Convert text to 1337speak with a basic or aggressive substitution table, or flip the direction to translate leetspeak back into readable text.
🔒 Your text stays on your device and is never uploaded.
Type or paste text and choose a substitution level. Basic mode only swaps the five most recognizable letters (e, a, i, o, s) with lookalike numbers, giving a subtle leetspeak feel while staying readable. Aggressive mode substitutes every letter of the alphabet using a fuller symbol table for a much heavier 1337 look. Flip the direction toggle to attempt the reverse: decoding leetspeak symbols back into ordinary letters using the same table.
Choose a light, readable basic conversion or a full aggressive substitution table for maximum leetness.
Toggle the direction to translate leetspeak back to text using a best-effort greedy decode.
Conversion runs locally in your browser. Nothing you type is uploaded or stored anywhere.
Leetspeak is an informal alphabet that replaces letters with visually similar numbers or symbols, such as writing "leet" as "1337" or "elite" as "31337".
Basic only swaps the most recognizable letters: e to 3, a to 4, i to 1, o to 0 and s to 5. Aggressive substitutes every letter with a symbol or multi-character combination for a much heavier leetspeak look.
Yes. Switch the direction toggle to From leetspeak. It is a best-effort decode because some substitutions are ambiguous or reused for more than one letter, especially at the aggressive level.
Every letter has a substitution at the aggressive level, but the basic level only maps e, a, i, o and s, so every other letter is intentionally left unchanged.
No. Conversion happens locally in your browser using JavaScript, so nothing you type is sent to a server.