Yes. No practical collisions have ever been found in SHA-256. It's the modern default for digital signatures, TLS certificates, and blockchain systems. Grover's algorithm on a quantum computer could theoretically halve its effective security, but that's far from practical.

Why is SHA-256 used in Bitcoin?

Bitcoin uses double-SHA-256 (SHA-256 of SHA-256) for transaction IDs, block hashes, and proof-of-work. The choice was made when Bitcoin was designed in 2008 for its strong collision resistance and wide hardware support.

Can I use SHA-256 for passwords?

Not directly. SHA-256 is too fast — a GPU can try billions per second, which makes brute-force attacks easy. For password hashing use Argon2id, bcrypt, or scrypt, which are slow on purpose.

How fast is SHA-256 in the browser?

The Web Crypto API is backed by native code (typically OpenSSL-equivalent), so a modern laptop hashes 500 MB in under 2 seconds. Much faster than pure-JS implementations.

Does SHA-256 output depend on line endings?

Yes. \r\n and \n produce different hashes. If you're comparing with a hash from a different operating system, normalise line endings first (or re-hash the file in binary mode).

Why 256 bits specifically?

256 bits gives ~128 bits of collision resistance (after a birthday attack), which matches the strength of AES-128. Bigger than 256 costs speed and space without meaningful security gain; smaller is cryptanalytically risky over time.

SHA256 Hash Generator

Compute SHA-256 digests for integrity checks and signing.

SHA-256 runs in your browser via Web Crypto. Text and files never upload.

SHA-256 · 256-bit digest · the modern default for integrity and signatures

Text input

Hash each line separately

SHA-256 hash

—

0 chars · lowercase hex

File input

Hash any file up to 500 MB. Processed locally — the file never uploads.

Click to pick a file

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What is a SHA-256 Hash Generator?

SHA-256 is the 256-bit member of the SHA-2 family of cryptographic hash functions, published by the US National Institute of Standards and Technology (NIST) in 2001. Given any input of any length, it produces a 64-character hexadecimal digest that is — for all practical purposes — unique. Unlike MD5 and SHA-1, no practical collision has ever been found in SHA-256. It is the modern default for digital signatures, TLS/SSL certificates, blockchain proof-of-work, JWT signing, and any system where integrity and authenticity matter.

Why 256 bits? Because 2²⁵⁶ is astronomical — about 10⁷⁷ — more than the estimated number of atoms in the observable universe. Even with a birthday attack (which halves the effective security), finding a SHA-256 collision would require around 2¹²⁸ operations. At current computing speeds, that is thousands of years of planet-wide GPU effort. Quantum computing reduces this to 2⁸⁵ via Grover's algorithm, which is still far outside practical reach.

Everyday uses you probably touch without realising. Bitcoin and most other cryptocurrencies use SHA-256 (usually double-SHA-256) for proof-of-work and transaction IDs. TLS certificates use SHA-256 in their signatures; your browser's padlock icon is validating a SHA-256 signature every time. JWT tokens signed with HS256 use HMAC-SHA-256. File-integrity verification on software downloads — Ubuntu, Debian, Node.js, Python releases all publish SHA-256 checksums. Git is slowly migrating its object IDs from SHA-1 to SHA-256 for the same reason.

Password storage is a subtle case. SHA-256 is too fast for password hashing — a modern GPU can compute billions of SHA-256 hashes per second, which is exactly what you donot want when defending against brute-force password guessing. For password storage, use a purpose-built slow hash: Argon2id is the modern default, bcrypt is the long-standing safe choice, scrypt is another option. SHA-256 itself is used inside those schemes as a building block, but wrapped with thousands of iterations and a salt.

This generator uses the browser's native crypto.subtle.digest("SHA-256") API. Text is hashed as UTF-8 bytes for consistency with sha256sum, openssl dgst -sha256, Python's hashlib.sha256, Node.js's crypto.createHash("sha256"), and every other standard SHA-256 implementation. Files are hashed directly from an ArrayBuffer with zero upload.

How to generate a SHA-256 hash

Paste text or pick a file. Any length, any content.
Pick hex or Base64. 64 hex chars or 44 Base64 chars.
Copy the hash. Verify against a published reference.
Integrity check. Send the hash over a separate channel so the recipient can re-hash and confirm nothing changed in transit.

Features

Native Web Crypto implementation — fast and fully standard-compliant.
Text and file hashing with no upload (500 MB file cap).
Hex or Base64 output.
UTF-8 text encoding matches command-line and server-side SHA-256 tools.

Frequently asked questions

Is SHA-256 safe?: Yes. No practical collisions have ever been found in SHA-256. It's the modern default for digital signatures, TLS certificates, and blockchain systems. Grover's algorithm on a quantum computer could theoretically halve its effective security, but that's far from practical.
Why is SHA-256 used in Bitcoin?: Bitcoin uses double-SHA-256 (SHA-256 of SHA-256) for transaction IDs, block hashes, and proof-of-work. The choice was made when Bitcoin was designed in 2008 for its strong collision resistance and wide hardware support.
Can I use SHA-256 for passwords?: Not directly. SHA-256 is too fast — a GPU can try billions per second, which makes brute-force attacks easy. For password hashing use Argon2id, bcrypt, or scrypt, which are slow on purpose.
How fast is SHA-256 in the browser?: The Web Crypto API is backed by native code (typically OpenSSL-equivalent), so a modern laptop hashes 500 MB in under 2 seconds. Much faster than pure-JS implementations.
Does SHA-256 output depend on line endings?: Yes. \r\n and \n produce different hashes. If you're comparing with a hash from a different operating system, normalise line endings first (or re-hash the file in binary mode).
Why 256 bits specifically?: 256 bits gives ~128 bits of collision resistance (after a birthday attack), which matches the strength of AES-128. Bigger than 256 costs speed and space without meaningful security gain; smaller is cryptanalytically risky over time.