If you want to highlight the differences between two columns of data with conditional formatting you can do so with a simple formula that uses the" not equal to" operator (e.g. ) and mixed references.
For example, if...

To allow a user to enter only uppercase TEXT, you can use data validation with a custom formula based on the UPPER, EXACT, and AND functions.
In the example shown, the data validation applied to C5:C7 is:
=AND(EXACT...

To verify that multiple cells have the same value with a case-sensitive formula, you can use a simple array formula based on the EXACT and AND functions. In the example shown, the formula in G5 is:
=AND(EXACT(B5:F5,B5...

Note: Excel contains many built-in "presets" for highlighting values with conditional formatting, including a preset to highlight cells that contain a specific value. However, if you want more flexibility, you can use...

If you need to compare two text strings in Excel to determine if they're equal, you can use the EXACT function. For example, if you want to compare A2 with B2, use:
=EXACT(A2,B2)
If the two strings are identical,...

Case sensitive lookups in Excel
By default, standard lookups in Excel are not case-sensitive. Both VLOOKUP and INDEX/MATCH will simply return the first match, ignoring case.
A direct way to workaround this limitation...

To allow only values that begin with certain text, you can use data validation with a custom formula based on the EXACT and LEFT functions.
In the example shown, the data validation applied to C5:C9 is:
=EXACT(LEFT(...

To confirm two ranges of the same size contain the same values, you can use a simple array formula based on the AND function. In the example shown, the formula in C9 is:
{=AND(B5:D12=F5:H12)}
Note: this is an array...

Note: Excel contains many built-in rules for highlighting values with conditional formatting, including a rule to highlight cells that end with specific text. However, if you want more flexibility, you can use your own...

To count cells that contain certain text in a case-sensitive manner, you can use a formula that uses the EXACT function along with SUMPRODUCT.
In the example, there is a list of names in a named range ("names"), B3:B9...

Case-sensitive lookup
By default, standard lookups with VLOOKUP or INDEX + MATCH aren't case-sensitive. Both VLOOKUP and MATCH will simply return the first match, ignoring case.
However, if you need to do a case-...

To perform a case sensitive match, you can use the EXACT function together with MATCH in an array formula. In the example show, the formula in E8 is:
{=MATCH(TRUE,EXACT(B5:B11,E6),0)}
Note: this is an array formula...