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How to Highlight a PDF on iPhone

Open the PDF, choose Highlight in the markup tools, mark the passage another person needs to see, and export a reviewed copy without printing the document.

Short answer

Import the PDF into ScanLens, open Markup, select Highlight, choose a readable color and size, draw over the intended passage, inspect the result, and export a separate copy.

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How do you highlight text in a PDF on iPhone?

Open or import the PDF, enter the markup tools, choose Highlight, and mark only the words or rows the recipient needs to notice. Use a translucent color that keeps the text readable, then inspect the page and export a separate annotated copy.

Highlighting adds visual emphasis. It does not change the underlying wording, create a comment thread, prove approval, or hide confidential information. Use a stamp, signature, or verified redaction workflow when the task is different.

Step by step: highlight a PDF passage on iPhone

  1. Import the correct file. Confirm the PDF version and page count before marking a passage in a contract, article, form, or report.
  2. Open Markup and select Highlight. Choose the dedicated highlight tool rather than an opaque marker when the text must remain readable.
  3. Set a readable color and size. Use enough contrast to make the passage visible without obscuring letters or depending on color alone for meaning.
  4. Mark the exact passage. Zoom in and avoid extending the highlight into neighboring totals, dates, clauses, or form fields.
  5. Review the full page. Check the mark at normal reading size and confirm that it points to the intended content.
  6. Export a separate copy. Keep the original unmarked and use a filename that makes the reviewed version easy to distinguish.

What highlighting is useful for

Contract review

Emphasize a deadline, amount, renewal clause, or question for discussion without altering the source wording.

Study and research

Mark definitions, evidence, or passages to revisit while keeping the complete page in context.

Invoice and form review

Draw attention to a total, due date, missing field, or instruction that another person must check.

Client feedback

Point the recipient to a specific part of the page and repeat the same instruction in the message when clarity matters.

Highlight, marker, stamp, and redaction are not interchangeable

Highlight

A translucent emphasis mark that should leave the text readable.

Marker

A freehand drawing tool for circles, underlines, arrows, or handwritten visual notes.

Stamp

A visual status or workflow mark placed on the page. It is not automatic proof of approval.

Redaction

A sensitive-data workflow that must remove or sanitize underlying content, not merely cover it with color.

Make the highlighted PDF readable for more people

Do not rely on color alone

Mention the highlighted clause or page in the accompanying message so the instruction remains clear to people with color-vision differences.

Keep sufficient contrast

Choose a highlight that is visible against the page but still allows dark and colored text to be read.

Use consistent meaning

If several colors appear, keep their purpose consistent and explain the legend rather than making the recipient guess.

Check the final attachment

Open the exported file from the destination and verify the highlight did not shift, disappear, or cover text.

Frequently asked questions

Can I highlight a PDF on iPhone?

Yes. Import the PDF into ScanLens, choose Highlight in Markup, mark the passage, and export a separate annotated copy.

Can I choose a highlight color?

The Markup interface exposes color controls. Choose a color that keeps the underlying text readable and verify the export.

Does highlighting change the original PDF text?

No. A highlight is a visual annotation over the page. Keep the clean source and export a separate highlighted copy.

Can I use a highlight to hide confidential text?

No. Highlighting is for emphasis and can leave the underlying visual and text content available. Use a validated redaction workflow.

Why did my highlight cover the words?

Use the dedicated translucent Highlight tool, adjust the size or color, zoom in, and remove or redo any mark that makes the text harder to read.

Make the important part easy to see—and still easy to read

Mark the passage, check contrast and placement, and send a separate reviewed copy from iPhone.

Download on the App Store