Something wrong with this tool?
About Rot13 Decoder Online
This tool reverses ROT13 encoding back to plain text. Because ROT13 is symmetric (the shift wraps around a 26-letter alphabet exactly twice), applying ROT13 to ROT13 output recovers the original. So this tool actually runs the same algorithm as the ROT13 encoder.
Use it to read text you suspect is ROT13-encoded, to decode an old Usenet post you've found, or to peek at a spoiler that's been ROT13'd in a forum or fan-fiction warning.
The tool preserves punctuation, numbers, and whitespace — only A-Z letters are shifted. Case is preserved, so uppercase stays uppercase after decoding.
How to use this tool
How to undo ROT13 substitution on text
Paste the ROT13 text
Drop the encoded string into the "Text" field. The tool applies a 13-position shift back to each A–Z letter (`N↔A`, `O↔B`, …, `Z↔M`). Case is preserved; non-letters pass through unchanged.
Press Run
Result returns a single `decoded` field. Examples: `Uryyb, Jbeyq!` → `Hello, World!`; `5 CZ` → `5 PM`. Because ROT13 is an involution, this decoder is mathematically identical to the encoder — the labels just signal intent.
Telling encoded from plain text
ROT13 of normal English looks like word-shaped gibberish: vowels move, but spaces and punctuation stay. If the input looks like prose with `J`, `K`, `Q`, `X` showing up more than usual, it's probably ROT13.
Don't decode what isn't ROT13
If your input is real prose, running it through this tool just produces gibberish. Use only when you're confident the source was ROT13 (spoiler block, puzzle answer, USENET-era post).