Hash Generator
Generate MD5, SHA-1, SHA-256, and SHA-512 hashes from any text instantly. Everything runs in your browser.
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Quick Reference — Hash Algorithm Comparison
| Algorithm | Output Size | Hex Length | Security |
|---|---|---|---|
| MD5 | 128 bits | 32 chars | Broken (collisions found) |
| SHA-1 | 160 bits | 40 chars | Deprecated (collisions found) |
| SHA-256 | 256 bits | 64 chars | Secure (current standard) |
| SHA-512 | 512 bits | 128 chars | Secure (highest strength) |
What is Hashing?
A hash function is a mathematical algorithm that takes an input (or “message”) of any size and produces a fixed-size string of bytes, typically displayed as hexadecimal characters. The output is called a hash, digest, or checksum. Key properties: the same input always produces the same hash, even a tiny change produces a completely different hash (avalanche effect), and it is computationally infeasible to reverse a hash back to its original input.
MD5 vs SHA-1 vs SHA-256 vs SHA-512
MD5 (Message Digest 5) produces a 128-bit hash. It is fast but cryptographically broken — collision attacks have been demonstrated since 2004. It should not be used for security purposes but is still common for non-security checksums.
SHA-1 (Secure Hash Algorithm 1) produces a 160-bit hash. It was the standard for many years but was deprecated in 2017 after Google demonstrated a practical collision. Most browsers and certificate authorities no longer trust SHA-1.
SHA-256 is part of the SHA-2 family and produces a 256-bit hash. It is the current industry standard used in TLS certificates, Bitcoin mining, digital signatures, and password hashing. No practical attacks are known.
SHA-512 also belongs to the SHA-2 family, producing a 512-bit hash. It offers higher security margins and can be faster than SHA-256 on 64-bit processors.
Hashing vs Encryption
Hashing is one-way — you cannot reverse a hash back to the original data. Encryption is two-way — encrypted data can be decrypted with the correct key. Hashing is used for integrity verification and password storage. Encryption is used for confidentiality (protecting data in transit or at rest).
Common Use Cases
Password storage: Applications hash passwords before storing them so the original password is never saved.
File integrity: Download sites publish checksums so you can verify the file was not corrupted or tampered with.
Digital signatures: The document is hashed and the hash is signed, which is faster than signing the entire document.
Blockchain: Bitcoin and other cryptocurrencies use SHA-256 for mining and transaction verification.
Frequently Asked Questions
- What is a hash function?
- A one-way mathematical function that converts any input into a fixed-size string. The same input always produces the same hash, but you cannot reverse a hash back to the original data.
- What is the difference between MD5 and SHA-256?
- MD5 produces a 128-bit (32-character) hash and is broken for security use. SHA-256 produces a 256-bit (64-character) hash and is the current secure standard.
- Is MD5 still secure?
- No. MD5 has known collision vulnerabilities. It should not be used for passwords, signatures, or certificates. It is still acceptable for non-security checksums.
- How do I generate a SHA-256 hash online?
- Type or paste your text into this tool and select SHA-256. The hash is generated instantly in your browser using the Web Crypto API.
- What is hashing used for?
- Password storage, file integrity checksums, digital signatures, blockchain mining, data deduplication, and caching.