ROT13 Encoder
Apply the classic ROT13 letter rotation.
- Reading time:
- 2 min
- Last updated:
- Price:
- Free, no signup
Type or paste text to see the result.
What the ROT13 Encoder does
ROT13 moves every letter 13 places along the alphabet: A becomes N, B becomes O, and 'Spoiler' becomes 'Fcbvyre'. Numbers, spaces and punctuation stay exactly where they are.
Because the alphabet has 26 letters, running ROT13 twice brings you back to the original — the same box both hides and reveals text.
Why the ROT13 Encoder is useful
ROT13 has been used on Usenet and forums for decades to hide spoilers, puzzle answers and punchlines so readers only see them if they choose to.
It isn't security — anyone can reverse it instantly — but that is the point: it's a polite curtain, not a lock.
Also known as: rot13, letter rotation, free rot13 encoder, online rot13 encoder, rot13 encoder online free, rot13 encoder tool, best rot13 encoder tool.
How to use the ROT13 Encoder
- 1
Type your text
A spoiler, answer or joke punchline.
- 2
Copy the scrambled version
Share it where others can choose to decode it.
- 3
Decode the same way
Paste ROT13 text in and the original comes out.
Key features
- One box for encoding and decoding
- Keeps upper and lower case
- Leaves digits and symbols unchanged
- Instant live result
Benefits
- Share spoilers without ruining things for others
- Hide quiz answers in plain sight
- Teach the basic idea of substitution ciphers
Real-life use cases
Book club discussion
A member posts the twist ending in ROT13 so people who haven't finished the book can scroll past safely.
Puzzle hunt clue
A teacher writes the final answer of a classroom puzzle in ROT13 at the bottom of the worksheet for students to check themselves.
Tips for the best results
- Only A–Z letters change; Urdu, accented and non-Latin letters pass through untouched.
- Never use ROT13 for passwords or private data — it offers zero protection.
- For a different shift amount, try the Caesar Cipher tool.
Conclusion
Use ROT13 to tuck away spoilers and answers so readers decide when to see them — and decode them with the same box.
Frequently asked questions
How do I decode ROT13?
- Paste the scrambled text in. Applying ROT13 again restores the original.
Is ROT13 encryption?
- Not in any useful sense. It has no key and is reversed instantly.
Does it change numbers?
- No. Only English letters are shifted. ROT5 is a separate scheme for digits.
Why 13?
- It's half of 26, which is what makes encoding and decoding the same operation.
What is ROT13 of 'Hello'?
- 'Uryyb'.
Where is ROT13 still used?
- Forums, puzzle sites, geocaching hints and programming exercises.
Related tools you may need
- Caesar Cipher — Encrypt or decrypt text with the classic Caesar shift (13).
- URL Encoder — Percent-encode text for safe use in URLs.
- Base64 Encoder — Encode text to Base64 (UTF-8 safe).
- Morse Code Encoder — Convert text into international Morse code.
- HTML Encoder — Escape HTML special characters (< > & " ').
- HTML Entity Encoder/Decoder — Convert text to HTML entities and back again.
- Morse Code Decoder — Decode Morse code back into readable text.
- HTML Decoder — Decode HTML entities back to plain characters.
Keep exploring
Browse the full tools directory, filter by category, or read guides on the Text Tools Hub blog.