About This Tool
Documentation
What does this tool do?
A cryptographic HMAC signing utility. Input message payloads and secret keys to generate verified message authentication codes using SHA-256, SHA-512, SHA-384, SHA-224, SHA-1, or MD5 algorithms with output formatting in Hex (lowercase/uppercase), Base64, and Base64URL.
When should you use it?
Use this tool when verifying webhook signatures from payment providers (Stripe, GitHub, Shopify, PayPal), generating API request authentication headers (AWS Signature Version 4), or testing cryptographic message integrity.
Key Capabilities & Features
Highlights
Generate Hash-based Message Authentication Codes (HMAC) across SHA-256, SHA-512, SHA-1, and MD5
Custom secret key input supporting UTF-8 plain text and raw Hex encoded keys
Output encoding options in Hexadecimal (lowercase/uppercase), Base64, and Base64URL
API webhook signature verification testing for AWS, GitHub, Stripe, and Twilio payloads
Client-side cryptographic execution utilizing Web Crypto API for zero-leak security