Developer Tools

Free, client-side developer utilities. No signup, no data sent anywhere.

Validate your .env files

Check for syntax errors, deprecated variables, and production readiness.

Share a secret securely

One-time, end-to-end encrypted links for passwords, API keys, or full .env files. Atomic burn-on-read with a passphrase as a second factor.

Open send.env.dev →

Formatters

JSON Formatter & Validator

Format, prettify, validate, and minify JSON online. Syntax highlighting, configurable indent, and clear errors on invalid JSON — runs entirely in your browser.

SQL Formatter

Format and beautify SQL for MySQL, PostgreSQL, SQLite, and SQL Server. Uppercase keywords, indent clauses, and make CTEs and stored procedures readable.

Markdown Preview

Preview Markdown as HTML in real time. Headings, lists, bold, italic, inline code, and blockquotes render instantly — perfect for docs and README writing.

CSS Minifier / Beautifier

Minify and beautify CSS online. Strip whitespace and comments to shrink stylesheet size, or reformat compressed CSS for readability — runs entirely in your browser.

Encoders & Decoders

Base64 Encode / Decode

Encode and decode Base64 and Base64URL strings online. Toggle between standard Base64 and URL-safe Base64URL with real-time conversion.

URL Encode / Decode

Encode and decode URLs with full percent-encoding support. Safely escape query strings, path segments, and form-data payloads for web APIs and HTTP requests.

JWT Debugger

Decode, inspect and verify JSON Web Tokens. View claims with OIDC descriptions, verify signatures with HS256/RS256/ES256, and auto-fetch public keys from OIDC issuers.

HTML Entity Encode / Decode

Encode and decode HTML entities online. Escape <, >, &, quotes, and Unicode for safe rendering inside HTML, JSX, and email templates — runs entirely in your browser.

Image to Base64 Converter

Convert images to Base64 data URIs online. Drag and drop or upload any image to get Base64 encoded output.

Generators

UUID Generator

Generate v4 UUIDs online — bulk generation up to 1000 at once, instant copy to clipboard, RFC 4122 compliant. Uses crypto.randomUUID, runs in your browser.

Hash Generator

Generate SHA-1, SHA-256, and SHA-512 hashes from any text or string. Browser-based cryptographic hashing for checksums and fingerprinting — nothing is uploaded.

Lorem Ipsum Generator

Generate lorem ipsum placeholder text instantly. Pick paragraphs, sentences, or words — perfect for mocking layouts, design comps, and CMS content templates.

Password Generator

Generate strong, random passwords and passphrases online. Strength meter, configurable character sets, and word-based passphrase mode.

QR Code Generator

Generate QR codes from any text, URL, or vCard online. Adjustable size up to 512px, error-correction levels, instant PNG download, and live preview — no tracking.

.gitignore Generator

Generate safe, thorough .gitignore files. Every output includes a safety baseline (OS droppings, editor swap files, logs, secrets) and covers 50+ languages, frameworks, tools, editors, and platforms.

Dockerfile Generator

Generate production-ready Dockerfiles for Node.js, Python, Go, Rust, Java, and more. Multi-stage builds, slim base images, and non-root user defaults built in.

JWT Generator

Create and sign JSON Web Tokens with custom claims online. Supports HS256, HS384, and HS512 algorithms.

Meta Tag Generator (OpenGraph, Twitter Cards, SEO)

Generate OpenGraph, Twitter Card, and basic SEO meta tags. Enter your title, description, URL, and image — copy the HTML snippet. Optional JSON-LD. Runs entirely in your browser.

.env Builder

Generate ready-to-use .env files for Node.js, Docker, and AWS. Pick a template and an environment (development, staging, production), copy or download.

Converters

Unix Timestamp Converter

Convert Unix timestamps to human-readable dates and back. Handles seconds, milliseconds, UTC, local time zones, ISO 8601, and relative times — fast and offline.

Color Converter

Convert colors between HEX, RGB, HSL, HSV, and OKLCH online. Live preview, named CSS colors, WCAG contrast check, and instant copy in any format — no signup.

Number Base Converter

Convert numbers between decimal, hexadecimal, octal, and binary instantly in your browser. Handy for debugging bitmasks, color hex codes, and chmod permissions.

Text Case Converter

Convert text between camelCase, PascalCase, snake_case, kebab-case, UPPER, lower, Title and Sentence case.

YAML ↔ JSON Converter

Convert YAML to JSON and JSON to YAML in your browser. Bidirectional conversion preserves nested structure, anchors, and types — for Kubernetes manifests and CI configs.

JSON to TypeScript

Convert JSON objects into TypeScript interfaces and types. Generate accurate types from API responses or sample data instantly — runs entirely in your browser.

cURL to Code Converter

Convert cURL commands to Python, JavaScript, Go, PHP, and Ruby code. Free online cURL converter.

JSON to CSV Converter

Convert JSON arrays to CSV and CSV to JSON online. Handles nested objects with automatic flattening.

Markdown to HTML Converter

Convert Markdown to HTML with live preview. Supports GitHub-flavored Markdown — tables, task lists, code fences, autolinks — with sanitized HTML output you can copy.

HTML to Markdown Converter

Convert HTML to clean Markdown online. Handles headings, lists, links, images, code blocks, and tables.

TOML / JSON / YAML Converter

Convert between TOML, JSON, and YAML formats online. Bidirectional config file converter.

Paste a .env file, get the equivalent for Docker Compose, Kubernetes ConfigMap, Vercel CLI, AWS Parameter Store, GitHub Actions secrets, or shell exports. Client-side — your file never leaves the browser.

Testers

Regex Tester

Test and debug JavaScript regular expressions online. Live match highlighting, capture group inspection, flag support (gim), and instant syntax error feedback.

Diff Checker

Compare two text blocks side-by-side and highlight inline differences. Word- and line-level diff for code, JSON, config files, and prose — runs in your browser.

Cron Expression Parser

Parse and explain cron expressions in plain English. See upcoming run times, validate syntax, and understand schedules for crontab, Kubernetes, and CI jobs.

JSONPath Tester

Test JSONPath expressions against JSON data online. Live results with example expressions.

.env Validator

Validate your .env file for syntax errors, deprecated variables, missing production requirements, naming conventions, and live secret leaks (AWS keys, GitHub PATs, Stripe live keys, Slack tokens, Google API keys, npm tokens, PEM private keys). Client-side — your file never leaves the browser.