Sign a PDF on Mac and iPhone for Free

The current Mac path is the Show Markup Toolbar button, then the Sign button

The current article is titled “Fill out and sign PDF forms in Preview on Mac.” Its opening line says that in Preview you can add text and signatures to PDFs. The section “Create and use signatures” says you can capture your signature using your trackpad, the built-in camera on your Mac, or your iPhone or iPad. The steps say to go to the Preview app, open the PDF you want to sign, click the Show Markup Toolbar button if the Markup toolbar isn’t showing, then click the Sign button. An existing signature skips to step 6 on that page. The page addressed to macOS 26 prints that same capture section. The welcome page of the current guide is labeled “Preview User Guide for macOS 27.” This guide does not treat that label as the version installed on a particular Mac. The annotate article’s Sign row, checked the same day, says that if signatures are listed you click one and drag it, and that the blue handles resize it. To create a new signature, that row points to “Fill out and sign PDF forms in Preview.” The creation steps are the fill-out article.

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Trackpad, camera, and a nearby iPhone or iPad are three captures

Trackpad: click Trackpad, click the text as prompted, sign your name on the trackpad using your finger, press any key, then click Done. If you don’t like the results, click Clear and try again. If the Mac has a Force Touch trackpad, press more firmly to sign with a heavier, darker line. Camera: click Camera, hold the signature on white paper facing the camera so that it is level with the blue line in the window, and click Done when it appears. iPhone or iPad: click Select Device to choose a nearby device if more than one is available, sign with a finger or with Apple Pencil on iPad, then tap Done. Tap Clear on the device to try again. VoiceOver, which the page calls the built-in screen reader on Mac, can add a description before Done from the Description pop-up menu, such as Initials, or Custom. You then click the signature, drag it, and use the handles to adjust the size. If iCloud Drive is on, signatures are available on your other Macs that have iCloud Drive turned on. The Continuity note is one sentence: to use your iPhone or iPad to sign items, it must meet Continuity system requirements, and the page points to Continuity features and requirements for Apple devices. The sign page does not print that article’s device list. The Continuity article’s own section “Continuity Sketch and Continuity Markup” says you can use an iPhone or iPad to add sketches, shapes, and other markup to a Mac document and see the changes live on the Mac. The Preview sign note does not use the name Continuity Markup.

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Older Preview pages change Select Device, Done, and the Continuity note

The page addressed to macOS 15 prints the current capture steps, including a nearby device, tap Done, Continuity, and VoiceOver. The page addressed to macOS 14 begins “In the Preview app,” tells you to skip to step 4 for an existing signature, says Select Device chooses a device, and says tap Done. It has VoiceOver and does not have the Continuity note. macOS 13 adds “Click Create Signature if shown, then follow the onscreen instructions,” uses tap Done, then says to click the Sign button again and click the signature. macOS 12 says to follow the onscreen instructions, and its iPhone or iPad path says click Done. macOS 11’s device path also says click Done, and its opening line is that if a form requires a signature, you can add your signature to the PDF. macOS 10.15 says “Click iPhone or iPad,” then “when your signature appears in the window, click Done,” and its opening line says you can add your signature to any PDF. macOS 11, 12, and 13 do not print the Continuity note. The current page does not print “Create Signature if shown,” “Click iPhone or iPad,” or click Done on the device.

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On iPhone and iPad, Files is the prompt and Add Signature is the control

The current iPhone article is titled “Fill out forms, sign documents, and create signatures on iPhone.” Its version menu shows iOS 27 selected. The steps say to open the form or document, and, if prompted, to open the document in the Files app, then tap Save. To add beyond existing blank fields, tap the Add button. Add Signature: sign your name with your finger, then tap Done. The same bullet says you can also use Apple Pencil (USB-C) on iPhone Duo. Drag the signature where you want it. The current iPad article uses that Files prompt and says to sign with your finger or Apple Pencil, without the iPhone Duo sentence. When you are done, both pages say to tap the Menu button, then Export, Print, or the Share button. The iPhone sentence stops at sharing the completed document and then says to tap the Back button to save. The iPad sentence adds “using Mail, Messages, or AirDrop” before the Back button. The iPad page also prints “In iOS 27 and later, AutoFill suggestions appear above the keyboard as you type.” That sentence is on the AutoFill line. It is not the Add Signature bullet. The pages addressed to iOS 18 and iPadOS 18 start with “Go to the file you want to open,” then tap the file, then the same Files prompt. Their signature bullet says tap Done and drag. Their finish is the Share button, naming Mail, Messages, or AirDrop, then tap Done to close. They do not print the Menu button, Export, Print, or the Back button in that finish.

