Free Cryptography Tools
Hash data, encrypt files, generate keys, verify checksums, and explore classical ciphers. Every tool uses the Web Crypto API, requires no signup, and processes data 100% client-side.
Why Use Online Cryptography Tools?
Cryptography is fundamental to modern software development. From password hashing to file integrity verification, from API authentication to secure communications, developers need reliable crypto tools daily. Running these operations in the browser using the Web Crypto API means your sensitive data never leaves your device - no server processing, no logging, and no third-party risk.
Generate Hashes Instantly
The Hash Generator computes SHA-256, SHA-384, SHA-512, SHA-1, and MD5 hashes of any text input. The Text Hash Compare tool lets you verify whether two pieces of text produce the same hash, useful for detecting even single-character differences. The Hash Identifier analyzes an unknown hash string and identifies its probable algorithm based on length and character patterns.
Encrypt and Decrypt Data
The AES Encryption tool performs AES-256-GCM encryption using the Web Crypto API. It derives keys from passwords using PBKDF2 with a random salt and provides authenticated encryption that protects both confidentiality and integrity. This is the same encryption standard used by governments and financial institutions worldwide.
Generate Cryptographic Keys
The RSA Key Generator creates 2048-bit and 4096-bit RSA key pairs in PEM format, ready for use with SSH, SSL/TLS, and code signing. The BIP39 Mnemonic Generator creates standard 12-word and 24-word seed phrases for cryptocurrency wallets using cryptographically secure random number generation.
Verify File Integrity
The File Checksum Verifier computes SHA-256 hashes of files directly in your browser to verify downloads have not been tampered with. Drag and drop any file and compare the calculated hash against the expected value provided by the software publisher. All processing happens locally - the file is never uploaded.
HMAC and Password Hashing
The HMAC Generator creates Hash-based Message Authentication Codes for API request signing, webhook verification, and message integrity. The Password Hasher (PBKDF2) demonstrates secure password hashing with configurable iterations, producing salted hashes suitable for authentication systems.
Classical Ciphers for Education
The ROT13 / ROTn Cipher and Caesar Cipher implement the simplest substitution ciphers, valuable for learning cryptographic fundamentals. The collection also includes visual and esoteric encoding systems like the Colored Squares Cipher, Five-Needle Telegraph, Clock Code Decoder, and Gallifreyan Symbol Generator for creative and educational exploration.
Frequently Asked Questions
What is the difference between hashing and encryption?
Hashing is a one-way function that produces a fixed-length digest from any input - you cannot reverse a hash to get the original data. It is used for password storage, file integrity verification, and digital signatures. Encryption is a two-way function that transforms data using a key, and the original data can be recovered with the correct decryption key. Use hashing when you need to verify data without storing it, and encryption when you need to protect data that must be retrieved later.
What hash algorithms are available?
The Hash Generator supports SHA-1, SHA-256, SHA-384, SHA-512, and MD5 using the Web Crypto API built into your browser. SHA-256 is the most widely used for general purposes. MD5 and SHA-1 are considered weak for security applications but are still used for non-cryptographic checksums. The tool also supports HMAC variants for keyed hashing.
How does AES encryption work in the browser?
Our AES Encryption tool uses the Web Crypto API to perform AES-256-GCM encryption entirely in your browser. GCM (Galois/Counter Mode) provides both confidentiality and integrity. You provide a password, and the tool derives a 256-bit key using PBKDF2 with a random salt. The encrypted output includes the salt, initialization vector, and ciphertext encoded in Base64.
What is a BIP39 mnemonic seed phrase?
BIP39 is a standard for generating cryptocurrency wallet seed phrases as a sequence of 12 or 24 common English words. Each word maps to a number in a standardized 2048-word list. The mnemonic encodes entropy plus a checksum, making it easier to back up and restore wallets than writing down raw hexadecimal keys. Our generator creates valid BIP39 mnemonics using cryptographically secure random number generation.
Is it safe to use browser-based cryptography tools?
Yes, when the tools use the Web Crypto API as ours do. The Web Crypto API is a native browser standard that provides cryptographically secure operations. All processing happens locally on your device with no data transmitted to servers. For maximum security, you can disconnect from the internet before using these tools, or verify in your browser's developer tools that no network requests are made.