Online cipher tools

Encrypt and decrypt classical ciphers or convert text to UTF-8. Each tool sits next to an explanation of the algorithm. Everything runs in your browser – the text you enter is not sent anywhere.

• Playfair cipher online

  Digraph substitution with a 5×5 table built from a keyword.

• Two-square cipher online

  Two key tables, horizontal or vertical layout.

• Four-square cipher online

  Four 5×5 tables, two of them built from keywords.

• Rail fence cipher online

  Zigzag transposition with a chosen number of rails and offset.

• Route cipher online

  Text written into a grid and read along a spiral.

• UTF-8 converter online

  Text ↔ UTF-8 bytes as hex, binary, decimal or HTML entities.