The Developer Toolkit
you'll actually use
Fast, free, client-side tools for everyday dev tasks. No signup, no tracking, no nonsense.
JSON Formatter & Validator
Format, prettify, minify and validate JSON data instantly with syntax error detection.
Base64 Encode / Decode
Encode text or files to Base64 format and decode Base64 strings back to readable text.
URL Encoder / Decoder
Encode special characters in URLs and decode percent-encoded URLs to human-readable form.
Password Generator
Generate cryptographically secure passwords with custom length and character options.
Word Counter
Count words, characters, sentences and estimate reading time. Get detailed text statistics.
Text Case Converter
Convert text to UPPER, lower, Title, camelCase, snake_case, kebab-case and more formats.
UUID Generator
Generate RFC 4122-compliant UUIDs (v4) in bulk. Supports uppercase and no-hyphen formats.
Lorem Ipsum Generator
Generate placeholder lorem ipsum text by paragraphs, sentences or words. HTML output supported.
HTML Minifier
Minify HTML by removing whitespace, comments and newlines to reduce file size.
Text Diff Checker
Compare two texts side-by-side and highlight added, removed and changed lines.
WhatsApp Formatter
Format WhatsApp messages with bold, italic, strikethrough and monospace. Copy and paste directly into WhatsApp.
GST Invoice Generator
Generate professional GST invoices with auto-calculated CGST, SGST and IGST. Download as PDF instantly.
Free Online Developer Tools — No Signup Required
DevToolKit is a curated collection of free online developer tools designed to speed up your daily workflow. Whether you're a frontend developer, backend engineer, or full-stack professional, our tools handle common tasks instantly in your browser — no installation, no registration, and no server-side processing of your data.
Why Use DevToolKit?
Unlike many online tools that send your data to remote servers, DevToolKit runs 100% in your browser. Your JSON, passwords, encoded strings, and text never leave your device. This makes it both fast and private — critical when working with sensitive data.
Featured Tools
Our JSON Formatter & Validator lets you instantly prettify, minify, and validate JSON — with clear error messages when your JSON is malformed. The Base64 Encoder/Decoder handles both text and file encoding. Our Password Generator uses the Web Crypto API to generate truly random, cryptographically secure passwords.
Built for Speed
All tools load instantly with no framework overhead — just clean HTML, CSS, and vanilla JavaScript. The entire toolkit is lightweight and works even on slow connections. Dark mode is supported for late-night coding sessions.