Text box lagging when typing inside

If the text box lag still persists even after disabling hardware acceleration, testing at 100% zoom, and simplifying the workbook, then we’re probably dealing with a rendering or memory leak issue that Excel sometimes develops with text boxes in newer builds (especially Office 365 and Excel 2021+).

First, I'd like to point out that it's always good to share information about the problem with the digital environment. Digital environments such as Excel version, Windows (OS) version, storage location (OneDrive, SharePoint, hard disk, etc.), how big the workbook is, allow you to arrive at a solution proposal more quickly and accurately.

Whatever the case, here’s some more set of steps you can try…

Run Excel in Safe Mode

This launches Excel without any add-ins, startup templates, or custom graphics hooks.

Close Excel completely.

Press Windows + R, type:

excel /safe

and press Enter.

Open your workbook and test typing in a text box.

If the lag disappears, one of your add-ins (even a Microsoft one like Power Query or PowerPivot) is interfering. You can then re-enable add-ins one by one under File → Options → Add-ins → COM Add-ins → Go….

Disable “Modern Comments” and other experimental UI features

Recent Office builds use web-rendered layers for comments, shapes, and text boxes — which can lag badly on some systems.

Try:

• Go to File → Options → General.
• Under Comments, choose “Use classic comments” (if available).
• Restart Excel and test.

Clear Excel’s Rendering Cache

Corrupt graphics cache files can cause lag in shape/textbox editing.

• Close Excel.
• Press Windows + R → type:
• %appdata%\Microsoft\Excel
• Delete any files named Excel*.xlb (these store toolbar/cache settings).
• Restart Excel — it’ll recreate them automatically.

There are still a few suggested solutions, but you would have to go into the “regedit” and make changes that might not be helpful if you don't know in advance what digital environment you are dealing with.