About SyntaxMaster

A fast, free toolbox built for developers.

SyntaxMaster is a collection of developer tools that run entirely in your browser. Paste JSON, YAML, SQL, or code — format it, convert it, diff it, or validate it — in milliseconds, with no sign-up and no data leaving your device.

How it works

Private by design

Every tool processes data locally. Your API responses, config files, and code never reach our servers unless you explicitly save a snippet to share.

No friction

No account required. No rate limits. No loading spinners. Paste and go — formatting runs in under 10ms.

Free forever

SyntaxMaster is free to use. It is supported by non-intrusive Google AdSense ads. Blocking ads is fine — no paywalls will ever appear.

What's included

JSONFormatter, Validator, Minifier, Diff, and converters to YAML, XML, CSV, TypeScript, Go, Python, Java, Kotlin, Rust, PHP, and Swift

FormattersYAML, TOML, XML, HTML, CSS, SQL — with dialect options and configurable indentation

Diff toolsText, JSON (semantic), YAML, XML, HTML, CSS, JavaScript, Python, Java, Go, SQL, C++, C#, and Shell

Encoders & hashesBase64 (UTF-8, Latin-1, Windows-1252), URL encoder, HTML entities, MD5, SHA-1, SHA-256, SHA-512, HMAC

UtilitiesJWT decoder/encoder (all 9 algorithms), UUID generator (v1/v4/v5/v7), Unix timestamp converter, Regex tester, Password generator, Colour converter, Number base converter, Cron explainer

Our mission

SyntaxMaster exists to give developers fast, private, and free tools that work without friction. Every tool processes your code locally in your browser — nothing is sent to any server unless you choose to save or share a snippet. No paywalls. No install. Works instantly.

Get in touch

Found a bug? Missing a tool? Have feedback?

✉ hello@syntaxmaster.dev