1337 / Leet Speak

Convert text to leet (a=4, e=3, i=1, o=0, s=5, ...).

Tool Text Codecs Updated Apr 20, 2026
How to Use
  1. Type or paste your input on the left.
  2. The result appears live on the right - no buttons needed.
  3. Copy the output with one click.

About this codec

Convert text to leet (a=4, e=3, i=1, o=0, s=5, ...).

About Leetspeak

Leetspeak is an internet style that replaces letters with similar-looking numbers and symbols (E→3, A→4). This tool lets you transform text with Leetspeak instantly and entirely in your browser. It is commonly used for gaming culture and casual obfuscation.

💡Worked example: ELITE31173
⚠️Leetspeak is a classical cipher, not real security — it is trivially broken and is meant for puzzles, learning, and fun. For confidentiality use modern encryption, not a classic cipher.

How to use it

Type or paste your text into the box and it turns into Leetspeak live as you type — everything runs locally in your browser. Learn more in the Knowledge Base.

Frequently Asked Questions

Does this leave my browser?

No - the conversion runs entirely in JavaScript on this page.

What does Leetspeak look like?

ELITE becomes 31173. Leetspeak is typically used for gaming culture and casual obfuscation.

Does my text leave my browser?

No. The Leetspeak conversion runs entirely in JavaScript on this page — nothing is uploaded, and it works offline.

Is Leetspeak secure?

No — Leetspeak is a classical cipher that is easy to break. Use it for puzzles and learning, and use real encryption when you actually need confidentiality.

Common Use Cases

Gaming culture and casual obfuscation

Leetspeak is commonly used for gaming culture and casual obfuscation — produce it here in one step.

Learning & puzzles

See how text maps to Leetspeak — handy for coursework, CTF challenges, and puzzle hunts.

Private by design

Everything runs locally in your browser, so you can paste sensitive text without it leaving your device.

Last updated: