How to undo ROT13 substitution on text

1. 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.

2. 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.

3. 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.

4. 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).