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Text Encrypt & Decrypt

Caesar, ROT13, Vigenere, AES-256, Atbash, Morse Code, Base64 — all in your browser

Choose Algorithm

Algorithms

  • Caesar cipher
  • ROT13
  • Vigenere cipher
  • Atbash cipher
  • AES-256-GCM
  • Base64 encode/decode
  • Morse code
  • Binary & Hex encode
  • Text reverse

Security Note

  • AES-256 is truly secure
  • Others are educational
  • Caesar/ROT13 = weak
  • All processing in browser

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Free Text Encryption & Decryption Tool

Encrypt and decrypt text using 10 different algorithms ranging from classical ciphers (Caesar, Vigenere, Atbash, ROT13) to modern AES-256-GCM military-grade encryption — all running locally in your browser using the native Web Crypto API. No data ever leaves your device.

Features

AES-256-GCM

Military-grade encryption using the browser's native Web Crypto API with PBKDF2 key derivation.

Morse Code

Encode and decode text to and from Morse code dots and dashes.

Base64 Encoding

Encode and decode Base64 — essential for data transmission and embedding.

ROT13

Classic ROT13 — applying it twice returns the original. Widely used to hide spoilers.

Vigenere Cipher

A polyalphabetic substitution cipher — significantly stronger than Caesar.

Atbash Cipher

Ancient Hebrew cipher that reverses the alphabet (A↔Z, B↔Y).

Who Uses This Tool?

DevelopersEncode data in Base64 for APIs, embed in HTML, or debug JWT tokens.
Puzzle EnthusiastsSolve and create classical cipher challenges and cryptography puzzles.
StudentsLearn the history and mechanics of classical cryptography in an interactive way.
Privacy-Conscious UsersEncrypt sensitive notes with AES-256 before storing in cloud services.

Frequently Asked Questions

Which algorithm should I use for real security?
Only AES-256-GCM provides genuine security. All classical ciphers (Caesar, ROT13, Vigenere, Atbash) are trivially breakable and should be used only for educational purposes or obfuscation.
How secure is AES-256-GCM?
AES-256-GCM is effectively unbreakable with current technology. It is used by governments, banks and militaries worldwide. The security depends entirely on the strength of your password — use a long, random passphrase.
What is Base64 and is it encryption?
Base64 is an encoding scheme, not encryption. It converts binary data to ASCII text for safe transmission. It provides no security — anyone can decode it instantly. Never use it to "hide" sensitive information.
Can I decrypt text encrypted with a different tool?
AES-256 is a standard, but implementation details (IV, padding, key derivation) vary between tools. Text encrypted with our tool can only be reliably decrypted with our tool due to our specific PBKDF2 + GCM implementation.

Pro Tip

For AES-256 encryption, use a strong passphrase of at least 20 characters — ideally a phrase with mixed case, numbers and symbols. A weak password is the most common way AES encryption is defeated, not the algorithm itself.

Did You Know?

58 BC
Caesar Cipher Used in War
Julius Caesar used a simple letter-shift cipher in his military communications around 58 BC. He typically shifted letters by 3 positions. ROT13 (shift by 13) is a modern variant — applying it twice returns the original text.
AES-256
Protects Everything You Know
AES-256 encryption protects your bank transactions, HTTPS web connections, WhatsApp messages, iPhone backups and classified government communications. It has been the global encryption standard since 2001.
2^256
AES-256 Key Combinations
AES-256 has 2^256 possible keys. Even if every atom in the observable universe were a computer running since the Big Bang, it couldn't brute-force AES-256 by the time the universe ends. Security comes entirely from your password strength.

Cipher Strength Comparison

CipherTypeKey SpaceCrack TimeUse Today
Caesar (shift 3)Classical26 keysMillisecondsEducational only
ROT13Classical1 keyInstantSpoiler hiding only
VigenerePolyalphabeticLargeHours/daysEducational, puzzles
Base64EncodingNoneInstantData transfer, not security
AES-128Modern symmetric2^128Effectively neverGeneral security
AES-256Modern symmetric2^256Never (quantum-safe)High-security data

More Questions

What makes AES-256 quantum-resistant?
Quantum computers using Grover's algorithm can theoretically halve effective key length — reducing AES-256 to ~128-bit equivalent security. AES-128 would drop to ~64-bit, which may be breakable. This is why NIST recommends AES-256 for long-term data protection in a post-quantum world. Our AES-256 implementation provides this higher security level.
What is the difference between symmetric and asymmetric encryption?
Symmetric encryption (AES) uses the same key to encrypt and decrypt — fast, ideal for large data, but requires secure key exchange. Asymmetric encryption (RSA, ECC) uses a public key to encrypt and a private key to decrypt — solves key exchange but is 1,000× slower. HTTPS uses asymmetric to exchange a symmetric key, then AES for the actual data — combining both advantages.
How does Morse Code work and is it still used?
Morse code represents letters as sequences of dots (·) and dashes (−), originally transmitted as short and long electrical pulses. Created by Samuel Morse in 1838, it was the world's first digital communication system. It's still used by amateur radio operators, military and aviation (radio beacons still broadcast their identifier in Morse). SOS (···−−−···) is universally recognized.

Common Mistakes

Thinking Base64 is encryption
Base64 is encoding — it has no key and anyone can decode it instantly. It converts binary to text for safe transmission.
Use AES-256 for actual security. Base64 is for data format, not confidentiality.
Using a weak password with AES-256
AES-256 is unbreakable, but "password123" as your key is not. The encryption is only as strong as the passphrase protecting it.
Use our Password Generator to create a 20+ character random passphrase for AES keys.
Assuming ROT13 provides security
ROT13 is the digital equivalent of "pig latin" — any child with 5 minutes and the alphabet can decode it.
Use ROT13 only for hiding spoilers. For any real privacy, use AES-256.