HMAC-SHA256 Generator
Create an HMAC-SHA256 signature from a message and a secret key. Used for webhooks, API request signing and JWTs.
Part of the free Hash Generator. Runs in your browser — nothing is uploaded.
HMAC-SHA256 Generator
HMAC-SHA256 mixes a secret key with the message before hashing. Anyone who knows the key can verify the digest; nobody else can forge it. Paste a message and a key to see the hex signature.
Worked example: A webhook-style signature
Message + key
message: hello key: secret
HMAC-SHA256
88aab3ede8d3adf94d26ab90d3bafd4a2083070c3bcce9c014ee04a443847c0b
Practical tip
Hash the raw request body, not a pretty-printed copy. A single extra space changes the HMAC and verification fails.
How to use this Hash Generator
- 1Use the live tool above — it runs entirely in your browser and never uploads your data.
- 2Paste the sample from the worked example, or use your own input.
- 3Copy the result, then adapt the same steps in your editor, script, or pipeline.
HMAC-SHA256 Generator FAQs
Is HMAC the same as a hash?
No. A hash has no key. HMAC needs a secret, so only parties that share the key can produce the same digest.
Hex or Base64?
Both are common. GitHub webhooks use hex. Some JWT and AWS signatures use Base64. Match the spec you are implementing.
More Hash Generator pages
- SHA-1 Hash GeneratorGenerate a SHA-1 hash of any text or file. 40-character hex digest, computed in your browser. Free and private.
- SHA-512 Hash GeneratorGenerate a SHA-512 hash online. 128-character hex digest of text or files, computed locally in your browser.
- File Checksum CalculatorCalculate MD5, SHA-1, SHA-256, SHA-384 and SHA-512 checksums of a local file. The file never leaves your browser.
- Verify a File ChecksumCheck whether a file matches a published MD5, SHA-1 or SHA-256 checksum. Paste the expected hash and compare locally.
- SHA-384 Hash GeneratorGenerate a SHA-384 hash of text or a file. 96-character hex digest, computed in your browser.
- Generate a Hash From a StringHash any string with MD5, SHA-1, SHA-256, SHA-384 and SHA-512 at the same time. Instant, private, in-browser.
- Compare Two Hash ValuesCompare two hex hashes and see if they match. Useful when a vendor checksum and your local digest disagree.
- Hash Text Online FreeFree online text hasher. MD5, SHA-1, SHA-256, SHA-384 and SHA-512 as you type. No signup, nothing uploaded.
- Checksum Generator for DownloadsGenerate a SHA-256 or MD5 checksum to publish next to a download. Hash the release file locally and copy the digest.