Lossless, Balanced, and Extreme?

Lossless preserves perfect image quality and only strips redundant metadata. Balanced downsamples embedded images to 150 DPI at 80% quality — best overall savings for everyday documents. Extreme pushes images to 90 DPI at 50% quality for the smallest possible files (great for email attachment limits).

Does QuietPDF work offline?

Once the page has loaded, yes. Compression runs entirely in your browser — you can disconnect from the internet and the tool will still work.

Does QuietPDF add a watermark to compressed PDFs?

No. Compressed PDFs come out clean — same content, smaller size. No watermark, no branding stamped on your file.

How much can QuietPDF reduce a PDF’s size?

It depends on the document. PDFs that are mostly text or vector graphics may shrink modestly. PDFs full of scanned pages, screenshots, or photos can typically be reduced by 50–80% with the Balanced preset, and even more with Extreme.

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