A touch screen is convenient for drawing a signature, but placement and scale matter more on a small display. Zoom the page, position the signature inside the intended field and review the saved PDF before sending it.
A visual signature placed on a page is not the same as a certificate-based digital signature with cryptographic validation. Confirm what the recipient requires.
Prepare on your phone
Open Sign PDF in a current browser, choose the file from device storage or cloud storage, and create a drawn, typed or uploaded signature. Use a clean signature image with a transparent background if uploading one.
Place it accurately
Tap to add the signature, then drag it to the correct page and use the corner handles to resize it. Keep the entire selection inside the page boundary. Zoom in before final placement so it does not cover a date, name or form line.
Save and verify
Apply the signature, download the result, and reopen the actual downloaded file. Confirm the correct page was signed and that the mark is neither cropped nor blurry. If the document needs identity verification or tamper evidence, use an approved digital-signature service instead of a visual mark alone.