Developer
Encoders, converters & dev utilities
Developer calculators
12 tools for Base64, Cron parser, Color convert and more — accurate, instant, and free.
Reckonist’s Developer tools are free encoders, converters and utilities — JWT decoding, UUID generation, Base64 and URL encoding, and more — that run entirely in your browser, with nothing uploaded to a server. They’re fast, need no sign-up, and your input never leaves your device.
Encoders & converters6
Data-Format Converter (JSON ↔ CSV / YAML / XML)
Convert JSON ↔ CSV, YAML & XML (+ JSON→TypeScript) in your browser.
Base64 Converter
Encode & decode Base64 — text, hex, PDF & images, URL-safe. In your browser.
Epoch / Unix Timestamp Converter
Convert Unix timestamps ↔ dates — seconds/ms auto-detect, timezones & code snippets.
Color Converter (HEX ↔ RGB ↔ HSL)
Convert colors between HEX, RGB & HSL with a live swatch. In your browser.
Number-Base Converter
Convert between binary, octal, decimal, hex & any base 2–36 — with steps & two's complement.
Text to Binary Converter
Convert text ↔ binary, ASCII & hex (UTF-8 aware) — with step-by-step working.
Generators & security3
JWT Decoder & Verifier
Decode & verify JWTs in your browser — header, payload, expiry, signature.
UUID Generator
Generate UUID v4, v7 & nil — single or bulk, with format options.
Hash Generator
MD5, SHA-1/256/512, CRC32 & HMAC — hash text or files in your browser.
Reference3
Cron Expression Generator & Explainer
Build & explain cron expressions — plain English, next run times & multiple schedulers.
HTTP Status Codes Reference
Every HTTP status code (1xx–5xx) — meaning, when to use & how to handle.
Regex Cheat Sheet & Common Patterns
Regex syntax reference + copy-ready email/date/URL patterns, per-language notes & a live tester.