How to Sign a PDF on Mac
A quick free way to sign a PDF on a Mac is Preview: choose Tools > Annotate > Signature, create your signature with the trackpad, the camera or an iPhone or iPad, and click it to place it on the page. File Acture's Edit & Sign PDF does the same with a typed, drawn or image signature plus the date and your name, and saves a new copy without uploading anything.
Updated September 30, 20267 min read
By the File Acture team
A rental contract, a school form or an invoice approval reaches you as a PDF, and all it needs is your signature. Printing it, signing with a pen and scanning it again still works, but a Mac can do the whole job in a minute without paper.
This guide starts with Preview, which is free and already on your Mac, then shows what File Acture's editor adds. It also explains what kind of signature this is, because some recipients ask for more than a visible signature.
Can you sign a PDF on a Mac for free?
Yes. Preview, the app that opens PDFs on every Mac, can sign them, and for most forms and letters it is all you need. Open the PDF, choose Tools > Annotate > Signature (or use the signature button in the Markup toolbar) and create your signature in one of three ways:
- Trackpad: sign with a finger on the trackpad.
- Camera: sign a white sheet of paper with a dark pen and hold it up to the Mac's camera.
- iPad or iPhone: draw the signature on the screen of a nearby iPad or iPhone.
How do you place the signature, and does Preview change the original?
Click the signature to put it on the page, drag it onto the signature line and resize it by its corners. Preview keeps the signature for next time, so the second document takes one click. It writes the change into the file you opened, so work on a copy if you need the unsigned original.
How do you add a signature to a PDF with File Acture?
Choose File Acture when you would rather type your name in a signature font than draw it with a finger, when you keep your signature as a scanned image, or when the same PDF also needs a correction. In the editor, the Signature button opens the Add Signature & Stamp window, which offers three ways to make a signature:
- Type (Keyboard): type your name, pick one of the signature fonts (each one previews your name) and an ink color: navy, black, burgundy or a custom one.
- Draw (Trackpad): sign on the white canvas with the trackpad or mouse. Clear Drawing starts over, and the signature is placed with a transparent background.
- Image / Stamp: drop an image of your signature or stamp on the window, or pick a file with the Choose Image... button. PNG, JPG, HEIC and TIFF files work, and so does a scanned signature; the original colors and transparency are kept.
How do you place, resize and save it?
Click Insert Signature (Add Image / Stamp for a picture) and the signature lands on the page you are viewing. Drag it onto the signature line, pull the handle at its bottom-right corner to resize it, and press Delete to remove it if you want to start again. Use Add Text for the date or your printed name; if the document itself has a wrong date or name, change the printed text in the same editor.
Save PDF (Command-S) asks where to put the copy and suggests the original name with “-edited” added. The original file stays as it was. To sign another page, go to it and insert the signature again; each copy moves and resizes on its own.
Is a signature added this way a real digital signature?
No. Preview and File Acture both add a visible signature to the page: a drawing, a picture or, in File Acture, a typed name. It looks like a signature and works for forms that only ask for one, but it is not a certificate-based digital signature: nothing in the file proves who placed it or shows whether the document was changed afterwards.
Some contracts, banks and government portals ask for a certified digital signature or for a specific electronic signature service. Rules differ by country and by document, and this guide is not legal advice, so check which type of signature the recipient accepts before you sign.
How do you make a signature image that looks natural?
If you will reuse one signature, make the image once and keep it. A few habits make it look like ink on the page instead of a pasted box.
- Plain paper, dark pen. Sign on white paper with a black or dark blue pen, in even light and without shadows.
- Straight-on and tight. Photograph or scan it square-on and crop close to the ink.
- A transparent PNG if you can. Remove the white background in an image editor and save the result as a PNG, so the signature does not cover the line or text behind it. A JPG works too, but its white rectangle shows.
- Keep the file private. A clean image of your signature is easy to misuse, so don't leave it in shared folders or send it around.
Is it safe to sign a PDF online?
Online signing tools work on a copy of your document on their servers, and some ask for a scan of your signature too. For a lease, a payslip or an ID copy, that is a poor fit. File Acture signs the PDF on your Mac and never uploads it or the signature image. To count free runs it sends only the tool's name and two anonymous identifiers, never file names or contents.
The free version includes 3 runs on each Mac, and saving a signed PDF counts as one run; for unlimited use, see pricing. If the document is sensitive, protect it with a password before you send it, and if it contains details that must not be seen, redact them for good first.
How to sign a PDF on a Mac with File Acture
- 1
Open the PDF in the editor
Choose Edit & Sign PDF in the sidebar, add your PDF with Choose Files… or by dragging it in, then click Open Editor.
- 2
Go to the page and click Signature
Scroll to the page that needs your signature and click Signature.
- 3
Type, draw or choose your signature
In the Add Signature & Stamp window, pick Type (Keyboard), Draw (Trackpad) or Image / Stamp, then type your name, sign on the canvas or drop an image of your signature.
- 4
Place it and size it
Click Insert Signature (Add Image / Stamp for a picture), drag the signature onto the signature line and pull its bottom-right handle to resize it. Use Add Text for the date or your name.
- 5
Save a new copy
Click Save PDF (Command-S) and choose where to save. The original PDF stays unchanged.
Type, draw or place your signature on a PDF, right on your Mac.
Free to try · runs on your device
| Method | Signature you can add | Uploads the file | Kind of signature |
|---|---|---|---|
| Preview | Drawn on the trackpad, scanned with the camera or drawn on an iPad or iPhone | No | Visible signature |
| File Acture Edit & Sign PDF | Typed, drawn or from an image, plus date and name text | No | Visible signature |
| Online signing site | Depends on the site | Yes | Visible or certificate-based, depending on the service |
| Certificate-based digital signature | Issued by a certificate authority or a signing service | Depends on the service | Shows who signed and whether the file changed |
Questions
Can I sign a PDF on a Mac for free?
Yes. Preview is free and already installed. File Acture's editor is free to try as well: the free version includes 3 runs on each Mac, and each saved PDF uses one.
Can I use a photo of my signature?
Yes. Sign on white paper, photograph or scan it, and add the image in File Acture with Image / Stamp. A PNG with a transparent background looks most natural, and Preview can also capture a signature from the camera.
Is a signature added this way legally binding?
That depends on the country, the document and who receives it, and this guide is not legal advice. What you add is a visible signature, not a certificate-based digital signature, so ask the recipient which kind they accept.
Can I add the date next to my signature?
Yes. In File Acture's editor, use Add Text to place the date or your printed name anywhere on the page and drag the box into position. Preview has a text tool for the same job.
Can I put my signature on more than one page?
Yes. In File Acture, go to each page and insert the signature again; every copy moves and resizes on its own.
Does signing change or upload my original PDF?
No. File Acture saves the signed PDF as a new copy and leaves the original unchanged, and nothing is uploaded. Preview writes into the file you opened, so work on a copy there.