Converter Tools
ROT13 Encoder Decoder
Encode and decode ROT13, ROT5, ROT18, and ROT47 in your browser. Same button encodes and decodes because every variant is its own inverse.
Variant
Pick a rotation. The same button encodes and decodes because each rotation is exactly half the alphabet width.
Rotates each Latin letter by 13 positions. Digits, punctuation, and spaces pass through unchanged.
0 characters will be rotated. 0 pass through unchanged.
Output
Result will appear here as you type.
Click Use as input to feed the result back into the box, which recovers the original because ROT13 is its own inverse.
Mapping
Top row is the input character. Bottom row is what it becomes under ROT13.
ROT13, ROT5, ROT18, and ROT47 are obfuscation tricks, not security. They hide spoilers, light text from casual reading, and answer puzzle prompts. Do not use them to protect anything that matters. Pair real secrets with a password manager or proper encryption.
How to use
- Pick a variant: ROT13 for letters, ROT5 for digits, ROT18 for both, or ROT47 for printable ASCII.
- Type or paste text into the Input box. The Output panel updates as you type.
- Click Copy result to copy the rotated text, or Use as input to round-trip the result back to the original.
- Try the Load sample buttons to see plain text, a ROT13 cipher, a ROT47 example, or a hidden spoiler in action.
About this tool
ROT13 Encoder Decoder rotates each character by a fixed number of positions inside a fixed alphabet, then leaves everything else untouched. Because the rotation is exactly half the alphabet width, applying the same operation twice returns the original input, so encoding and decoding use the same button. The tool supports four well-known variants: ROT13 rotates the 26 Latin letters by 13 and is the classic Usenet spoiler hider; ROT5 rotates the 10 digits by 5 and is used to scramble numeric IDs without touching surrounding text; ROT18 combines ROT13 and ROT5 so letters and digits both shift in one pass; ROT47 rotates the 94 printable ASCII characters from '!' to '~' by 47, which covers digits, letters, and common punctuation in a single operation. A live mapping view shows exactly which character each input maps to, an affected-versus-passthrough counter explains what the rotation will touch in your current text, and a Use as input button feeds the result back in so you can verify the round trip. Everything runs in the browser. Nothing you paste is uploaded.
Free to use. Works in your browser. No signup, no login.
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