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Dev Doctor — Free Online Developer Tools
Dev Doctor is a free suite of 40+ browser-based developer utilities for
formatting, encoding, inspecting and converting data. Everything runs
locally in your browser — no sign-up, no installation, and your input never
leaves your device. The full list of tools available on the web:
Text & Data
JSON Formatter — Format and validate JSON.
JSON Editor — Visually edit JSON tree nodes.
Regex Tester — Test patterns with live match highlighting.
Hash Generator — Generate MD5, SHA-1, SHA-256 and more.
Diff Viewer — Compare two text blocks side by side.
Base64 / URL Encoder — Encode and decode Base64 and URLs.
Markdown Viewer — Render and preview Markdown.
JWT Tool — Decode tokens and sign new JWTs.
Number Base Converter — Convert between DEC, HEX, BIN and OCT.
URL Parser / Builder — Inspect and construct URLs.
String Case Converter — Convert between camelCase, snake_case and more.
HTML Entity Encoder — Encode and decode HTML entities.
Cron Parser — Parse cron expressions and preview upcoming runs.
Date Format Playground — Try date format patterns interactively.
XML Formatter — Format and pretty-print XML documents.
JSON to Kotlin — Generate Kotlin data classes from JSON.
Text Inspector — Character, word and line stats plus byte sizes.
Network
HTTP Request Tester — Send HTTP requests and inspect responses.
Asset DPI Preview — Preview asset rendering across Android densities.
Spacing Grid Overlay — Overlay an 8dp Material grid on any screenshot.
Android Developer Tools
These tools rely on Android platform features and run in the Dev Doctor
Android app: dp / px Calculator, Permission Inspector, Deep Link Launcher,
Device Info, ADB Wi-Fi Helper, Traffic Monitor, Logcat Filter, App Inspector,
Crash Log Formatter, Intent Fuzzer and Mock Server.