Removing Duplicates With UNIQUE

The UNIQUE function returns a list with duplicates removed, keeping only the distinct values from a range. It spills the result, so a single formula produces a clean, always-current list.

This is far easier than the old Remove Duplicates menu command, which made a static copy you had to redo whenever the data changed.

UNIQUE takes one required argument and two optional ones:

=UNIQUE(array, [by_col], [exactly_once])

• array is the range to deduplicate.
• by_col set to TRUE compares columns instead of rows (rarely needed).
• exactly_once set to TRUE returns only values that appear a single time.

Most of the time you just supply the array.