PDF Editing Issues

Fix Acrobat Reader Markup and Underline Tools Not Working on iPad

Khadija Khan Oct 19, 2026 869 views

Question details

The user is unable to use the markup and underline tools in Adobe Acrobat Reader on an iPad, as the tools do not respond to Apple Pencil or touch input despite settings appearing correct.

Fix Acrobat Reader Markup and Underline Tools Not Working on iPad

Product: Adobe Acrobat Reader
Device & OS: iPadOS
Scenario: Attempting to annotate, draw, or underline text in a PDF document using an Apple Pencil or touch gestures on an iPad.
Observed behavior: The selected color and tool settings display normally, but drawing or underlining actions fail to register or produce any markings on the document.

Before you start

Ensure that your Apple Pencil is fully charged and securely paired with your iPad via Bluetooth, and verify that the specific PDF you are opening is not a scanned image that lacks selectable text.

Solution 1Recommended

Restart Devices and Update Acrobat Reader

Resolve temporary background glitches by restarting your iPad and ensuring your app is running the latest version.

Software bugs or temporary memory issues can cause Apple Pencil inputs to drop within specific applications. A quick restart and update often refresh these connections.

Force close the app

Swipe up from the bottom of your iPad screen to open the app switcher, find Adobe Acrobat Reader, and swipe up on the preview to close it.

Restart your iPad

Press and hold the top button and either volume button until the power off slider appears. Drag the slider, wait 30 seconds, and turn the device back on.

Update Acrobat Reader

Open the App Store, tap your profile icon at the top right, scroll down to check for pending updates, and tap 'Update' next to Adobe Acrobat Reader if available.

Update Apple Pencil firmware: Leaving your Apple Pencil attached to your iPad magnetically while connected to Wi-Fi will automatically install any pending firmware updates for the stylus.

Solution 2

Check Document Permissions and Security Restrictions

Determine if the markup issue is isolated to a specific document that has been locked or restricted by its author.

Solution 3

Sign Out and Reinstall Acrobat Reader

Clear corrupted app data or sync issues by re-authenticating your account and reinstalling the application.

Seamless PDF Markup with WPS Office

Annotate and Underline PDFs Easily on Your iPad

If Acrobat Reader continues to freeze or fail on your iPad, WPS Office provides a robust, built-in PDF editor. You can seamlessly use your Apple Pencil or touch input to highlight, underline, and draw on your documents without glitches.

1. Download WPS Office: Go to the App Store on your iPad, search for WPS Office, and download the free application.
2. Open your PDF document: Launch WPS Office, tap the 'Files' tab, and locate the PDF document you want to edit.
3. Access the annotation tools: Tap 'Edit' or the 'Annotation' tab at the top of the screen to reveal the extensive PDF markup toolbar.
4. Start marking up: Select the 'Underline', 'Highlight', or 'Pen' tool, customize your color preferences, and comfortably annotate using your Apple Pencil or finger.

Smooth Apple Pencil and touch input integration for precise document markupFully compatible with standard PDF formats and Microsoft Office files (Word, Excel, PowerPoint)Lightweight application that loads heavy PDF documents quicklyAll-in-one suite to manage documents, spreadsheets, presentations, and PDFs in one place

microsoft office alternative - wps office

Frequently Asked Questions

Why is my Apple Pencil not working in Acrobat Reader but works in other iPad apps?

This usually indicates a temporary software glitch specific to the Acrobat app rather than a hardware defect. Force closing the app, restarting your iPad, or un-pairing and re-pairing the Apple Pencil via your iPad's Bluetooth settings typically resolves the conflict.

How can I tell if a PDF is restricted from being marked up?

If a PDF has security restrictions, you will typically see a padlock icon or a 'Read-Only' label near the document title at the top of the screen. In these cases, markup, underline, and highlighting tools will be grayed out or unresponsive until the document is unlocked.

Do I need a paid Adobe subscription to underline text in Acrobat Reader on iPad?

No, basic markup tools like highlighting, underlining, and drawing are free to use in the mobile version of Acrobat Reader. If the tools are unresponsive, it is likely a software bug or a document restriction, not a subscription limitation.

Why is the underline tool drawing a line but not snapping to the text?

If the underline tool acts like a freehand pen instead of snapping to straight lines under text, the PDF may be a scanned image rather than a document with embedded, recognizable text. You may need to run Optical Character Recognition (OCR) on the document first.

PDF Troubleshooting