# 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. Only PDFs enabled for usage rights have the Place Signature option available.