Crack, decode, and solve classical ciphers — even without a key
Built for students who need quick cipher decryption and automatic cracking tools.
Manual Cipher Solver
Use this mode when you already know the key or shift. Select a cipher type, enter the required key, and decrypt instantly.
Auto Crack Supported
Caesar Cipher
ROT13
Atbash
Rail Fence Cipher
Affine Cipher
Manual Solve Only
Vigenère Cipher
Columnar Transposition
These ciphers require a known key and cannot be auto-cracked in this version.
0 / 5000 characters
Enter shift value (1–25). Default is 3.
Letters only (A–Z).
Enter the number of rails (2–20).
a must be coprime with 26. Valid a: 1,3,5,7,9,11,15,17,19,21,23,25
Decrypted Plaintext
Auto Crack
Use this mode when the key is unknown. Paste ciphertext and SolveX will try all supported cracking methods automatically — no key needed.
Supported Ciphers for Auto Crack
Caesar (brute force)
ROT13
Atbash
Rail Fence (brute force)
Affine (brute force)
Unknown-key Vigenère and Columnar Transposition cracking are not supported in this version. These are planned future features. Use Manual Solve if you know the key.
0 / 5000 characters
Analyzing…
Best Guess
Top Alternate Candidates
All Caesar Shifts
Letter Frequency Analysis
Bar height shows the percentage of each letter in the ciphertext. English typically peaks at E, T, A, O, I, N.
Reminder: Vigenère and Columnar Transposition were not tested above because unknown-key cracking for these ciphers is not yet supported. If you suspect your ciphertext uses one of these ciphers, switch to Manual Solve and provide the key.
Coming Soon — Advanced Cracking
These features are planned for future versions of SolveX. They are not available yet.
Current Support Summary
Cipher
Manual Solve
Auto Crack
Caesar Cipher
Supported
Supported
ROT13
Supported
Supported
Atbash
Supported
Supported
Rail Fence
Supported
Supported
Affine
Supported
Supported
Vigenère
Supported
Not Yet
Columnar Transposition
Supported
Not Yet
Unknown-Key Vigenère Cracking
Future versions may use Kasiski examination and the Index of Coincidence to estimate the keyword length, then use frequency analysis on each column to recover the key automatically. This is a complex technique that requires statistical analysis of repeating patterns in the ciphertext.
Unknown-Key Columnar Transposition Cracking
Future versions may use key-length guesses combined with permutation search and English-likeness scoring to brute-force short transposition keys. The number of permutations grows factorially, so this approach is practical only for short keys.
Frequency Analysis Dashboard
A visual tool showing letter frequency, bigram, and trigram distributions of the ciphertext to help students identify cipher types manually.
Cipher Identifier
An automatic tool that analyzes ciphertext properties (length, character set, frequency profile) and suggests the most likely cipher type before cracking.
Sample Examples
Click Try It to auto-fill with a ready-made example.
Manual — Caesar
Shift: 3
WKHUHDUHLQILQLWHOBPDQBSULPHQXPEHUV
Expected: THEREAREINFINITELYMANYPRIMENUMBERS
Auto Crack — ROT13
No key needed
GUR DHVPX OEBJA SBK WHZCF BIRE GUR YNML QBT
Expected: THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG