Leet Speak Translator
Type text and see it as leet speak (1337 5p34k) as you type, using either the six classic substitutions or an advanced set that adds more letters and the word elite. Choose whether untranslated letters keep their case, or paste leet and get a best-effort plain-text version. Free, no sign-up, and nothing is uploaded.
Direction
Level
A Short History of 1337
Leet speak emerged on 1980s bulletin-board systems, where "elite" users — those with access to the best file areas — signalled status by writing with number and symbol substitutions. "Elite" became "leet", and "leet" written in its own alphabet became 1337. The style spread through hacker culture, IRC, and later online gaming, where 1337 still survives as shorthand for skill. Today it is mostly used for fun, for nostalgic gamer tags, and occasionally to dodge naive text filters.
How to Use the Leet Speak Translator
- 1. Choose a direction. Text → Leet swaps letters for numbers and symbols; Leet → Text reverses the substitutions.
- 2. Pick a level (Text → Leet only). Basic uses six substitutions; Advanced adds three more and a whole-word rule.
- 3. Decide about case. With Preserve case of untranslated letters on, letters that have no leet form keep their capitals. Off, they are all lowercased.
- 4. Copy the result. The output updates as you type; Copy Result copies it.
The Substitution Tables
| Letter | Basic | Advanced |
|---|---|---|
| a | 4 | 4 |
| e | 3 | 3 |
| i | 1 | 1 |
| o | 0 | 0 |
| s | 5 | 5 |
| t | 7 | 7 |
| b | b | 8 |
| g | g | 9 |
| l | l | |_ |
The advanced level also rewrites the whole word elite (in any capitalisation) as 1337 before the letters are substituted. Substitution works on the letter, not its case, so A and a both become 4. Everything else — other letters, digits, spaces and punctuation — is left as it is.
Worked Example
Plain text
Cite Your Sources, Please!
Basic
C173 Y0ur 50urc35, Pl3453!
Advanced
C173 Y0ur 50urc35, P|_3453!
Plain text
Elite hacker skills
Basic
3l173 h4ck3r 5k1ll5
Advanced
1337 h4ck3r 5k1|_|_5
Notice that the capital letters C, Y and P survive in the first example because Preserve case is on, and that basic leaves l alone while advanced turns it into the two characters |_, so the advanced version is longer. In the second example advanced turns the whole word elite into 1337 rather than 3l173.
Going Back: Leet to Text
The reverse mode scans left to right and replaces 1337 with elite and each substitution with its letter. It cannot know which digits were letters in the first place, so every 4, 3, 1, 0, 5, 7, 8 and 9 becomes a letter, whether or not it started as one: Call 555-0100 in 2024 comes back as Call sss-oioo in 2o2a. Likewise, 1 always becomes i, never l, so |_ is the only way to get an l. Replaced letters come back in lowercase. It reads well when the input really is leet and badly when it contains ordinary numbers. Check the result.
Leet Is Not Security
Leet speak began as a playful alphabet in 1980s bulletin-board culture and lives on in gamer tags and jokes. Its substitutions are the first thing password-cracking programs try, so p4ssw0rd is no harder to guess than password. Current guidance such as NIST SP 800-63B favours length over character tricks; use the Password Generator for something random, and the Password Strength Checker to see how a password you already use holds up.
Which Tool Do You Need?
For other text games, the Pig Latin Translator rewrites words by sound-based rules, the Morse Code Translator produces dots and dashes, and the Caesar Cipher shifts letters through the alphabet. For changing capitals without any substitutions, use the Case Converter.
Frequently Asked Questions
- What is leet speak?
- An informal alphabet that replaces letters with look-alike numbers and symbols: a becomes 4, e becomes 3, t becomes 7. It grew from 1980s bulletin-board and early hacker culture, where it signalled that you were one of the "elite".
- What is the difference between the basic and advanced levels?
- Basic substitutes six letters: a to 4, e to 3, i to 1, o to 0, s to 5 and t to 7. Advanced adds b to 8, g to 9 and l to |_, and rewrites the word elite as 1337.
- Can I translate leet speak back to normal text?
- Yes, in best-effort fashion. The tool maps the substitutions back, but a 1 might have been an i, an l or a genuine 1, and real numbers in the text are turned into letters, so check the result.
- What does Preserve case do?
- With it on, letters that have no leet substitute keep their original capitals. With it off they are lowercased. Substituted letters become numbers and symbols, which have no case.
- Why is it called 1337?
- It is the word leet written in leet: 1 for l, 3 for e, 7 for t. Leet is short for elite.
- Does leet speak make a password stronger?
- No. Cracking tools try these substitutions early, so p4ssw0rd is barely stronger than password. Make it longer or random instead.
- Is my text uploaded anywhere?
- No. The conversion runs in your browser and nothing you type is sent anywhere.