Text Cipher
Encode or decode text with a Caesar cipher or Base64 online for free. Clearly not real encryption — for puzzles and obfuscation, not securing sensitive data.
Neither of these is real encryption. A Caesar shift has only 25 possible keys and Base64 has no key at all — both are instantly reversible by anyone. Use them for puzzles or obfuscation, not for protecting anything sensitive.
Your files are processed locally in your browser and are not uploaded to our servers.
How to use Text Cipher
- 1
Paste your text into the box.
- 2
Choose Caesar Cipher (pick a shift amount) or Base64.
- 3
Click Encode or Decode.
- 4
Copy or download the result.
Common uses
- Solving or creating a Caesar-cipher puzzle
- Encoding/decoding Base64 strings from an API response, a data URL, or a config value
- Teaching or learning how classical substitution ciphers work
Supported formats and limitations
Accepts text, up to one file at a time.
- Neither method is real encryption — a Caesar shift has only 25 possible keys and Base64 has no key at all, so both are instantly reversible by anyone. This is disclosed clearly on the tool page, not left implied.
- The Caesar cipher only shifts the 26 ASCII letters — numbers, punctuation, and non-Latin letters (including Vietnamese diacritics) pass through unchanged, since a Latin-alphabet shift cipher has no defined behavior for them.
Frequently asked questions
No, and this page says so directly. A Caesar shift has only 25 possible keys and Base64 isn't encryption at all — it's an encoding anyone can reverse instantly. Use these for puzzles or obfuscation, not for protecting anything sensitive.
No. Both encode and decode happen entirely in your browser.
It shifts the 26 ASCII letters only — Vietnamese diacritic letters, numbers, and punctuation pass through unchanged.
Yes — encoding and decoding go through UTF-8 bytes correctly, so Vietnamese text and emoji round-trip without corruption.
You'll see a clear error message rather than garbled output.