ROT13 / ROT47 Encoder

Overview

Applies ROT13 and ROT47 side by side to the same input, so you can compare both rotation ciphers at once. ROT13 scrambles the 26 letters; ROT47 scrambles all 94 printable ASCII characters including digits and punctuation. Both are self-inverse, and both outputs are click-to-copy.

How It Works

Type or paste text into the input area. Two output panels appear side by side, each updating live: the left applies ROT13, the right ROT47. Because each panel holds a different cipher of the same text, you can immediately see which characters each scheme touches — ROT13 leaves digits and symbols alone, ROT47 visibly moves them. Switching between decoding and encoding requires nothing: applying the same operation again restores the original.

Step-by-Step Usage Guide

1. Paste the text into the input area.
2. Read the ROT13 panel for the letters-only rotation, the ROT47 panel for the full printable-ASCII rotation.
3. Copy whichever result you need with a click on its panel.
4. To decode, paste the encoded text and read the same panels — both ciphers undo themselves.

Technical Specifications & Standards

Both transforms are rotation ciphers over a fixed alphabet, differing only in scope. ROT13 shifts letters by 13 — half of 26 — so encoding and decoding are the identical operation, the property that made it the net's standard for spoilers and puzzle answers; digits, punctuation and non-English letters pass through untouched. ROT47 operates on the 94 printable ASCII characters from code 33 (!) to 126 (~), shifting by 47 — half of 94 — so it is likewise its own inverse, but it rotates numbers and symbols too: a year like 2024 comes out as a_ac. The arithmetic for both is a rebased modulo — for ROT47, 33 plus the remainder of (code minus 33 plus 47) over 94 — with characters outside the alphabet left as-is. Practical notes: because ROT47 mixes punctuation into the rotation, text containing URLs, code or email addresses comes out unrecognisable rather than merely letter-scrambled; and neither cipher carries any security — both are broken by inspection and exist for obfuscation, puzzles and convention.

Targeted Use Cases

• Hiding a spoiler, answer or punchline in a forum post using the ROT13 convention others recognise.
• Decoding a ROT13 or ROT47 string found in a puzzle, CTF challenge or retro software.
• Comparing the two ciphers to see why ROT47 suits strings containing digits and symbols.
• Obfuscating configuration values or quiz answers from a casual glance, without any security pretence.

Notes & Gotchas

• Use ROT13 for prose where numbers should stay readable; use ROT47 when everything should be scrambled.
• Never use either cipher for security — both fall to instant inspection, and ROT13 of anything is one click away for any reader.
• Remember both are self-inverse: there is no separate decode step, just apply the same panel again.
• Characters outside the covered alphabets (accents, emoji, CJK) pass through unchanged in both panels.

Frequently Asked Questions