SHA-256 generator

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Create a SHA-256 hash online from any text or file. This SHA-256 generator produces a fixed 256-bit digest represented as a 64-character hexadecimal string. It’s widely used for file integrity verification, blockchain applications, digital signatures, and secure password hashing (when combined with salt and KDFs). Typical long-tail uses include SHA-256 checksum verification, SHA-256 hash of a string, and calculate SHA-256 of a file online.

What is SHA-256?

SHA-256 (Secure Hash Algorithm 256-bit) is part of the SHA-2 family standardized by NIST. It produces a unique fingerprint for any input while being computationally infeasible to reverse or find collisions. SHA-256 is the foundation of Bitcoin mining, TLS/SSL certificates, and many modern authentication systems.

How to use the SHA-256 Generator

  1. Enter text or upload a file to hash.
  2. Click Generate to compute the SHA-256 digest.
  3. Copy the 64-character hex output and compare with known checksums or store it safely.

When should you use it?

  • File verification: Ensure downloads are intact by matching the publisher’s SHA-256 checksum.
  • Digital signatures: Input to RSA/ECDSA signing for tamper-evident messages.
  • Blockchain: SHA-256 is core to Bitcoin block hashing and transaction IDs.
  • Password security: Use SHA-256 with salting and KDFs like PBKDF2, Argon2, or bcrypt for safe storage.

Who is this for?

  • Developers generating secure hashes for APIs, tokens, or checksums.
  • System administrators validating server binaries and configuration integrity.
  • Blockchain engineers working with Bitcoin or SHA-256–based cryptocurrencies.
  • Researchers & students studying cryptographic hash functions.

Best practices & caveats

  • Never store plain SHA-256 hashes for passwords: Always add salt and use a KDF (e.g., Argon2, bcrypt, PBKDF2).
  • Exact match required: Even a 1-bit change in input gives a completely different output (avalanche effect).
  • Always check encoding: UTF-8 vs UTF-16 and line endings (\n vs \r\n) will change the hash.
  • Publish multiple checksums: Sometimes paired with SHA-512 for broader compatibility.

Examples

SHA-256 of a string

Input:  "hello world"
Output: b94d27b9934d3e08a52e52d7da7dabfac484efe37a5380ee9088f7ace2efcde9

SHA-256 of a file (command-line reference)

# macOS/*nix
shasum -a 256 /path/to/file

# Linux
sha256sum /path/to/file

# Windows PowerShell
Get-FileHash -Algorithm SHA256 "C:\path\to\file"

FAQ

Can SHA-256 be decrypted?

No. SHA-256 is a one-way function. “Decryption” sites only check against precomputed databases or rainbow tables.

Why is SHA-256 widely trusted?

It’s part of the SHA-2 family, standardized and vetted by NIST, with no practical collisions found to date. It is considered secure for modern use.

Why doesn’t my hash match?

Check that you used the exact same input data, encoding, and file format. Even hidden characters or different encodings will change the digest.

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