DevKit: JSON, JWT & Dev Tools

30+ developer tools in one app — JSON, Base64, JWT, hashes & more. 100% offline, privacy-first. No data ever leaves your device.

DevKit puts 30 developer utilities in your pocket — and every one runs entirely on your device.

Stop juggling browser tabs. Stop pasting production tokens into random websites. Format JSON, decode a JWT, test a regex, or convert a timestamp on a train, on a plane, or inside a locked-down corporate network.

YOUR WORK STAYS ON YOUR DEVICE

Every tool runs locally. The JSON you paste, the token you decode, the certificate you inspect — none of it is uploaded to a server, and none of it is visible to us. All 30 tools work with no internet connection. No account, no sign-up, no email required.

FORMATTERS

JSON Formatter: Beautify or minify JSON with error highlighting and tree view HTML Formatter: Beautify, minify, and preview HTML with live rendering CSS Formatter: Format and validate CSS with syntax highlighting JS Formatter: Format and minify JavaScript XML Formatter: Format and validate XML documents SQL Formatter: Format and validate SQL queries

PARSERS & DEBUGGERS

JWT Debugger: Decode tokens, inspect headers and payloads, verify signatures Cron Parser: Parse cron expressions with next run calculations Certificate Decoder: Decode X.509 certificates

ENCODERS & DECODERS

Base64: Encode and decode Base64 strings URL Encoder: Encode, decode, and parse URLs HTML Encoder: Handle HTML entities Hash Generator: Generate MD5, SHA-1, SHA-256, SHA-512 hashes Backslash Escape: Escape and unescape special characters

CONVERTERS

Timestamp: Convert Unix epoch timestamps to readable dates Case Converter: Transform between camelCase, snake_case, UPPER CASE, and more Color Converter: Convert between HEX, RGB, HSL with live preview YAML to JSON: Convert between YAML and JSON with tree view Number Base: Convert between Binary, Octal, Decimal, Hexadecimal Hex to Text: Convert between hex and ASCII CSV to JSON: Convert between CSV and JSON

GENERATORS

UUID/ULID Generator: Create UUIDs and ULIDs instantly QR Code: Generate customizable QR codes and export as images Lorem Ipsum: Generate placeholder text Random String: Generate secure passwords and API keys

TEXT & COMPARISON

Diff Checker: Compare text with highlighted differences RegEx Tester: Test regex with live match highlighting Markdown Previewer: Preview Markdown with GitHub Flavored support Line Sort: Sort and deduplicate lines String Inspector: Analyze string statistics

BUILT FOR MOBILE

Smart History: Auto-saves recent work, stored only on your device Instant Paste: Smart clipboard detection Quick Actions: One-tap copy, clear, share Native Performance: Blazing fast, no loading screens Light & Dark Modes: Beautiful design for any environment

WHO IT'S FOR

Software engineers debugging away from a desk Site reliability engineers checking cron schedules and certificates during an incident Backend developers inspecting tokens and payloads Engineering managers reviewing a diff or a config between meetings Anyone who needs dev tools without a network

PRICING Pro: $9.99/month or $39.99/year (save 67%) 3-day free trial. Cancel anytime.

WHY DEVKIT

Works with no connection Your work never leaves the device Fast, native performance Regular updates with new tools No ads, ever Built by a developer, for developers

Download DevKit and take your tools anywhere.

Terms of Use: Apple's Standard EULA (https://www.apple.com/legal/internet-services/itunes/dev/stdeula/)