Every language has a characteristic letter frequency distribution — in English, 'e' is by far the most common letter, while 'z' and 'q' are rare. This tool counts how often each letter appears in your text and displays the results as a simple frequency chart.
Letter frequency analysis is a foundational technique in classical cryptography, since substitution ciphers preserve the frequency pattern of the original letters even though the symbols change, making it possible to guess likely substitutions.
Beyond cryptography, it's also used in linguistics, typography (to help decide which keys deserve prime keyboard real estate), and just as an interesting way to fingerprint a piece of writing.
Because everything runs locally in your browser, results appear instantly and nothing you type or upload is ever sent to a server.
Bookmark this page if you expect to use this tool regularly — it loads fast and behaves the same way every time, with no account needed.
This kind of task shows up constantly in everyday writing, coding, design, and admin work, which is exactly why a dedicated, focused tool saves so much back-and-forth.
A tool that does one job well, without a cluttered interface or unrelated features competing for attention, tends to be faster to use than a heavier all-in-one app.
If you find yourself needing this conversion or calculation often, keeping this page open in a tab is usually faster than digging through a bigger software suite's menus.
Because there's no sign-up or installation step, you can jump straight from search result to working tool in a couple of seconds.
Because there's no sign-up or installation step, you can jump straight from a search result to a working tool in a couple of seconds.
If you find yourself needing this often, keeping this page open in a tab is usually faster than digging through a bigger software suite's menus.
Frequently asked questions
Why is this useful for solving substitution ciphers?
Because a simple substitution cipher swaps letters one-for-one, the frequency pattern of the encrypted text still matches the frequency pattern of the original language, revealing likely letter mappings.
Does this count uppercase and lowercase separately?
No, letters are counted case-insensitively so 'E' and 'e' contribute to the same tally.