Counting one letter is easy enough to do by eye in a sentence and impossible by eye in a page, which is the whole reason this tool exists. Type the letter, read the number, and see every occurrence marked in the text so you can go straight to them.
Most letter counters stop at one letter at a time, A to Z only. This one counts several targets at once so you can compare them, and a target can be a word, a pair of letters, a punctuation mark, a digit or an emoji rather than only a letter. The full frequency table underneath ranks every character in your text against the usual distribution of English, which is the view you want for a crossword, a word game or a substitution cipher.
