Excel Short & Sweet Tip #7(Highlighting External Links) by David Hager

Using conditional formatting to highlight external links has been used before

https://www.extendoffice.com/documents/excel/1539-excel-highlight-external-links.html

but it required a VBA solution. Now, with Excel’s new FORMULATEXT function, it can be accomplished using only Excel formulas. So, using the following formula defined as IsExternalLink

=FIND(“[“,FORMULATEXT(D10))

Conditional formatting will highlight the cells containing “[“, which is associated with external link formulas. But, a more robust formula can also be used, as shown below.

=FIND(“[“,FORMULATEXT(D10))+FIND(“]”,FORMULATEXT(D10))