Quick answer
Sign PDF adds a drawn, typed, or image signature to any page of a PDF using the Evoke AI mobile app for Android and iOS. This produces a visible signature stamped onto the document, which is what most forms and agreements ask for. It is not a cryptographic digital signature, so it does not carry a certificate proving who signed or detecting later edits.
Electronic Signature vs Digital Signature
These two terms get used interchangeably and mean quite different things. Knowing which one you need takes thirty seconds and prevents a rejected document.
An electronic signature is a visible mark placed on the document — your drawn or typed name appearing on the signature line. This is what Sign PDF produces, and it is what the overwhelming majority of everyday documents ask for: rental agreements, permission slips, contractor invoices, school forms, NDAs.
A digital signature is a cryptographic certificate embedded in the file. It binds the document to a verified identity and breaks visibly if anyone edits the file afterwards. Some regulated contexts require this specifically — certain government filings, regulated financial documents, and formal notarised paperwork. If a form explicitly asks for a certificate-based or qualified signature, you need dedicated signing software with an issued certificate, not a stamped image.
Is a Drawn Signature Legally Valid?
In most jurisdictions, for most ordinary agreements, yes. Frameworks such as the ESIGN Act and UETA in the United States and eIDAS in the European Union generally recognise electronic signatures as valid, provided both parties intended to sign and consented to doing so electronically.
The common exceptions are wills, some property transfers, and certain family-law documents, which frequently still require wet ink or notarisation. This is general information rather than legal advice — if a document genuinely matters, confirm the requirement with whoever is receiving it before you sign.
Why Is This an App and Not a Web Tool?
Signing works far better with a touchscreen. Drawing a signature with a fingertip or stylus produces a natural line; drawing one with a mouse rarely does. Sign PDF is in the Evoke AI app because that is where the input method actually suits the task. Other PDF tools on this site — merge, split, compress, organize, protect — all run directly in your browser.
How to Sign a PDF
- Install the Evoke AI app from Google Play or the App Store.
- Open Sign PDF and load your document.
- Create your signature by drawing it, typing your name, or uploading an image of your handwritten signature.
- Place it on the correct page and resize it to fit the signature line.
- Export the signed PDF.
Getting a Clean Signature Image
If you upload a photograph of your handwritten signature rather than drawing it, the background is what usually goes wrong. A photo of paper carries a grey or yellow cast, so the signature arrives as a visible rectangle sitting on top of the document.
- Sign with a black pen on plain white paper, filling a good portion of the frame.
- Photograph it in bright, even, indirect light with no shadow across the page.
- Use the background remover on this site first to get a transparent PNG, then upload that.
- Drawing directly on the touchscreen avoids the problem entirely and is usually faster.
Practical Security Notes
- A stamped signature image can be copied out of a PDF by anyone who receives it. Only send signed documents to parties you trust.
- Flatten or password-protect the finished file if it will be circulated widely.
- Keep an unsigned master copy so you can re-issue the document without your signature embedded.
- A visible signature does not prevent later editing of the document. If tamper-evidence matters, you need a certificate-based signature.
Frequently Asked Questions
No. Sign PDF runs in the Evoke AI mobile app for Android and iOS, because drawing a signature needs a touchscreen. Merge, split, compress, organize, and protect PDF all run in your browser here.
Yes. It is free in the Evoke AI app and no watermark is added to your signed document.
For most everyday agreements in most jurisdictions, yes — electronic signatures are broadly recognised under laws such as ESIGN, UETA, and eIDAS. Wills, some property transfers, and certain family-law documents are common exceptions. Confirm with the recipient if the document is important.
No. It places a visible signature on the page. It does not embed a cryptographic certificate, so it cannot prove identity or detect later edits. If a form asks specifically for a certificate-based or qualified signature, use dedicated signing software.
Yes. Place the signature on each page that needs it, sizing it to the signature line in every location.
That box is the background of the photo you uploaded. Run the image through the background remover on this site to get a transparent PNG first, or draw the signature directly on your screen instead.