Sign PDFs and verify signatures

Use the eSign tab to place a handwritten-style signature, add stamps, sign with a digital certificate, and check documents you receive.

Requires Business edition or higher

Draw Signature, Certificate Signature and Verify Signature / QR need the Business edition. Load Signature and Stamp are available in every edition. Finalize Document needs the Pro edition.

Image signature or certificate signature

Farino PDF offers two kinds of signature. Choose the one that fits the document.

Create and place a signature

1. Open the PDF and go to the page you want to sign.
2. On the eSign tab, click Draw Signature. The Create your signature dialog opens.
3. Choose a method:
   • Type: enter your name in Your name, then pick a style: Classic, Formal or Personal. Each style uses a different script font.
   • Draw: draw with your mouse, pen or finger. Click Clear drawing to start over.
   • Image: choose a PNG, JPG or WebP file up to 20 MB. A transparent PNG works best.
4. Click Place signature. The signature appears on the current page.
5. Drag the signature to its position. Drag a corner handle to resize it. You can also drag it onto another page.
6. Click Apply Changes to write the signature into the PDF, then save the file.

Until you click Apply Changes, the signature stays an editable object. The Apply button at the right of the document tabs shows how many changes are waiting.

Use a saved signature image

If you keep a scanned signature as an image file, you can reuse it.

1. On the eSign tab, click Load Signature.
2. Choose a PNG or JPG file.
3. Click the page where the signature should go, then drag it into position.
4. Click Apply Changes.

Add a stamp

1. On the eSign tab, click Stamp.
2. Choose a stamp from the gallery, for example DISETUJUI, LUNAS, APPROVED, PAID or FINAL.
3. Click the page to place it.
4. Use Hand to move or resize the stamp, then click Apply Changes.

For more about stamps, see Comments and markup.

Sign with a certificate

A certificate signature needs a PKCS#12 file (.p12 or .pfx). This file holds your certificate and its private RSA key and is protected with a password. You get it from your certificate provider or your organization's IT team.

1. Make final edits to the PDF and save it first, because any later change breaks the signature.
2. Close open documents, then on the eSign tab click Certificate Signature.
3. Click Choose PDF… and select the PDF. Click Choose certificate… and select your .p12 or .pfx file. You can also drop both files onto the panel.
4. Type the Certificate password.
5. Click Open certificate. The panel shows the holder, issuer, validity dates and serial number. Signed by is filled with the name from the certificate.
6. Check Reason (the default is Document approval) and enter a Location if you like.
7. In Signature page, choose Last page or First page.
8. Keep Show a visible signature box on the page selected to add a box with "Digitally signed", the name, the reason and the date. Clear it for an invisible signature.
9. Click Sign Document.

Signing happens on your computer. Your certificate and password are not sent anywhere. The signed copy opens in a new tab. Save it without further edits.

Common messages:

• Couldn't open the certificate — check the password. The password is wrong, or the file has no matching RSA key and certificate.
• The certificate must be valid today. An expired certificate, or one that is not valid yet, cannot be used.
• If the PDF already contains a signature, signing stops and the file is left unchanged. Adding a second signature to a signed PDF is not supported.

Add a QR seal

Verify Signature / QR can stamp a QR seal so that recipients can check that a file was not altered.

1. Open the PDF and click Verify Signature / QR. The panel shows the Document fingerprint (SHA-256) of the current file. Click Copy fingerprint to copy it.
2. Fill in Document ID and Signed by.
3. In Verification page on your website, enter the address of your own verification page. The QR code opens this address with the document ID and a reference code.
4. In Stamp on, choose Last page only or Every page, and set the QR size (pt).
5. Click Add QR Seal.

The stamped PDF opens in a new tab. The panel shows the fingerprint of the final stamped file and a registration line. Register this fingerprint on your website so recipients can compare it.

Check a document you received

Open Verify Signature / QR with no document open to see the Verify a document you received section.

Compare with a fingerprint

1. Click Choose PDF… and select the file you received.
2. Paste the SHA-256 fingerprint you were given in Fingerprint you were given.
3. Click Check authenticity.

The result reads AUTHENTIC when the file matches byte for byte, or CHANGED when it does not.

Validate certificate signatures

1. Click Validate certificate signatures (Windows).
2. Choose the signed PDF.

For each signature, the result shows whether its integrity is valid, whether it covers the complete file or later changes exist, the certificate subject, and the Windows trust status. A file with only a QR code or a signature image shows that no certificate signature was found.

Finish the document

After signing, you can use Finalize Document on the eSign tab to add a FINAL watermark, flatten form fields and lock the file against editing. Finalize before you apply a certificate signature, because finalizing afterwards changes the file. See Redact and finalize.