PDF Editing Issues

How to Annotate and Edit PDFs on iPhone (Markup & Acrobat)

Natalie Taylor Oct 19, 2026 868 views

Question details

The user wants to know how to add text, highlight, and edit PDF files directly on an iPhone.

Product: iOS Files, Adobe Acrobat
Device & OS: iPhone 16 Pro / iPhone 16 Pro Max
Scenario: Reviewing and modifying PDF documents on a mobile device without needing a computer.
Observed behavior: The user is looking for built-in or third-party solutions to apply annotations and edits to a PDF file on iOS.

Before you start

Ensure your PDF file is saved locally on your iPhone or in iCloud Drive via the Files app so you can easily access it for editing.

Solution 1Recommended

Use the Built-In iOS Markup Tool

The quickest way to annotate PDFs without downloading third-party apps is using the native iOS Markup tool found inside the Files app.

Apple's built-in Markup feature provides essential annotation tools, allowing you to quickly sign documents, highlight text, draw shapes, and add text boxes without needing a dedicated PDF editor.

Open the Files App

Navigate to your home screen and open the native 'Files' app, then locate the PDF you want to edit.

View the PDF

Tap on the PDF document to open it in the built-in viewer.

Activate Markup

Tap the 'Markup' icon (which looks like a small pen tip) located at the bottom or top right corner of the screen.

Apply Annotations

Use the toolbar at the bottom to select a pen or highlighter. To add text or a signature, tap the '+' icon in the bottom right corner and select 'Text' or 'Signature'.

Save Changes

Once finished, tap 'Done' in the top-left corner to automatically save the annotations directly to the original file.

Editing Limitations: The built-in Markup tool is excellent for adding content on top of a PDF, but it cannot modify the existing, underlying text of the document.

Solution 2

Edit and Annotate using Adobe Acrobat Reader

For more advanced PDF commenting and editing options, you can use the Adobe Acrobat Reader app available on the App Store.

Edit PDFs Easily on iOS

Annotate and Edit PDFs on iPhone with WPS Office

WPS Office for iOS provides a powerful, free all-in-one PDF reader and editor. You can easily add text, highlight important sections, sign documents, and even convert PDFs to Word directly from your iPhone with an intuitive mobile interface.

1. Download WPS Office: Get the WPS Office app for free from the Apple App Store and launch it on your iPhone.
2. Open Your PDF: Tap on the 'Files' tab at the bottom to browse your local storage or cloud drives, and tap your PDF document to open it.
3. Access PDF Tools: Tap the 'Tools' icon at the bottom of the screen to reveal the PDF editing and annotation toolset.
4. Annotate the Document: Select 'Annotation' to use highlighters, pens, text insertion, and signature tools directly on the document pages.
5. Save Your Edits: Tap the 'Save' or 'Done' button in the upper left to secure your edits securely on your device or in the cloud.

Full compatibility with standard PDF and Microsoft Office formatsIntuitive mobile interface designed specifically for smooth iPhone and iPad annotationsEasily insert signatures, text boxes, and shapes without hassleAdvanced features to convert PDFs to Word, Excel, or PowerPoint on the go

microsoft office alternative - wps office

Frequently Asked Questions

Can I edit existing text in a PDF using the built-in iOS Markup?

No, the built-in iOS Markup tool only allows you to overlay new text, draw, and highlight over the document. To edit underlying existing text, you need a dedicated PDF editor app.

Where are my annotated PDFs saved on my iPhone?

If you use the built-in Files app, the changes you make using the Markup tool are saved directly to the original file's location, overwriting the unannotated version.

How do I add a signature to a PDF on my iPhone?

Using the iOS Markup tool in the Files app, tap the '+' icon in the bottom right corner and select 'Signature'. You can then draw a new signature with your finger or insert a previously saved signature into the document.

Is it completely free to edit PDFs on an iPhone?

Basic annotation tasks like highlighting, drawing, and adding text boxes are completely free using the built-in iOS tools or apps like WPS Office. Modifying existing core text often requires a premium subscription in many third-party apps.

PDF Troubleshooting