SHA-256 Hash Generator
Generate a SHA-256 checksum from any text or file — instantly, for free. Your data never leaves your browser. Uses the Web Crypto API for cryptographically secure, native-speed hashing.
SHA-256 is cryptographically secure
SHA-256 is the modern standard for file checksums, digital signatures, and HMAC authentication. It is part of the SHA-2 family and is approved by NIST for use in federal information processing.
HMAC mode
Generate keyed-hash message authentication codes
Drop a file here, or browse
Any file type, up to 2 GB. Never uploaded.
What is SHA-256?
SHA-256 (Secure Hash Algorithm 256-bit) is a member of the SHA-2 cryptographic hash function family, published by NIST in 2001. It produces a fixed-length 256-bit (64 hexadecimal character) digest from any input, regardless of size. Unlike MD5, no practical collision attacks against SHA-256 are known.
SHA-256 is used pervasively in modern security infrastructure: TLS/SSL certificates, code-signing, SSH keys, GPG signatures, Bitcoin's proof-of-work algorithm, and the majority of HMAC implementations in REST APIs and webhook verification. If a system requires a cryptographic hash today, SHA-256 is the safe default.
This generator computes SHA-256 using the browser's native Web Crypto API — the same cryptographic primitives used by your browser for TLS. No JavaScript library is involved; the computation is performed at native speed entirely on your device.
Common SHA-256 use cases
SHA-256 file checksum verification
Verify a downloaded file
Drop your downloaded file into the File tab to get its SHA-256 checksum. Compare it to the SHA-256 published by the software author using the Hash Comparison box on the homepage. A green check confirms the file was not corrupted or tampered with.
HMAC-SHA-256 API signing
Sign API requests
Many REST APIs (AWS Signature V4, Stripe webhooks, GitHub webhooks) require HMAC-SHA-256 signatures. Enable HMAC mode above and enter your secret key to generate an HMAC-SHA-256 signature without any command-line tools.
SHA-256 webhook verification
Verify webhook payloads
Services like GitHub, Stripe, and Shopify sign webhook payloads with HMAC-SHA-256 using a shared secret. Use HMAC mode to recompute the signature and confirm the payload has not been tampered with.
SHA-256 content fingerprint
Generate content fingerprints
SHA-256 produces a deterministic fingerprint for any input. Use it to detect duplicate files, verify data integrity in pipelines, or create Subresource Integrity (SRI) hashes for CDN-hosted scripts.
SHA-256 frequently asked questions
What is a SHA-256 hash?
SHA-256 (Secure Hash Algorithm 256-bit) is part of the SHA-2 family designed by the NSA. It produces a fixed-length 256-bit (64 hexadecimal character) hash from any input. SHA-256 is cryptographically secure and is the modern standard for file checksums, digital signatures, TLS certificates, and blockchain proof-of-work.
Is SHA-256 safe to use for passwords?
SHA-256 alone is not recommended for password hashing because it is too fast — an attacker can compute billions of SHA-256 hashes per second using GPUs. For passwords, use a purpose-built slow hashing function such as bcrypt, scrypt, or Argon2. SHA-256 is excellent for file integrity, digital signatures, and HMAC authentication.
How do I generate a SHA-256 hash online?
Paste your text into the input above — the SHA-256 hash appears instantly in the output panel. To hash a file, click the File tab and drop your file. The SHA-256 checksum is generated entirely in your browser using the Web Crypto API; nothing is uploaded to any server.
Can I generate SHA-256 from a file without uploading it?
Yes. The File tab reads your file using the browser's FileReader API and hashes it locally with the Web Crypto API. Files up to 2 GB are supported. No data ever leaves your device.
What is the difference between SHA-256 and SHA-512?
SHA-256 produces a 64-character hex digest (256 bits); SHA-512 produces a 128-character hex digest (512 bits). SHA-512 offers a larger output but is not necessarily more secure for most use cases. SHA-512 can actually be faster than SHA-256 on 64-bit processors because it performs operations on 64-bit words. For most applications SHA-256 is the right choice.
How do I verify a SHA-256 checksum on Windows or macOS?
On macOS, run in Terminal: shasum -a 256 /path/to/file. On Windows PowerShell: Get-FileHash C:\path\to\file -Algorithm SHA256. Alternatively, drop the file into the File tab here and paste the expected checksum into the Hash Comparison box on the homepage for an instant match check.
What is HMAC-SHA-256?
HMAC-SHA-256 (Hash-based Message Authentication Code) combines a secret key with SHA-256 to produce a message authentication code. It is used to verify both the integrity and authenticity of a message. Common uses include API request signing, JWT tokens, and webhook payload verification. Enable HMAC mode above and enter your secret key to generate an HMAC-SHA-256.