🔒 No server uploads · No watermark

Compress PDF online free

DukPdf lets you compress PDFs online for free, in your browser, with no server upload required. Pick a quality preset — lossless, balanced, or maximum — and the compression runs locally. No account required, no email, no watermark. Open the Compress PDF tool to start.

Open Compress PDF →

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A common scenario

You have a stack of image-heavy PDFs from a scanner and want to shrink each one for a shared team drive, without paying for a subscription.

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Why privacy matters here

Cloud compressors upload your PDFs to a remote server. DukPdf compresses in your browser, so your documents never leave your device. Read more on our private PDF editor page.

✓ No watermark✓ Works offline✓ Open DevTools to verify

How to compress pdf online free

Open the tool and add your file

Click the link below to open the tool in your browser. Drop in your PDF or click to select it. The file is read locally on your device.

Configure the operation

Pick a quality preset, page range, signature style, or whatever the tool needs. Every option runs in your browser — nothing is sent to a server.

Download the result

Click the action button. The result saves to your device. The original file is unchanged unless the tool explicitly modifies it.

Every step runs in your browser. No server uploads, no waiting.

Compress PDF online free — questions

Is the compress PDF online free tool really free?

Yes. Compression is free, with no account required, no email, and no watermark on the output. DukPdf Pro lifts file size and batch limits for users who need them.

How much can a PDF shrink?

Typically 20–60% for image-heavy scanned PDFs, less for text-only documents. The actual reduction depends on the original content — heavily scanned files with large images compress most.

Is the compression lossless?

You choose. Lossless mode keeps every pixel identical with modest size reduction. Balanced and maximum modes downsample images slightly for a much smaller file at near-identical visual quality.

Do the files get uploaded?

No. Compression runs entirely in your browser using qpdf compiled to WebAssembly. Open DevTools → Network tab while compressing — you will see zero upload requests.

🔒 DukPdf — YOUR FILES NEVER LEAVE YOUR DEVICE

Ready to compress pdf online free? Your files stay yours.

No server uploads. No watermark. Open the tool, drop your file, and download the result.