Left Function in Excel is a type of text function in Excel which is used to give the number of characters from the start from the string which is from left to right. In other words, you can use this function to get the index of a particular word in a text string. The left function in Excel is a simple Excel formula that returns the leftmost 2 characters of a text string. Enter text into cell A1, press the Auto filter button, and then type LEFT (A1,2). To return the entire text string, enter "=" and press twice. Type LEFT(refers to cell) in the Or select a category drop-down box, select Text. Under Select a function, select LEFT. All cells on one side of this cell will be cut off and removed altogether, leaving just the number of columns looked at by this function.