Interactive calculators for classical ciphers, encodings and RSA. Each one shows its working step by step, so you can see how the result is reached as well as what it is. They come from CryptoWeb, a cryptography learning app I’m building.

Everything runs in your browser. Nothing you type is sent anywhere. These are learning tools, not secure encryption: never use them to protect real data.

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Notes

• Row transposition comes in two key conventions. Some sources write the key as the order the columns are read (3142 → read column 3, then 1, 4, 2). Textbooks often write the rank of each column instead. Pick the one that matches your material.
• RSA uses arbitrary-precision integers, so large numbers work. Key generation checks that p and q are prime and that e is coprime with φ(n).
• XOR shows each byte in binary. Choose Hex input to decrypt hex output back to text.

Want to try CRC as well? See the CRC-8 calculator.