HMAC Generator
Hash a message with a secret key using HMAC to verify authenticity and integrity. Supports MD5, SHA-1, SHA-256 and SHA-512 variants, plus optional hex/Base64 output. Runs entirely on your device.
Runs 100% in your browserNo signup neededFree forever
Enter a message and a secret key, then pick an algorithm and output encoding. The HMAC uses the key to keyed-hash the message — the same construction as most API signatures.
Inputs
Algorithm
HMAC-SHA256 (hex)
e31f46f839354f0175e2eb93d944f839819ece337d6884efd04596acfc4649f2Frequently asked questions
What is HMAC used for?
HMAC verifies both the integrity and the authenticity of a message when both parties share a secret key — e.g. webhook signatures and API authentication.
Is HMAC different from a normal hash?
Yes — HMAC mixes a secret key into the hashing process, so the same message produces a different HMAC with a different key.
More tools
JSON Formatter & ValidatorBeautify, minify, validate and explore JSON with a tree view.Base64 Encoder / DecoderEncode and decode Base64 text with full UTF-8 support.Hash GeneratorGenerate MD5, SHA-1, SHA-256 and SHA-512 hashes instantly.Text Diff CheckerCompare two texts side by side with live highlighting.Regex TesterLive pattern matching with highlighted matches and groups.UUID GeneratorBulk generate RFC 4122 UUIDs (v4 & v7) in one click.URL Encoder / DecoderEncode and decode URLs and query parameters cleanly.CSV ⇄ JSONConvert CSV tables to JSON and back, with live preview.JWT DecoderDecode JWTs into header, payload and signature views.Timestamp ConverterConvert Unix timestamps, ISO dates and human dates both ways.Hex ViewerInspect text bytes as an offset, hex, ASCII classic hexdump.Case ConverterConvert text between camelCase, snake_case, kebab-case and more.URL Slug GeneratorTurn any title or phrase into a clean, SEO-friendly URL slug.Lorem Ipsum GeneratorGenerate placeholder text: words, sentences or paragraphs.Password GeneratorGenerate strong random passwords with an entropy estimate.Text StatisticsCount words, characters, lines, sentences and reading time.HTML Entities Encoder / DecoderEncode or decode HTML entities (&, <, &) safely.Color Converter & Contrast CheckerConvert HEX, RGB, HSL and HSV with WCAG contrast ratios.CSS Unit ConverterConvert px ⇄ rem ⇄ em with a configurable root font size.HTML FormatterBeautify messy HTML with clear indentation and tags.CSS MinifierMinify CSS: strip comments, whitespace and shorten colors.YAML ⇄ JSONConvert between YAML and JSON with strict validation.SQL FormatterBeautify SQL with configurable indentation and keywords.CSV → SQL GeneratorTurn CSV data into CREATE TABLE and INSERT statements.Cron Expression ParserExplain cron schedules like '*/5 * * * *' in plain English.IPv4 Subnet CalculatorCalculate networks, broadcast addresses and host counts for CIDR.