What does Verify mode actually check?

It runs entirely in your browser and checks two things on a digitally-signed PDF: (1) the document content covered by the signature still hashes to the value recorded inside the signature, and (2) that record is itself validly signed by the signer's certificate key. Together these answer "has this been modified since signing?". It does NOT verify issuer trust — anyone can self-sign a PDF, so a valid integrity check is not proof of who the signer is. It reports the claimed signer name, certificate validity window, and signing time as separate, clearly-labelled (unverified) fields.

Can I add an APPROVED or CONFIDENTIAL stamp?

Yes — open the Stamp tab and pick from APPROVED, CONFIDENTIAL, DRAFT, or REVIEWED. Choose an ink colour, then set the page, position, and width like any signature. The stamp is rendered in your browser and embedded as a transparent image, so it prints and survives flattening.

How does the signature library work?

Your saved signatures are stored in this browser's localStorage only — they never leave your device. Use a private window or "Clear browsing data" to erase them. Library is limited to the 20 most recent signatures.

Can I sign multiple pages at once?

Run the tool once per page in v1. A multi-page UI is on the roadmap.

Where exactly is (x, y)?

Origin is the bottom-left of the page, units are PDF points (72 = 1 inch). x grows rightward, y grows upward. So y=72 is one inch from the bottom.

Why does my typed signature look plain?

The three included fonts (cursive / italic serif / bold sans) use system fallbacks so the tool works offline. For a more elaborate look, photograph a handwritten signature on white paper and use the Upload tab instead.

Can I sign a password-protected PDF?

No — unlock it first with Unlock PDF (you'll need the existing password), then sign it, then re-protect with Protect PDF if you still want a password. We refuse to silently strip encryption from a locked source, since signing is supposed to add provenance, not weaken access control.

Is the signature flattened into the page?

Yes — the signature is embedded as part of the page content stream (drawImage), not as a removable annotation. It survives re-saving, printing, and any downstream PDF tool that processes the file.

What does Verify mode actually check?

It runs entirely in your browser and checks two things on a digitally-signed PDF: (1) the document content covered by the signature still hashes to the value recorded inside the signature, and (2) that record is itself validly signed by the signer's certificate key. Together these answer "has this been modified since signing?". It does NOT verify issuer trust — anyone can self-sign a PDF, so a valid integrity check is not proof of who the signer is. It reports the claimed signer name, certificate validity window, and signing time as separate, clearly-labelled (unverified) fields.

Can I add an APPROVED or CONFIDENTIAL stamp?

Yes — open the Stamp tab and pick from APPROVED, CONFIDENTIAL, DRAFT, or REVIEWED. Choose an ink colour, then set the page, position, and width like any signature. The stamp is rendered in your browser and embedded as a transparent image, so it prints and survives flattening.

How does the signature library work?

Your saved signatures are stored in this browser's localStorage only — they never leave your device. Use a private window or "Clear browsing data" to erase them. Library is limited to the 20 most recent signatures.

Can I sign multiple pages at once?

Run the tool once per page in v1. A multi-page UI is on the roadmap.

Where exactly is (x, y)?

Origin is the bottom-left of the page, units are PDF points (72 = 1 inch). x grows rightward, y grows upward. So y=72 is one inch from the bottom.

Why does my typed signature look plain?

The three included fonts (cursive / italic serif / bold sans) use system fallbacks so the tool works offline. For a more elaborate look, photograph a handwritten signature on white paper and use the Upload tab instead.

Can I sign a password-protected PDF?

No — unlock it first with Unlock PDF (you'll need the existing password), then sign it, then re-protect with Protect PDF if you still want a password. We refuse to silently strip encryption from a locked source, since signing is supposed to add provenance, not weaken access control.

Is the signature flattened into the page?

Yes — the signature is embedded as part of the page content stream (drawImage), not as a removable annotation. It survives re-saving, printing, and any downstream PDF tool that processes the file.

Sign PDF

Add a signature to a PDF — type your name in a script font, upload a transparent PNG/JPG, or pick from your library. Or use Verify mode to check whether a digitally-signed PDF has been modified since signing.

Your files never leave your browser. All processing happens on your device — nothing is uploaded.

1. Upload your file

Drop a PDF file here

or click to browse

How does the Sign PDF work?

Add a signature to a PDF. Choose how to create the signature: Type your name and pick from 3 font variants for an instant signature; Upload a transparent PNG/JPG photo of your handwritten signature; or pick from Saved signatures kept in this browser only. Then drop the PDF you want to sign, set page + coordinates, and click. Coordinates are in PDF points (72 = 1 inch); the origin is the bottom-left of the page. For most documents, x=72, y=72, width=150 puts the signature in the lower-left corner. Everything runs in your browser — your PDF and signature image never leave your device. The signature is embedded as a real image — it prints, displays, and survives flattening.

🔒 Security & Privacy

All processing happens on your device. Your files never leave your browser, never touch our servers, and are not stored anywhere. Close the tab and the file is gone.

📱 Use it on any device

Works in any modern browser — Mac, Windows, Linux, iPhone, Android, and tablets. No installation, no app to download. Just open the page and start.

⚡ Quick & easy

Drag, drop, click. Most files process in seconds, not minutes. No watermarks added to your output, no per-day limits, and the tool always shows the result before asking you to download.

🎁 Always free, no signup

Free to use, every time. No account creation, no email required, no “trial” that converts to a paid plan. We make money from ads so you don’t have to pay.

Frequently asked

Sign mode is not — it places an image of your signature, like signing on paper. For PKI/cert-based digital signatures, use Adobe Acrobat or DocuSign. However, this tool now has a Verify mode that can cryptographically check a PDF that was already digitally signed elsewhere: it tells you whether the document has been modified since signing.