← Home
中文

HMAC Calculator

HMAC-SHA1, SHA-256, SHA-384, SHA-512

—

About HMAC

  • HMAC (Hash-based Message Authentication Code) is defined by RFC 2104, used to verify both data integrity and authenticity
  • Unlike a plain hash, HMAC requires a shared secret key — without the key, an attacker cannot forge a valid signature
  • The output length matches the underlying hash: SHA-1 = 20 bytes, SHA-256 = 32 bytes, SHA-384 = 48, SHA-512 = 64

Common use cases

  • API request signing — AWS Signature V4, Alibaba Cloud, Stripe webhooks
  • Webhook verification — GitHub, Stripe, Slack send HMAC headers to prove the webhook is genuine
  • Session tokens — JWT HS256 is essentially HMAC-SHA256 signing
  • TOTP — Google Authenticator uses HMAC-SHA1 internally

User Reviews

Average 4.8 stars based on 6 user reviews.

Frank Xu2026-03-13
Role: SRE

The page focus is clear: the core is hmac calculator, hmac sha256, and credential format review. HMAC Calculator can locally validate credentials, hashes, or key formats; local processing is better for sensitive text, which makes it easy to judge before using it.

Lisa Li2026-06-18
Role: Security Engineer

When I need hmac calculator for hmac sha256, I care about fewer steps. HMAC Calculator keeps hex/base64 output direct; with API signature generation, follow-up review is easier for visitors coming from search.

Jennifer Chen2026-03-23
Role: Backend Engineer

I found HMAC Calculator while looking for free online hmac calculator, and the real issue was that credentials, hashes, and key formats are risky to handle manually. API signature generation and browser-based are on the same page, so I can enter security parameters and generate reviewable output without stitching several tools together.

Michelle Zhao2026-06-02
Role: DevOps Engineer

For hmac calculator work, the important part is whether the output is easy to verify. HMAC Calculator puts browser-based up front, the result is ready for testing or configuration, and it handles hmac sha256 work without sending me to another page.

Linda Zhou2026-03-07
Role: System Administrator

Our team runs into this during credential format review: security debugging needs quick reviewable output. HMAC Calculator keeps the hmac calculator flow short, and straightforward option setup helps with pre-handoff review for repeated System Administrator work.

Emily Lin2026-06-12
Role: Tech Lead

I needed hmac calculator that could enter security parameters and generate reviewable output, not just a generic page. HMAC Calculator keeps straightforward option setup and free online HMAC (Hash-based Message Authentication Code) calculator close to the real workflow, and it reduces manual mistakes with keys, digests, or rules.