SHA-256 Online Hash Generator
Use our secure SHA-256 hash generator to convert any string into a 64-character hexadecimal hash value. This free, browser-based tool instantly computes the SHA-256 checksum of your input without sending data to a server — your data never leaves your device.
What is SHA-256?
SHA-256 (Secure Hash Algorithm 256-bit) is part of the SHA-2 family, standardized by NIST in 2001. It produces a 256-bit (64 hexadecimal character) hash and is one of the most widely deployed cryptographic hash functions in the world.
SHA-256 powers some of the most critical infrastructure on the internet: it is used in Bitcoin mining, TLS/SSL certificates, JWT tokens, code signing, and digital signatures. It has no known practical collision attacks and is recommended by NIST through at least 2030.
Where SHA-256 Is Used
- Bitcoin & blockchain: SHA-256 is the proof-of-work algorithm in Bitcoin mining
- HTTPS / TLS: SSL certificates use SHA-256 for digital signatures
- JWTs: HS256 and RS256 in JSON Web Tokens use SHA-256
- Code signing: Software packages are signed with SHA-256 checksums
- File integrity: Verify downloads haven't been tampered with
- Password hashing: As part of PBKDF2, when used with a salt and iterations
SHA-256 vs Other Hash Algorithms
- vs MD5: SHA-256 is far more secure — MD5 has known collisions and should not be used for security
- vs SHA-512: SHA-512 offers a longer 512-bit hash; SHA-256 is sufficient for most use cases
- vs SHA-3-256: Both produce 256-bit hashes; SHA-3 uses a different (Keccak) algorithm providing an independent security guarantee
Why Choose SHA-256?
- Strong cryptographic integrity with no known practical attacks
- Resistant to collisions, preimage, and brute-force attacks
- Universally supported across all programming languages and platforms
- Used in Bitcoin, HTTPS, JWTs, APIs, and digital certificates
- Recommended by NIST for use through 2030
How to Generate a SHA-256 Hash
- Enter your input text in the field above.
- The 64-character SHA-256 hash appears instantly.
- Choose output format: Hex, Base64, or Bytes.
- Copy the result with one click.
Frequently Asked Questions
What is SHA-256 used for?
SHA-256 is used in Bitcoin mining and blockchain technology, TLS/SSL certificates, digital signatures (code signing, document signing), HMAC authentication, JWT token verification, and secure password hashing (when used with a salt). It is one of the most widely deployed cryptographic hash functions.
Is SHA-256 secure?
Yes. SHA-256 is currently considered cryptographically secure. There are no known practical collision or preimage attacks against SHA-256. It is recommended by NIST for use through at least 2030.
What is the SHA-256 output length?
SHA-256 always produces a 256-bit hash, displayed as 64 hexadecimal characters. The output length is fixed regardless of the input size.
SHA-256 vs SHA-512: which should I use?
SHA-256 is the standard choice for most applications. SHA-512 offers a larger 512-bit output and can be faster on 64-bit systems due to architecture optimizations, but SHA-256 is sufficient for the vast majority of use cases. Use SHA-512 when you specifically need a longer hash or are targeting 64-bit hardware.
SHA-256 vs MD5: what is the difference?
SHA-256 (256-bit, 64 hex chars) is cryptographically secure with no known collisions. MD5 (128-bit, 32 hex chars) has known collision vulnerabilities and should not be used for security purposes. For new projects, always prefer SHA-256 over MD5.
Can SHA-256 be reversed?
No. SHA-256 is a one-way hash function. It is computationally infeasible to recover the original input from a SHA-256 hash. This is a fundamental cryptographic property.
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