Question 1

What is NumbersChecker?

Accepted Answer

NumbersChecker is a free online toolbox with 139+ utilities for decoding ciphers, solving puzzles, hashing strings, encoding data, number theory, math, text analysis, and science. No login or installation required.

Question 2

Is NumbersChecker free to use?

Accepted Answer

Yes, all 139+ tools on NumbersChecker are completely free. No account, subscription, or installation is required.

Question 3

What cipher tools are available?

Accepted Answer

NumbersChecker offers 25 cipher tools including Caesar cipher decoder, Vigenère cipher, ROT13, Atbash, Morse code, Base64, Binary, Hex, A1Z26, Rail Fence, Affine, Polybius Square, Scytale, Columnar Transposition, and more.

Question 4

Can I use NumbersChecker to solve puzzles?

Accepted Answer

Yes. NumbersChecker includes 12 puzzle tools including a Wordle solver, Hangman solver, Crossword pattern finder, Kakuro clue calculator, Scrabble word builder, substitution cipher solver, and number sequence solver.

Question 5

Does NumbersChecker have an API?

Accepted Answer

Yes. Every tool is available as a free JSON REST API. Send a POST request to https://numberschecker.com/api/{toolId} with your input as JSON. No authentication required.

Question 6

What hashing tools are available?

Accepted Answer

NumbersChecker provides MD5, SHA-1, SHA-256, SHA-512, and CRC32 hash generators, plus a hash identifier tool that detects the likely algorithm used for any given hash string.

Question 7

How do I decode a Caesar cipher?

Accepted Answer

Go to https://numberschecker.com/tool/caesar, enter your ciphertext, and set the shift amount. The tool also shows a brute-force table of all 26 possible shifts so you can spot the correct decoding at a glance.

Question 8

What number tools are available?

Accepted Answer

NumbersChecker has 15 number tools including a base converter (binary, octal, hex, and any base 2–36), Roman numeral converter, prime factorization, GCD and LCM calculator, Fibonacci generator, Euler totient, Chinese Remainder Theorem solver, and number-to-words converter.

Science Tools — 7 tools

Science

Periodic Table Lookup

Resistor Color Code

BMI Calculator

Speed / Distance / Time

Ohm's Law Calculator

pH Calculator

Molecular Weight