For most people, the easiest way to sign a PDF is through a browser tool — open the website, upload the document, click where your signature goes, type or draw it, download the signed file. No printing, no scanning, no app to install. The whole thing takes under two minutes.
Browser-Based Signing: Works on Any Device
WukongPDF's Sign PDF tool runs in any browser — Chrome, Safari, Edge, Firefox — on desktop or mobile. Upload the PDF, click the signature tool, and you get three options: type your name in a signature-style font, draw your signature with a mouse or finger, or upload a photo of your handwritten signature. Position it on the page, resize if needed, and download. The signed file is ready to send.
Drawing with a finger on a phone touchscreen actually produces a reasonably natural-looking signature. On a laptop trackpad it's more awkward, so typing or uploading a signature image tends to look cleaner for desktop users.
On Mac: Preview Is Already There
Mac users don't need to open a browser at all. Open the PDF in Preview, click the Markup toolbar button (the pen-tip icon), and select the signature tool — it looks like a cursive S. Preview lets you create a signature by drawing on the trackpad, signing a piece of white paper and holding it up to the camera (it captures the signature shape), or using an iPhone or iPad nearby if it's within range.
Signatures created in Preview are saved for reuse — sign once, and it's available for every future document. Click the signature tool, select your saved signature, click where it should go, and it drops into place. Once positioned, use File → Export as PDF to save the signed version.
On iPhone: Use Markup in Files or Mail
On iPhone, open the PDF in the Files app and tap the Markup pen icon to enter annotation mode. The signature tool is in the toolbar at the bottom. You draw your signature with your finger, and it's saved for future use. Tap where you want it placed, resize if needed, and save. From Files, tap the Share button to send the signed PDF by email, AirDrop, or anywhere else.
Save Your Signature as an Image for Reuse
If you sign documents regularly, having your signature saved as a PNG file with a transparent background saves time across every signing method. Sign your name with a black marker on white paper, photograph it in good lighting, crop it tightly, and save it to your phone's photo library or your computer's documents folder.
When you need to sign anything, you just upload that image and place it. It takes about five seconds instead of drawing your signature fresh each time, and it looks consistent across every document — which matters more than most people realize when contracts and agreements are involved.
Is an Electronic Signature Legally Valid?
For the vast majority of business contracts, NDAs, offer letters, vendor agreements, and freelance contracts — yes. In the US, the ESIGN Act gives electronic signatures the same legal standing as handwritten ones for most document types. The EU, UK, Australia, and most other countries have equivalent laws. Exceptions exist (some real estate transactions, certain court filings, wills in some jurisdictions), but for everyday business use, a typed or drawn electronic signature is fully enforceable.