SHA-256 Hash Generator
Cryptographic hashing with SHA-256, SHA-384, and SHA-512.
SHA-256 in Modern Cryptography
SHA-256 is one of the most widely deployed cryptographic hash functions in the world. It powers critical infrastructure including:
- Bitcoin and blockchain: SHA-256 is the proof-of-work algorithm behind Bitcoin mining and block verification.
- TLS/SSL certificates: Modern certificates use SHA-256 signatures (after SHA-1 was deprecated in 2017).
- Code signing: Software packages, OS updates, and container images are signed with SHA-256 digests.
- Git: Git is migrating from SHA-1 to SHA-256 for commit hashing.
SHA-1 vs SHA-256 vs SHA-3
| Property | SHA-1 | SHA-256 | SHA-3 (256) |
|---|---|---|---|
| Output size | 160 bits | 256 bits | 256 bits |
| Security status | Broken (2017) | Secure | Secure |
| Collision resistance | ~60 bits | 128 bits | 128 bits |
| Speed (software) | Fast | Fast | Moderate |
| Design | Merkle-Damgård | Merkle-Damgård | Sponge (Keccak) |
| Adoption | Legacy only | Dominant | Growing |
When to Use SHA vs bcrypt
SHA-256 is a general-purpose hash: fast, deterministic, and designed for data integrity. bcrypt is a password-specific hash: intentionally slow and salted.
Use SHA-256 for: file checksums, digital signatures, HMACs, blockchain, and data integrity. Use bcrypt (or Argon2) for: storing user passwords, where you need brute-force resistance.
Frequently Asked Questions
What is SHA-256?
SHA-256 (Secure Hash Algorithm 256-bit) is a cryptographic hash function from the SHA-2 family, designed by the NSA. It produces a 256-bit (64-character hexadecimal) digest from any input. SHA-256 is used in TLS/SSL, Bitcoin, code signing, and digital certificates.
Is SHA-256 secure?
Yes. As of 2024, no practical collision or preimage attacks against SHA-256 exist. It remains approved by NIST for all cryptographic applications. SHA-256 provides 128 bits of collision resistance, which is considered secure for the foreseeable future.
What is the difference between SHA-256, SHA-384, and SHA-512?
All three belong to the SHA-2 family. SHA-256 uses 32-bit words and outputs 256 bits. SHA-512 uses 64-bit words and outputs 512 bits — it's actually faster than SHA-256 on 64-bit processors. SHA-384 is a truncated version of SHA-512. Choose SHA-256 for general use and SHA-512 for maximum security.
Should I use SHA-256 for password hashing?
No. SHA-256 is a fast hash — it can compute billions of hashes per second on a GPU, making brute-force attacks feasible. For passwords, use a slow hash like bcrypt, scrypt, or Argon2 that is intentionally expensive to compute.
How does this tool compute the hash?
This tool uses the Web Crypto API (crypto.subtle.digest) built into your browser. It is a native, hardware-accelerated implementation. Your text is never sent to any server — all hashing happens locally in your browser.