# Sign a PDF

Use a digital signature to indicate your approval. For best results, change your security preferences to always sign in Preview Document mode, so that you can view and sign the PDF in a secure state.

1. Click the signature field. Or, click Sign , and choose Sign Document.
2. Follow the on-screen instructions to apply your digital signature.

If the document does not contain an unsigned signature field, click Sign and choose Place Signature to sign the PDF.