Text highlighting not working in PDFs on macOS Tahoe 26: how to fix

After updating to macOS Tahoe 26, many Mac users faced the same issue: text selection in PDFs via the Preview app stopped working properly. Instead of the usual yellow highlighter, blue rectangles appear around the text, sometimes the selection doesn't work at all, or it works on one page and not on another.

This is not an issue with a specific file. The system bug affects many users — especially when working with documents containing tables, such as bank statements, invoices, and contracts.

Why this happens

The exact cause has not yet been identified by Apple, but the most likely ones include:

— Corrupted or outdated Preview app cache files

— Incompatibility of the new PDF renderer with certain file formats

— System glitches after the macOS update

Method 1. Re-save PDF via Print

This is the easiest method and helps in most cases.

1. Open the PDF in Preview.

2. Press Cmd + P.

3. In the lower-left corner, click "PDF" → "Save as PDF".

4. Save the file under a new name.

5. Open the new file and check the selection.

After this, the PDF is regenerated, and the selection usually starts working normally.

Method 2. Export as PDF/A

PDF/A is a standardized archival format. Some users note that the issue goes away after exporting.

1. Open the PDF in Preview.

2. Go to: File → Export.

3. In the format list, select PDF/A.

4. Save the file and reopen it.

This method doesn't always work, but it is worth trying if the first one didn't help.

Method 3. Clear cache and boot in Safe Mode

Corrupted cache files can interfere with correct text selection.

Step 1. Clear the Preview cache:

1. Open Finder → Go → Go to Folder.

2. Enter ~/Library/Caches/com.apple.Preview and press Enter.

3. Delete the contents of the folder.

4. Restart Preview and check the PDF.

Step 2. If that didn't help, boot your Mac in Safe Mode:

1. Shut down your Mac.

2. Intel: turn it on and immediately press and hold Shift. Apple Silicon: press and hold the power button, select the disk, press and hold Shift → "Continue in Safe Mode".

3. Check the selection in Safe Mode.

4. Restart your Mac normally.

Safe Mode clears the system cache and disables third-party extensions — this helps determine whether the issue is related to macOS or installed software.

If nothing helped

Sometimes the cause is deeper: a conflict of system components or an update error. If none of the methods worked, bring your device to Iclub Service for diagnostics. We will figure out the cause and restore normal operation of your Mac. You can book an appointment online or by phone.