How to Fill Out a PDF Form on Mac

Tax returns, NDAs, rental applications, onboarding paperwork. At some point, a PDF form lands in your Downloads folder and needs to go back completed. How you do this depends on the type of form you're dealing with.

Some PDFs have interactive fields built in. You click a box and your cursor appears. Others are flat, or scanned, with no fields underneath at all. Learn how to tackle both on a Mac, and what to do when a form refuses to cooperate.

The fastest, no-hassle way to fill out an interactive PDF on Mac is a browser-based PDF Form Filler. It works in Safari, Chrome, or Firefox. No software to install, and no plugins needed.

1. Upload Your PDF to the Form Filler

• Go to the PDF Form Filler in your browser.

• Upload your PDF from your Mac.

• You can also pull files in from Google Drive, Dropbox, or OneDrive.

No sign-up needed.

Start here: Use the form filler below to upload your PDF and start filling it on your Mac.

2. Click Each Field and Enter Your Details

• Click any text field. When your cursor appears, you can start typing immediately.

• Tab through the form to move between fields in order.

• Tick checkboxes with a single click.

• Dropdowns open on click. Select your option and move on.

3. Download the Completed Form

• Click to “Download” once you've filled everything in.

• The PDF saves to your Mac with all your entries in place.

Formatting, fonts, and layout stay exactly as they were in the original.

Flat PDFs look like regular PDFs but behave like images. Clicking on them does nothing because there are no fields underneath. You'll run into them with scanned documents, older PDFs, and any PDF that was created in Word or by printing to PDF. A PDF must be created with fillable fields to be interactive.

The fix is to add your text directly on top of the page.

1. Upload the Flat PDF

• Go to our PDF Form Filler in any browser.

• Upload your flat PDF by clicking “Choose Files” or dragging it in.

The tool detects there are no interactive fields and switches to annotation mode.

2. Position Text Over the Form Fields

• Click the “Add text” button to place a text box on the page.

• Click and drag it to sit over whichever field you're filling in.

• Type your answer, then resize or adjust the font if needed so it fits the space cleanly.

• Add a new text box for each field. Work through the form section by section.

3. Add a Signature if Required

If the form needs a signature at the end:

• Click on the “Signatures & initials” button.

• Draw with your trackpad, type your name, or upload an image of your signature.

• Drag it over the signature line.

4. Download the Finished PDF

• Click to download your completed document.

• It saves as a standalone PDF, separate from the original.

Preview is Apple’s built-in PDF app on Mac. Double-click a PDF and it opens in Preview automatically. The Markup toolbar lets you add text annotations and signatures, and macOS 26 introduced a small refresh that makes those tools easier to use.

It's a good fit for quick jobs—adding your name and date to a short form or signing a document before you send it back.

1. Open the PDF in Preview

• Double-click the PDF in Finder to open it in Preview.

• If it opens in a different app, right-click the file, choose “Open With,” and select “Preview.”

2. Show the Markup Toolbar

• Click the pencil icon in the top-right area of the toolbar.

• The Markup toolbar appears below the main toolbar, with text and annotation tools.

• Alternatively, go to “View” and select “Show Markup Toolbar” from the menu bar.

3. Add Text to the Form

• Click the text tool in the Markup toolbar.

• Click anywhere on the PDF page. A text box will appear.

• Type your answer, then click outside the box to deselect it.

• Reposition the box by clicking and dragging it over the correct field.

• Repeat for each field that needs filling in.

You can adjust the font, size, or color by selecting the text and then clicking on the “Text Style” button in the Markup toolbar.

4. Add Your Signature

• Click the signature icon in the Markup toolbar (it looks like a cursive signature).

• If you've saved a signature before, select it from the list.

• To create a new one, click “Create Signature,” then sign on your trackpad, use your iPhone or iPad as a drawing surface, or hold a physical signature up to your Mac's camera.

• Once added, drag the signature to sit over the signature line and resize as needed.

5. Save the Completed PDF

Preview saves changes automatically as you work. To be safe, create a copy of the original before you start.

• Press Cmd+S to save or go to “File” and choose “Duplicate” if you want to save a separate copy.

• To share the completed form, go to “File” and choose “Share” or drag the file from Finder into an email or message.

A few common reasons why your PDF isn’t behaving as you expected include:

• The form is flat or scanned. What looks like form fields are no different to an image if the PDF is scanned or flat. Use the text tool in PDF Form Filler to add your answers on top of the page.

• The PDF is password-protected. If the document has been locked against editing, you won’t be able to add anything. If you have the password, Smallpdf's Unlock PDF tool can remove the restriction.

• The fields are locked by the creator. This happens with finalized official documents. No tool can override a deliberate read-only lock set by the author.

Smallpdf is free to use, with some limitations. If you deal with PDFs daily or need to work with several forms at once, Pro unlocks higher limits and batch processing. And it comes with a 7-day free trial.