Question 1

Is pdf.sh really free?

Accepted Answer

Yes, 100% free forever. All 11 tools are completely free, even after you create an account. There are no premium tiers, no subscriptions, and no hidden fees. Guest users get 5 free compressions and 2 free digital signatures without signing up — these limits exist only to prevent abuse, not as a paywall. Sign up for free to unlock unlimited access.

Question 2

Why do I need to sign up for unlimited access?

Accepted Answer

The 5-action guest limit helps us prevent automated abuse of our service. Creating a free account removes this limit entirely — no payment required, no trial period. Just unlimited free access forever.

Question 3

Do I need to install any software?

Accepted Answer

No. pdf.sh works entirely in your web browser. There's nothing to download or install. Just open the website and start using the tools immediately.

Question 4

Do my files get uploaded to your servers?

Accepted Answer

It depends on the tool. 7 tools are 100% client-side (Merge, Split, Rotate, PDF to Image, Images to PDF, Watermark, Sign) — your files never leave your device. Compress PDF uses client-side WebAssembly by default, with server fallback only if your browser doesn't support it. Office to PDF and Password Protect require server processing.

Question 5

Is pdf.sh safe for sensitive documents?

Accepted Answer

Yes. For maximum privacy, use our client-side tools where files never leave your device. For server-processed tools, we use encrypted connections (HTTPS) and automatically delete files within 1 hour. We never store your passwords or access your file contents beyond what's needed for processing.

Question 6

What happens to my files after processing?

Accepted Answer

For client-side tools: Files exist only in your browser memory and are cleared when you close the tab. For server-side tools: Files are automatically deleted from our servers within 1 hour. We never keep copies.

Question 7

Which tools are 100% private (client-side)?

Accepted Answer

Merge PDF, Split PDF, Rotate PDF, PDF to Image, Images to PDF, Watermark PDF, and Sign PDF all process files entirely in your browser using pdf-lib or pdf.js. Your files never touch our servers.

Question 8

How much can I reduce my PDF file size?

Accepted Answer

Results vary depending on the PDF content. PDFs with many images typically see 50-90% size reduction. Text-heavy PDFs or already-optimized files may see smaller reductions. Use 'Maximum' compression for the smallest file size.

Question 9

Will compression affect print quality?

Accepted Answer

It depends on your compression level. 'Light' compression (300 DPI) maintains excellent print quality. 'Balanced' (150 DPI) is good for most uses. 'Maximum' (72 DPI) is optimized for screen viewing and email, not printing.

Question 10

Why is my PDF not getting smaller?

Accepted Answer

Some PDFs are already optimized and can't be compressed further. This often happens with PDFs exported from modern software. Our 'Smart Optimize' feature automatically retries with maximum compression if initial savings are minimal.

Question 11

When does compression use server processing?

Accepted Answer

Compression runs in your browser using WebAssembly by default. Server processing is only used when: (1) your browser doesn't support WebAssembly, (2) your browser doesn't support Web Workers, or (3) the file is too large for your device's memory.

Question 12

Is there a limit to how many PDFs I can merge?

Accepted Answer

There's no hard limit. You can merge as many PDFs as your browser's memory allows. For very large merges, we recommend processing in batches.

Question 13

What file formats can I convert to PDF?

Accepted Answer

Office to PDF supports Word (.doc, .docx), Excel (.xls, .xlsx), PowerPoint (.ppt, .pptx), and OpenDocument formats (.odt, .ods, .odp). Note that this tool requires server processing.

Question 14

Can I add a signature without printing?

Accepted Answer

Yes! Our Sign PDF tool lets you draw or upload your signature and place it directly on the PDF. No printing, scanning, or physical signing required. Processing happens entirely in your browser.

Question 15

How does password protection work?

Accepted Answer

Password Protect adds encryption to your PDF using strong AES encryption. You can set an 'open password' (required to view) and/or an 'owner password' (required to edit/print). Note: This requires server processing for secure encryption.

Question 16

What's the difference between 'Sign PDF' and 'Digitally Sign'?

Accepted Answer

Sign PDF adds a visual signature image to your document — great for informal use. Digitally Sign creates a legally binding cryptographic signature with an audit trail and timestamps, compliant with eSign laws (ESIGN Act, eIDAS). Use Digitally Sign for contracts, legal documents, and anything requiring legal validity.

Question 17

Are digital signatures legally binding?

Accepted Answer

Yes. Digital signatures created through our service comply with the ESIGN Act (US), eIDAS (EU), and other international e-signature laws. They include cryptographic verification, timestamps, and an audit trail that makes them legally equivalent to handwritten signatures.

Question 18

Why does digital signing require server processing?

Accepted Answer

Unlike visual signatures, digital signatures require server-side processing to create cryptographic signatures, generate audit certificates, and maintain the audit trail. Your documents are handled securely: encrypted in transit and automatically deleted after processing.

Question 19

Can I download a certificate after signing?

Accepted Answer

Yes! After signing is complete, you can download both the signed PDF and a separate audit certificate. The certificate contains the full audit trail including timestamps, signer information, and cryptographic verification details.

Question 20

Do I need to create an account to digitally sign?

Accepted Answer

Guest users get 2 free digital signatures. Sign up for a free account to unlock unlimited digital signatures — no payment required.

Question 21

What browsers are supported?

Accepted Answer

pdf.sh works on all modern browsers: Chrome, Firefox, Safari, and Edge. For compression, we recommend Chrome or Firefox for best WebAssembly performance. Mobile browsers are supported with adjusted file size limits.

Question 22

What's the maximum file size?

Accepted Answer

For client-side tools, the limit depends on your device's available memory. Desktop browsers typically handle files up to 50MB easily. Mobile devices may be limited to 10-20MB. Server-side tools can handle larger files.

Question 23

Why does compression take time?

Accepted Answer

PDF compression using Ghostscript WASM is computationally intensive. Processing happens entirely in your browser, so speed depends on your device. Larger files and higher compression levels take longer.

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