Other PDF Issues

How to Fix Acrobat PDF Highlighter Marking Multiple Lines

Emma Brown Oct 23, 2026 868 views

Question details

The user needs to know how to adjust the PDF highlighter tool when it inaccurately marks multiple lines or covers an incorrect vertical height instead of just the selected text.

How to Fix Acrobat PDF Highlighter Marking Multiple Lines

Product: Adobe Acrobat
Device & OS: not provided
Scenario: Attempting to highlight specific lines of text for annotation or review in a PDF document.
Observed behavior: The highlight area spans across multiple lines or extends abnormally high/low because it conforms to the irregular text structure or broken formatting of the PDF.

Before you start

Before troubleshooting, open a completely different PDF file and test the highlight tool to determine if the issue is isolated to your current document or a global application glitch.

Solution 1Recommended

Verify Document Integrity and Update Software

Determine if the highlighting error is specific to your current PDF's text layer and ensure your application is running the latest version.

There is no universal setting to adjust highlighter height. The tool relies directly on the font metrics and text layer structure embedded in the file. If the document was created with unusual line spacing or poor OCR, the highlight will reflect those errors.

Test an alternative file

Open a different, correctly formatted PDF document in your reader.

Apply the highlight

Select the text highlight tool and drag it across a sentence to see if the height issue persists.

Check document formatting

If the new document highlights correctly, the original file has a corrupted text structure. Try recreating, re-exporting, or re-running OCR on the original PDF.

Update your software

Navigate to 'Help' > 'Check for Updates' to ensure your application is running the latest version, which may resolve known rendering bugs.

Verify Document Integrity and Update Software

Document-Specific Issues: If the problem only happens in one file, the underlying text layer is likely broken. The visual text and the selectable text layer are misaligned.

Solution 2

Use the Rectangle Tool as a Highlighting Workaround

If the document's text structure is permanently corrupted and cannot be fixed, use a translucent shape to manually highlight areas.

Reliable PDF Highlighting

Highlight and Edit PDFs Seamlessly with WPS Office

If you are struggling with PDF formatting glitches in other readers, try WPS PDF. It accurately detects text layers for precise highlighting, commenting, and editing, ensuring your document review process is smooth and frustration-free.

1. Open your file: Launch WPS Office and open your problematic PDF document.
2. Access commenting tools: Click on the 'Comment' tab located in the top menu ribbon.
3. Select the Highlight tool: Click the 'Highlight' icon and select your preferred markup color.
4. Mark the text: Click and drag your cursor smoothly over the exact text you want to emphasize.

Precise text detection for accurate line-by-line highlightingFully compatible with standard Adobe PDF formatsLightweight, fast-loading PDF reader and editorFree built-in annotation, commenting, and markup tools

microsoft office alternative - wps office

Frequently Asked Questions

Is there a universal setting to adjust highlighter height in Acrobat?

No, there is no global setting to manually adjust the height of the text highlight tool. The height is automatically determined by the embedded font metrics, line spacing, and text structure of the specific PDF document.

Why does the highlighter tool select a whole block instead of one line?

This typically occurs if the PDF was generated from a scanned image with poor Optical Character Recognition (OCR), or if the document's text layer contains overlapping text boxes and unconventional formatting, causing the reader to misinterpret the line breaks.

How can I fix a PDF with a corrupted text layer?

You can try 'flattening' the document by printing it to a new PDF (using 'Print' > 'Microsoft Print to PDF'). After creating the flattened visual copy, run an OCR tool on the new file to rebuild a clean, correctly aligned, and highlightable text layer.

PDF Troubleshooting