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Markup in Notes or Photos is a second section, with different resize words

The current iPhone and iPad pages both say that in supported apps such as Notes and Photos, you can use the Markup tools to add your signature to images and documents. Tap the Markup button or Markup. In the Markup toolbar, tap the Add button, then tap Add Signature. With the signature selected, drag it to move it, and drag any blue dot along its bounding box to resize it. A later section says the device saves the signature for the next time. On iPhone, sign with your finger, and a tip says to rotate the iPhone to have more space. The label control is the Menu button next to New Signature, with examples such as given name, nickname, or initials, and you tap the Done button to save and place it. The iPad page says to sign with your finger or Apple Pencil, and its Menu button is next to New Signature at the top of the popover. The version 18 pages say to drag any dot along the outline, to change line weight or color from the Markup toolbar, and to tap the More button for cut, copy, duplicate, share, or delete. Their new-signature label is the arrow next to New Signature, then tap Done. The current pages do not print that arrow or that More button in this section. Deleting on the current pages is Add or Remove Signature, then the Delete button next to the signature.

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Mail on iPhone, iPad, and Mac does not print the Preview Sign steps

The current iPhone Mail article says you can draw and write on a photo, video, or PDF attachment, then save it or send it back. Tap the attachment, tap the Markup button, draw with your finger, and you can also use Apple Pencil (USB-C) on iPhone Duo. Tap the Done button, then reply to the attachment sender, start a new message, save the annotated attachment to your files, or discard the edited attachment. The current iPad Mail article’s draw step says to draw with your finger, and the choice after markup is the More button, with the same four destinations, including save to your files. Neither article prints Add Signature, Trackpad, Camera, or Select Device. On the Mac, the Preview article’s section “Reply to an email with a PDF attachment” says to open the email, double-click the attachment so it opens in the Preview app, fill it out or sign it, then choose File > Save and select Reply to [Sender] or New Mail Message. If the PDF opens in a different app, that note says to close the file, Control-click the icon, choose Open With, then choose Preview. The current Mail on Mac article is a different window: while you are writing, move the pointer over a PDF you added, choose Markup, and its Sign row says that if signatures are listed you click one and drag it, using the blue handles to resize. To create a new signature, that row points to the Preview fill-out article. It does not repeat the trackpad, camera, or Select Device steps.

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A captured signature is not the certificate article

The Preview, iPhone, iPad, and Mail pages checked for the steps above tell you to capture a signature with a trackpad, a camera, a finger, or Apple Pencil, then place it. They do not use the word certificate, and they do not describe a check that the file has not been modified. The Keychain Access article “What’s a certificate?” says a certificate is usually restricted for particular uses, such as digital signatures, encryption, and use with web servers, and it calls that the key use restriction. The glossary entry addressed to macOS 10.13, titled “signed,” says a signed item has a certificate with a digital signature that confirms it originated from a trusted source. Its example is Mail checking that the message was created and signed by the individual who sent the certificate, and that the content hasn’t been modified or tampered with. That glossary entry is not the Sign button and not Add Signature. None of the pages checked names Adobe Acrobat Sign or gives steps for placing a certificate on a PDF. If the form asks for a certificate, or for a signature that confirms the file has not been modified, the capture steps in this guide are a different job. This guide does not name a product the checked pages do not name, and it does not report a test of another editor.

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Deleting a Preview signature reaches beyond the open PDF

On the current Preview page, deletion starts by opening a file, clicking the Show Markup Toolbar button if needed, clicking the Sign button, pointing at the signature, and clicking the X to the right. The signature is deleted from all apps that use Markup on that Mac. If iCloud Drive is on, it is also deleted from your other Macs that use iCloud Drive. The pages addressed to macOS 26 and macOS 15 say to open a PDF or image before that X. The pages addressed to macOS 11, 12, 13, and 14 print the X and the all-apps sentence without an “open a file” step. The page addressed to macOS 10.15 says to click the X to the right of the signature you want to delete, and it does not print the all-apps sentence. The iPhone and iPad deletion control is a different page: Add or Remove Signature, then the Delete button. This guide did not delete a signature on a Mac or an iPhone.

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Scope of this guide

We read the linked Apple Support pages on 28 October 2026 and wrote this guide from them. We did not install, run or time Preview, Files, Mail, or Markup, open a PDF, capture a signature, or save an output for this guide, and nothing here is a hands-on test result. Menus can differ by the macOS, iOS, or iPadOS version named on the guide page; check what your own screen shows. The pages checked do not display a separate price for Preview, Markup, Files, or Mail. This guide quotes the current pages and the pages addressed to macOS 10.15, 11, 12, 13, 14, 15, and 26, to iOS 18 and iPadOS 18, and to the macOS 10.13 glossary entry titled “signed.”