Free PDF Compressor
Compress PDF files online, free — securely in your browser, nothing is uploaded anywhere.
Drag & drop a PDF here, or
How it works
- Pick a PDF — drag and drop it or browse from your device. It is opened directly in your browser, not uploaded.
- Compressed on your device — a WebAssembly build of Ghostscript re-encodes the file locally, in a background worker, at the quality preset you choose.
- Download the result — you get a new, smaller PDF. Your original file is never modified.
Private by design
Most online PDF compressors upload your document to their servers. Ours doesn’t — the entire compression engine runs inside your browser, so contracts, bank statements, ID scans and other sensitive documents never leave your machine. This is enforced by a Content-Security-Policy that blocks the page from talking to any third-party server, and it means the tool keeps working even if you go offline after the page loads. Read more in our privacy policy.
Frequently asked questions
Is this PDF compressor really free?
Yes — completely free, with no sign-up, no watermarks, and no daily limits. Because compression runs on your own device, it costs us almost nothing to offer, so there is no catch.
Are my PDF files uploaded to a server?
No. The compressor runs entirely in your browser using WebAssembly. Your file is read and processed in your browser's memory and is never transmitted anywhere. Our pages even ship a Content-Security-Policy that makes the browser block network requests to other origins, so this is enforced technically, not just promised.
Is there a file size limit?
There is no hard limit imposed by us. Practical limits depend on your device's memory — most laptops and phones handle PDFs of a few hundred megabytes comfortably.
How much smaller will my PDF get?
It depends on the content. Scanned documents and image-heavy PDFs often shrink by 50–90%. Choose from three quality presets: Screen (smallest, 72 dpi images), Ebook (balanced, 150 dpi) and Printer (high quality, 300 dpi).
Will compression reduce the quality of my PDF?
Text stays sharp — compression mainly re-encodes embedded images at a lower resolution. Pick the Printer preset if you need print-quality images, or Screen if smallest size matters most.
Is my original file changed or kept anywhere?
Your original file is untouched — you download a new, compressed copy. Nothing is retained after you close or reload the page.
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