Caesar Cipher Encoder / Decoder
Shift Latin letters for puzzles and classroom exercises.
Tool inputs stay in your browser · optional AI search sends your query
Good to know: Shifts A–Z/a–z while preserving other characters. A negative shift decodes a positive shift. Educational only: this cipher is easily broken and must not protect passwords or private data.
How to use it (step by step)
- 1Type or paste your text into the “Input” box. There is already an example in it so you can see how it works; press Clear to start with your own.
- 2Choose your settings: “Letter shift (negative to decode)”.
- 3The answer appears right away in the “Result” box. No button needed.
- 4Press Copy and paste the result wherever you need it.
Words to know
- Morse code / cipher
- Old ways of writing messages with codes: Morse uses dots and dashes; a cipher swaps letters by a rule. Fun for puzzles, not for real secrets.
- Public vs private IP
- Your router gives each device a private IP (like 192.168.1.5) at home. The internet only sees one public IP for your whole house.
More in Text & Writing
Speech Presentation Duration CalculatorEstimate spoken presentation duration based on word count and speaking pace.Word & Character CounterCount words, characters, sentences, paragraphs and reading time.Case ConverterUPPERCASE, lowercase, Title Case, Sentence case, camelCase, snake_case and more.Remove Extra SpacesCollapse double spaces, trim lines and remove empty lines.Remove Line BreaksJoin lines into one paragraph, e.g. text copied from a PDF.Remove Duplicate LinesKeep only unique lines from a list, in the original order.