How to fill out a
PDF form on Mac.

Fill out a PDF form in Preview

Download the PDF to your Mac first. In Finder, Control-click it and choose Open With → Preview. This makes sure you’re using Preview rather than the viewer inside your browser.

Before typing, choose File → Duplicate and work in that copy. Preview can save changes automatically. Making a duplicate first leaves you with a blank original if you need it again. Apple’s saving guide explains this behavior.

Now click a field, such as Name, and enter your answer. Press Tab to move between fields, and click any checkboxes you need. Work through all the pages; the last one is an easy place to miss a required date or signature.

If a field won’t accept text, move on to the text-box method below.

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Add text when the PDF isn’t fillable

A flat PDF contains the page’s text and artwork, but may have no interactive fields. A scanned PDF can be a picture of the entire page. You can still complete either one by placing text over the blanks, provided the document allows annotations.

Here’s how to add an answer in Preview:

1. Choose Tools → Annotate → Text.
2. Replace the text in the new box with your answer, then drag it into position.
3. Open the Markup toolbar and use Text Style to adjust the font, size, and color. Black text, sized close to the form’s own labels, usually looks right.

Use a separate text box for each answer. That makes it easier to move one address or date without disturbing everything else. For a printed checkbox, a small “X” may be enough, if the form’s instructions allow it.

These boxes are annotations sitting over the page. They don’t turn the document into an interactive form. If the recipient needs to collect actual field data from the PDF, ask for a fillable version.

Apple’s annotation guide covers the Text and Text Style controls.

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Add a signature

Once your answers are in place, click Show Markup Toolbar, then Sign. You can choose a signature you’ve already saved or create a new one using a trackpad, your Mac’s camera, or a supported iPhone or iPad. The available options depend on your devices.

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Follow the onscreen instructions, select the finished signature, and drag it onto the signing line. Use its handles to resize it. If the form asks for a date beside the signature, fill that in too.

Preview places a visual signature on the page. A certificate-based digital signature is different. If the sender asks for one, or requires a particular signing service, follow those instructions. Apple’s form-filling and signing guide covers the Preview controls.

Save the PDF, then reopen it

In the duplicate you’ve been editing, choose File → Save, or press ⌘S. When saving it for the first time, give it an obvious name, such as registration-completed.pdf, so you can tell it apart from the empty version.

Then close and reopen that saved file. Check for clipped answers, text sitting on top of labels, missed checkboxes, and anything left blank on later pages. Before attaching it, check that you’ve selected the completed copy.

Saving normally keeps Preview’s annotations editable. A flattened copy incorporates those annotations into the page, so you can no longer select an answer and move it as a separate text box. If you need one, choose File → Print → PDF → Save as PDF. Apple documents the difference in its annotation guide.

Keep an editable copy first. Flattening can remove interactive behavior, and it doesn’t make a document tamper-proof. Skip it when the recipient needs fillable fields or has specified a different submission method.

When a form still won’t work

Some PDFs need more than text boxes. The symptom usually tells you where to look:

• Editing is blocked. The PDF may have restrictions, or you may be working with a read-only file. Ask the sender for an editable copy or the necessary permissions. An annotation tool can’t bypass those restrictions.
• The page says “Please wait…” or content is missing. The form may use XFA or another feature your viewer doesn’t support. Download it and open it in the app the issuer recommends. The error page may be hiding the actual form.
• Totals or validation don’t update. Some forms use embedded scripts. Use the recommended reader and check the calculated values before submitting. Typing a total yourself may leave required validation unfinished.

If the sender specifically asks you to use Acrobat Reader, I’d follow that instruction. A PDF can look finished while still missing data that its submission process expects.

Filling forms with Blank

I built Blank for people who fill forms regularly. It helps you work through the fields, reuse details such as your name and address, and return to saved drafts. You’ll need macOS 26 or later.

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Open a PDF with File → Open PDFs…. Blank can use existing fields or suggest likely fields in flat and scanned PDFs. Review those suggestions; detection works best with English labels and straight printed lines or boxes, and it can miss things.

Fill in the answers and check any matches from your saved profile. For anything missing, use Add Text or Checkmark. Under Sign → Create Signature…, you can draw, type, or import a signature.

Before exporting, use File → Preview PDF to inspect the result. Then open the Export… menu, choose Editable PDF or Flattened PDF, and save the copy. Your draft stays in Blank and your original file stays untouched.

XFA forms, certificate-signed PDFs, and PDFs with editing restrictions open read-only. Blank doesn’t run embedded calculations or validation, and its signatures are visual signatures.

The trial includes three documents, with no watermark or card required. A document counts when you first successfully export or share it. You can keep editing and re-exporting those saved documents; a one-time Blank Pro purchase unlocks exports for more documents.

A few common questions