You can sign documents online using tools you probably already have on your device. Mac Preview, iPhone Markup, Microsoft Edge, and free web apps like PandaDoc all let you add a signature to a PDF without printing a single page. The method you choose depends on what device you’re using, how many documents you need to sign, and whether you need to send the document to others for their signatures too.
Sign on a Mac Using Preview
Every Mac includes Preview, which can add signatures to PDFs without any extra software. Open your PDF in Preview, click the Markup toolbar button (it looks like a pencil tip), then click the Signature icon. You’ll have three options for creating your signature: draw it on the trackpad with your finger, sign a piece of paper and hold it up to your camera, or sign on your iPhone if it’s nearby. Once you’ve created a signature, Preview saves it so you can reuse it on future documents.
After selecting your saved signature, click where you want it placed on the document, then drag the corners to resize it. Save the file, and you’re done. This works well for simple signing tasks where you’re the only person who needs to sign and you just need to return the completed PDF by email or upload.
Sign on Windows Using Microsoft Edge
If you’re on Windows, Microsoft Edge has a built-in PDF reader with inking tools that let you sign documents directly in the browser. Open any PDF in Edge, and you’ll see options to draw on the document. Select the pen tool, adjust the color and stroke width, and sign with your mouse, stylus, or touchscreen. It’s not as polished as a dedicated signature tool since there’s no way to save a reusable signature, but it works for quick one-off signing.
For a more reliable option on Windows, the free version of Adobe Acrobat Reader includes a “Fill & Sign” feature that lets you type, draw, or upload an image of your signature and save it for reuse across documents.
Sign on iPhone or iPad
Apple’s Markup tool is built into Mail, Files, and other apps across iOS and iPadOS. If someone emails you a document to sign, tap the attachment, then tap the Markup icon. Tap the plus button to add a signature. You’ll draw it with your finger or Apple Pencil, and the device saves it for future use. Place the signature where it belongs, tap Done, and send the email back.
You can also use Markup from the Files app. Open a PDF, tap the Markup icon, and follow the same process. This is handy when someone shares a document through a cloud service rather than email.
Sign on Android
Android doesn’t include a native signature tool in its default PDF viewer, so you’ll need an app. Adobe Fill & Sign (free on Google Play) is the most straightforward option. Open the app, select a document from your files or take a photo of a paper form, then tap the signature button to draw your signature. The app saves it so you can tap to place it on future documents. Once positioned and resized, use the share button to send the signed PDF however you need to.
Free Web Apps for Sending and Tracking
The built-in tools above work great when you just need to sign something yourself. But if you need to send a document for someone else to sign, or you want to track whether they’ve signed it, a dedicated e-signature platform is more practical.
PandaDoc offers a free plan that covers up to 60 documents per year with up to two recipients per document. You get a drag-and-drop editor, real-time tracking and notifications so you know when someone opens or signs your document, and a certificate of completion that records signer identity and timestamps. The free plan supports PDFs, Word documents, and image files. Limitations include email-only delivery (no shareable links), a cap of five templates, and no integrations with other software.
Other platforms like DocuSign and Dropbox Sign offer free trials or limited free tiers as well, though their free options tend to be more restrictive. If you only need to sign a handful of documents and don’t need workflow features, the built-in device tools or a free plan will cover you. If your needs grow beyond 60 documents a year or you need features like payment collection and multi-party signing workflows, paid plans from these platforms typically start around $10 to $15 per month.
Electronic Signatures vs. Digital Signatures
Most people searching for how to sign documents online need an electronic signature, which is simply any electronic indication of intent to sign. An image of your handwritten signature pasted into a PDF counts. So does typing your name into a signature field or drawing on a touchscreen.
A digital signature is a more specific, higher-security type of electronic signature. It uses encryption and a certificate from a trusted authority to verify both your identity and that the document hasn’t been altered after signing. Think of it as a tamper-proof seal. Digital signatures are typically required in regulated industries, government contracting, and international transactions. For signing a lease, an offer letter, a freelance contract, or a permission form, a standard electronic signature is what you need.
Are Online Signatures Legally Valid?
Yes. The federal ESIGN Act ensures that an electronic signature cannot be denied legal effect solely because it was executed electronically. Most states have also adopted the Uniform Electronic Transactions Act (UETA), which reinforces this at the state level. The legal requirements are straightforward:
- Intent to sign. All parties must intend to sign the document. This can be demonstrated by conduct, like clicking “I agree” or placing a signature in the designated field.
- Consent to do business electronically. The parties must agree to conduct the transaction electronically rather than on paper.
- Right to a paper copy. The signer must be informed of the option to receive the document in non-electronic form, and the right to withdraw consent.
- Record retention. The signed document must be stored in a way that accurately reproduces it for later reference.
There are a few exceptions. Wills, codicils, and testamentary trusts generally cannot be signed electronically under the UETA because they are unilateral documents rather than multiparty transactions. Court orders and certain family law documents may also require traditional signatures depending on your jurisdiction. For the vast majority of contracts, agreements, and business forms, an electronic signature is fully enforceable.
Tips for a Smooth Signing Process
Before signing, make sure you’re working with a PDF rather than a Word document or image file. PDFs preserve formatting and are universally accepted. If someone sends you a Word document to sign, most e-signature tools and even Preview on Mac will let you convert it first.
Create your signature once and save it in whatever tool you use most. Drawing a new signature every time introduces inconsistency and wastes time. If you use both a Mac and an iPhone, your saved signature in Markup syncs across devices through iCloud.
When you need a record of the signing, use a platform that generates a certificate of completion rather than just emailing a signed PDF back and forth. That certificate logs who signed, when, and from what device, which matters if the signature is ever questioned. Even free tools like PandaDoc include this on their no-cost plan.