SHA-256 Hash Generator — Text, Files & HMAC-SHA256
Generate SHA-256 hashes and HMAC-SHA256 signatures, and verify checksums — privately in your browser.
Hash results
Quick answer
To generate a SHA-256 hash, type or paste text into the KaviForge SHA-256 Hash Generator — the 64-character hash appears instantly. Switch to "Hash a file" for a file checksum. To create an HMAC-SHA256 signature, enable "HMAC with secret key" and enter your key.
SHA-256 is part of the SHA-2 family and produces a 256-bit hash shown as 64 hexadecimal characters. It is the standard choice for file integrity, digital signatures, blockchain, and API request signing.
HMAC-SHA256 combines SHA-256 with a secret key. It is how Stripe, GitHub, Shopify, Slack, and AWS sign webhooks and API requests, so being able to generate one quickly is useful for debugging integrations.
How to Generate a SHA-256 Hash
- 1Type or paste text, or choose "Hash a file" to select a file.
- 2Copy the 64-character SHA-256 hash.
- 3For HMAC, enable "HMAC with secret key" and enter the key.
- 4Toggle "Uppercase hex" if required.
- 5Paste an expected value into "Verify a checksum" to confirm a match.
Features
Text to SHA-256
Live SHA-256 hashing of UTF-8 text.
File SHA-256 Checksum
Verify ISO images, installers, and backups locally.
HMAC-SHA256
Create keyed signatures for webhooks and APIs.
Checksum Verification
Instantly compare against a published SHA-256 value.
Native Web Crypto
Uses the browser’s built-in, audited crypto.subtle implementation.
Private
Your text, files, and keys never leave your device.
When to Use the SHA-256 Hash Generator
Verify software downloads
Linux ISOs, Node.js, and most installers publish SHA-256 checksums.
Debug webhook signatures
Reproduce the HMAC-SHA256 a provider sends to find signature mismatches.
Content integrity (SRI)
Check that files have not changed before deploying or distributing them.
Generate deterministic IDs
Hash content to create stable, collision-resistant identifiers.
About the SHA-256 Hash Generator
Hashes are computed with crypto.subtle.digest("SHA-256") and HMACs with crypto.subtle.sign("HMAC"). Text is UTF-8 encoded, matching sha256sum, OpenSSL, Python hashlib, and Node.js crypto.
SHA-256 is secure for integrity and signatures. For password storage, use a slow, salted algorithm such as bcrypt or Argon2 instead of a single SHA-256.
SHA-256 Hash Generator FAQs
How do I generate a SHA-256 hash of a string?
Paste the string into the KaviForge SHA-256 Hash Generator. The 64-character hash is shown instantly.
How do I verify a file’s SHA-256 checksum?
Choose "Hash a file", select the file, then paste the published checksum into "Verify a checksum".
How do I create an HMAC-SHA256 signature?
Enable "HMAC with secret key", enter your key, and type the message. The HMAC-SHA256 value appears in hex.
How long is a SHA-256 hash?
256 bits, displayed as 64 hexadecimal characters.
Is SHA-256 secure?
Yes. No practical collision or preimage attacks are known against SHA-256.
Why does my webhook signature not match?
Make sure you hash the raw request body exactly as received (no reformatting), use the correct secret, and compare using the same encoding (hex vs Base64).
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