Text

Leet Speak Converter

Convert normal text to leet speak (1337) by substituting letters with numbers and symbols for that classic internet style.

Loading interactive tool…

Embed this tool on your site

About this tool

The Leet Speak Converter transforms ordinary text into leet speak (also spelled l33t or 1337) — the internet subculture substitution cipher where letters are replaced with visually similar numbers or symbols. It offers three intensity levels. Basic swaps six letters: A→4, E→3, I→1, O→0, S→5 and T→7. Advanced uses A→4, E→3, I→|, O→0, S→$, T→+ and adds B→8, G→9 and L→1. Extreme draws letters from symbols, such as A→/-\, O→(), L→|_, N→|\|, M→|\/| and W→\/\/, which is much harder to read. Upper and lower case letters get the same substitution, other characters are kept, and every substitution is plain ASCII. Leet speak originated in the 1980s hacker and bulletin board culture and remains popular for usernames, gaming handles, memes, and stylized text.

Why use it

  • Three intensity levels from subtle to extreme substitution.

  • Includes both classic number substitutions and symbol variants.

  • Output updates as you type or change the level once you have converted.

  • Entirely browser-based with no setup required.

  • Three preset levels remove guesswork about how aggressive to make the substitution.

  • All substitutions are plain ASCII, so the output can be typed on any keyboard.

How to use

  1. Type or paste your text into the Input text box.
  2. Select an Intensity: Basic, Advanced, or Extreme.
  3. Click Convert to fill the Output box; after that it updates as you type or switch intensity.
  4. Try each intensity to find the look you want.
  5. Click Copy to copy the leet output for usernames, slogans, or stylized headlines.

When it helps

  • Creating stylized usernames or gaming handles.
  • Generating leet versions of slogans or memes.
  • Demonstrating letter-number visual similarity for educational purposes.
  • Having fun transforming names and words in the classic hacker style.
  • Designing nostalgia-themed graphics or t-shirt slogans.
  • Generating retro-style passwords (though never use leet alone for security).

Examples

Basic level

Input

Hello World

Expected result

H3ll0 W0rld

Advanced level

Input

Hacker Username

Expected result

H4ck3r U$3rn4m3

Extreme level

Input

Elite Coder

Expected result

3|_|+3 C()d3r

Tips

  • For gaming usernames, Basic or Advanced usually balances readability and 'leet' aesthetic best.
  • Avoid Extreme level for anything that needs to be typed back from memory — multi-symbol letters like |\/| are hard to recreate.
  • Combine leet with the Fancy Unicode Fonts tool for a maximum-style internet retro look.
  • Test leet usernames in your target platform's signup form before committing — some sites reject special characters.
  • For accessibility, avoid leet in primary headings or navigation — screen readers may read characters one-by-one.

Frequently Asked Questions

What is leet speak?
Leet speak is a substitution cipher where letters are replaced by numbers or symbols that resemble them visually (e.g. E→3, A→4). It originated in early internet and hacker culture.
What is the difference between Basic, Advanced, and Extreme levels?
Basic replaces a, e, i, o, s and t with 4, 3, 1, 0, 5 and 7. Advanced uses 4, 3, |, 0, $ and + for those letters and also turns b, g and l into 8, 9 and 1. Extreme builds letters from symbols (a → /-\, o → (), b → |3, l → |_, n → |\|, m → |\/|, w → \/\/).
Is leet speak the same as 1337?
Yes. '1337' is itself a leet speak spelling of 'leet' (elite), so the terms are interchangeable.
Can I convert back from leet speak to normal text?
This tool converts text to leet. Converting back is ambiguous since many normal letters map to the same leet character, so an exact reversal is not possible.
Will it convert numbers in my text?
Numbers in the source text are left as-is since they are already numeric characters.
Is leet speak good for password security?
No. Leet substitutions are well-known and cracking tools test them automatically. Use a passphrase or password manager instead of leet variants.
Will leet speak letters render on all platforms?
Yes. Every substitution at every level is a plain ASCII digit or symbol, so the output renders everywhere. Some sites reject characters like |, / or \ in usernames, though.
Can I customize the substitutions?
The tool uses preset Basic/Advanced/Extreme mappings. Custom mapping is not available, but you can apply a follow-up find-and-replace for one-off tweaks.

Explore the category

Bionic Reading Converter Convert text to bionic reading format by bolding the first few letters of each word to guide the eye and boost reading speed. SpongeBob Text Generator Convert text to the alternating capital/lowercase 'Mocking SpongeBob' meme format — perfect for sarcastic internet replies. Case Converter Convert text between letter cases Text Cleaner Remove extra spaces, symbols and more Morse Code Translator Convert text to Morse code and decode Morse to text Line Numberer Add line numbers to text with custom start, padding, separator, and empty-line handling.

Glossary

Leet (1337)
An alternative alphabet where letters are replaced with numbers or symbols that visually resemble them.
Substitution cipher
A method of disguising text by replacing letters with other characters; leet is a simple, well-known example.
Eleet/Elite
The original meaning of '1337' — referring to skilled hackers or gamers in early internet culture.
Hacker culture
The broader subculture of programming, security research, and tinkering where leet speak originated.
BBS (Bulletin Board System)
Pre-web text-based community platforms where leet speak first emerged in the 1980s.
Glyph similarity
How visually similar two characters are — leet substitutions rely on glyph similarity (E≈3, A≈4).
A LITTLE HELP. A LOT DONE.
Good tools.
Great flow.

Your shortcut to the everyday. Create, convert, calculate,
and get back to what you love.

✓ Free to use✓ No sign-up✓ 500+ possibilities