Leet Speak Converter
Convert text into 1337 speak.
Overview
Convert ordinary text into 1337 speak (leet speak) — the old internet substitution style where letters are replaced with visually similar numbers and symbols. "Elite" becomes "31337", "hacker" becomes "h4ck3r", and so on. The tool can also reverse the process, decoding leet back into plain English.
Game tag generators, gamertag namers, retro forum nostalgists, and security trainers demonstrating password-policy weaknesses all use it. It's also handy for sanitizing tests of profanity filters and for username brainstorming where the obvious spelling is already taken.
How it works
Leet speak originated in 1980s BBS culture. A standard substitution table maps letters to similar-looking digits and symbols: A↔4, B↔8, E↔3, G↔6 or 9, I↔1, L↔1, O↔0, S↔5, T↔7, Z↔2. Variants add more aggressive substitutions like H↔|-|, M↔//, or W↔//. The tool offers a basic mode (just the common ones) and an extreme mode (the full lookalike set).
Examples
Input: Hello World
Output: H3110 W0r1d (basic)
Output: |-|3110 \/\/0|2|_|) (extreme)
Input: elite hacker
Output: 31173 h4ck3r
Input (decode): l33t 5p34k
Output: leet speak
FAQ
Is leet speak actually used in security?
Mainly as a teaching example. Password policies that require numbers and symbols are easily defeated by leet substitutions ("P4ssw0rd!"), which is why modern guidance emphasises length and uniqueness over character variety.
Why are there so many variants?
Leet evolved on dozens of BBS and IRC scenes independently, with each community adding its own substitutions. There's no single canonical mapping.
Can decoding be ambiguous?
Yes. "0" could be O or zero, "1" could be I or L or one. Decoding uses heuristics and dictionary checks; expect occasional misses for novel inputs.