DevKit - Developer Toolbox

Essential developer utilities in your browser toolbar. JSON, Base64, JWT, hashes, timestamps, regex, colors, diff and more.

DevKit puts essential developer utilities right in your browser toolbar. No more switching tabs to format JSON, decode a JWT, or convert a timestamp. ── FORMATTERS ── • JSON Formatter — format, minify, and validate JSON with instant error feedback • Diff Viewer — compare two blocks of text side-by-side and see exactly what changed • Markdown Preview — write Markdown and see the rendered output live ── ENCODERS & DECODERS ── • Base64 — encode or decode Base64 strings in one click • URL Encoder — encode or decode URL/URI components • JWT Decoder — inspect the header, payload, and expiry of any JWT token • HTML Entities — escape and unescape HTML entities • Hash Generator — generate MD5, SHA-1, SHA-256, and SHA-512 hashes ── CONVERTERS ── • Timestamp — convert between Unix timestamps and human-readable dates (ms and seconds) • Number Base — convert between binary, octal, decimal, and hexadecimal • Color Converter — convert between HEX, RGB, and HSL with a live color preview • Case Converter — switch text between camelCase, PascalCase, snake_case, kebab-case, and more ── GENERATORS ── • UUID Generator — generate v4 UUIDs instantly, one or in bulk ── INSPECTORS ── • Regex Tester — test patterns against live text with match highlighting and capture groups • String Inspector — count characters, words, lines, and bytes in any text ── WHY DEVKIT ── ✓ Results update as you type — no buttons to click ✓ One-click copy on every output ✓ Keyboard shortcut: Ctrl+Shift+D (Cmd+Shift+D on Mac) ✓ Dark and light themes ✓ Remembers your last tool and input between sessions ✓ Fully offline — nothing is sent anywhere ── PRIVACY ── DevKit runs entirely in your browser. No data leaves your machine. No accounts. No analytics. No tracking. Ever. ─────────────────────────────────────── DevKit covers the browser. 1DevTool covers everything else. Need AI agent terminals, an API client, and connections to 13 databases — all in one desktop app? → https://1devtool.com/