By Developers for Developers

Engineering utilities,
reimagined.

Your data never leaves the browser. A privacy-first collection of essential tools for the modern developer workflow.

JSON Formatter

Format, beautify and validate JSON instantly. Real-time syntax validation with detailed error messages.

Open Editor →

{ "status": "pretty", "indent": 2 }

JWT Decoder

Instant decode and claim verification.

Base64

Fast encode and decode strings.

URL Encoder

RFC 3986 compliant encoding.

Hash Generator

MD5, SHA-1, SHA-256, SHA-512 & more.

Cron Builder

Human-readable cron expressions for any schedule.

Diff Checker

Compare two texts and highlight differences.

UUID Generator

Bulk generate secure UUIDs.

JSON Repair

Fix broken and malformed JSON instantly.

Password Generator

Cryptographically secure random passwords.

Password Checker

Check strength and estimated crack time.

Color Converter

HEX, RGB and HSL with CSS output.

Image to Base64

Data URL, HTML, CSS and Markdown output.

Unix Timestamp

Epoch to date, date to epoch, all formats.

SQL Formatter

MySQL, PostgreSQL, SQLite, T-SQL & more.

HTTP Status Codes

Searchable reference with REST API context.

YAML Validator

Lint YAML with line/column error location.

Case Converter

camelCase, snake_case, kebab-case and more.

Chmod Calculator

Visual Linux file permission calculator.

Base Converter

Binary, octal, decimal, hex — all at once.

XML Formatter

Beautify, validate and minify XML instantly.

Frequently asked questions

Is my data safe? Do you store anything I paste or upload?: No. Every tool on DevEssentials runs entirely in your browser using JavaScript. Nothing you type, paste, or upload is ever sent to a server. There is no backend — your data never leaves your device.
Do I need to create an account or sign up?: No account, no email, no signup. All tools are free and open to use immediately.
Do the tools work offline?: Yes. Once the page has loaded, all tools work without an internet connection. There are no API calls to external services.
Are these tools free to use commercially?: Yes. You can use DevEssentials for personal or commercial work without restrictions.