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SHA256 Hash Generator - The Secure Choice, Free

Generate SHA256 hashes from text or files, verify integrity, visualize the avalanche effect, run HMAC-SHA256 for API signing, and batch-hash multiple inputs - all in your browser, nothing uploaded.

Always Free ✅ Secure algorithm File hashing Runs in browser
Text · File · Batch · HMAC · Avalanche · Identicon
✅ Secure - SHA256 has no known practical attacks
Hash any file client-side - nothing ever uploaded
HMAC-SHA256 - used by AWS, Stripe, and JWT
SHA256 is the recommended algorithm for new projects - 256-bit hash, no known practical attacks, used by AWS, Bitcoin, TLS, and JWT.
Input text
0 chars
SHA256 Secure - recommended
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Algorithm comparison
AlgorithmBitsHex lengthSpeedSecurity
MD512832Fastest⚠️ Broken
SHA116040Fast⚠️ Deprecated
SHA256 ← you are here25664Fast✅ Secure - recommended
SHA512512128Medium✅ Secure - high security

What makes it different

Every other SHA256 tool
does one thing. This does ten.

File hashing, verification, avalanche visualization, HMAC, batch processing, format detection, identicons, and hash chains - all free, all in your browser.

The secure standard

SHA256 has no known practical attacks. It is the algorithm behind Bitcoin, AWS Signature V4, TLS certificates, and most modern security systems.

✅ recommended algorithm

Client-side file hashing

Hash any file directly in your browser - any size. MD5, SHA1, and SHA256 all computed simultaneously with a live progress bar.

your files stay private

HMAC-SHA256

Generate HMAC-SHA256 - used by AWS, Stripe, GitHub webhooks, and JWT HS256. Test your webhook verification logic directly here.

AWS · Stripe · JWT

Hash verification mode

Paste text and an expected SHA256 hash - instant ✅ match or ❌ no-match result with how many characters differ.

integrity confirmed

Avalanche visualizer

Change one character and watch all 64 characters of the SHA256 hash change - each difference highlighted in red.

educational, shareable

Hash identicon

Every SHA256 hash generates a unique downloadable pixel identicon - useful for visualizing uniqueness or just for fun.

visual fingerprint

Quick guide

Generate SHA256 hashes in seconds

1

Choose your mode

Text for quick hashing, File for large files (progress shown), Verify for integrity checks, HMAC for API signing.

2

Type, paste, or drop

Hash updates live as you type. Drop any file for client-side hashing - progress bar shows live status, nothing is uploaded.

3

Copy, verify, or explore

Copy the 64-character hash, verify against an expected value, sign a webhook payload with HMAC, or explore the avalanche effect.

SHA256 - why it became the standard

SHA256 is part of the SHA-2 family, designed by the NSA and published by NIST in 2001. It produces a 256-bit (64 hexadecimal character) hash using a Merkle–Damgård construction with 64 rounds of compression. Unlike MD5 and SHA1, SHA256 has no known practical attacks and remains the recommended algorithm for most hashing use cases.

Where SHA256 is used

Bitcoin uses SHA256 twice (SHA256d) for mining and transaction hashing. TLS/HTTPS certificates use SHA256 for their signature algorithm (replacing the deprecated SHA1). AWS Signature Version 4 uses HMAC-SHA256 to sign API requests. JWT tokens with the HS256 algorithm use HMAC-SHA256. Git is transitioning from SHA1 to SHA256 for object hashing. Code signing for macOS, Windows, and Android apps uses SHA256.

HMAC-SHA256 for Stripe webhooks: Stripe signs webhook payloads with HMAC-SHA256 using your webhook endpoint's secret key. To verify: concatenate the timestamp and payload with a dot, compute HMAC-SHA256 using your secret, and compare the result to the signature in the Stripe-Signature header. This tool's HMAC tab lets you test this directly.

SHA256 vs SHA512

SHA512 produces a 512-bit (128 hex character) hash and is marginally slower on 32-bit systems but actually faster than SHA256 on 64-bit hardware due to wider word operations. SHA512 is preferred for very high-security needs or when future-proofing against advances in computing. For most applications today, SHA256 offers the right balance of security and performance.

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FAQ

SHA256 questions,
answered.

Everything about SHA256 - security, use cases, and how it compares.

Ask a question
SHA256 is a cryptographic hash function from the SHA-2 family. It produces a 256-bit (64 hexadecimal character) hash. It is fast, secure, and the current standard for digital signatures, file integrity, blockchain, and API authentication. It has no known practical attacks.
SHA256 is not recommended for password hashing because it is too fast - billions of SHA256 hashes can be computed per second on modern hardware, making brute-force feasible. For passwords, use bcrypt, scrypt, or Argon2, which are designed to be slow and memory-intensive.
HMAC-SHA256 is used by AWS Signature Version 4 for API request signing, Stripe and GitHub for webhook payload verification, JWT HS256 tokens, and most modern API authentication systems. It combines SHA256 with a secret key to produce an unforgeable authentication code.
Bitcoin uses SHA256 twice (double SHA256) for its proof-of-work mining algorithm - miners must find an input whose double SHA256 hash starts with a certain number of zeros. It is also used to hash transaction data into Merkle trees, and to hash block headers.
No. File hashing uses the Web Crypto API built into your browser and runs entirely client-side. Your files are never sent to any server. You can even use this tool offline once the page has loaded.
SHA256 produces a 256-bit (64 hex char) hash; SHA512 produces a 512-bit (128 hex char) hash. Both are secure with no known practical attacks. SHA512 is faster on 64-bit hardware due to wider word operations, but SHA256 is the more widely supported and recommended choice for most applications.