Developer
The Developer hub collects fast browser utilities for everyday technical cleanup. Format and validate JSON, decode JWT claims, test regex patterns, prettify SQL, convert curl commands to fetch snippets, encode and decode URLs and Base64 strings, and generate QR codes for demos or documentation. Nothing replaces production security review, but these tools save minutes when you are debugging API responses, reading log excerpts, or preparing support messages. Processing stays in the browser for supported workflows — paste, transform, copy. Pair JSON Formatter with JSON Validator when you are unsure whether the issue is syntax or readability.
All tools
Developer tools
URL Encoder / Decoder
Encode or decode URL text safely for links, query strings, and web forms.
🔒 Browser only
JSON Formatter
Format, minify, and validate JSON text with friendly error messages.
🔒 Browser only
Base64 Encoder / Decoder
Encode text to Base64 or decode Base64 back into readable text.
🔒 Browser only
Regex Tester
Test regular expressions against sample text in your browser.
🔒 Browser only
JWT Decoder
Decode JWT header and payload JSON without verifying the signature.
🔒 Browser only
SQL Formatter
Format SQL queries for easier reading and debugging.
🔒 Browser only
JSON Validator
Validate JSON syntax and show friendly parser feedback.
🔒 Browser only
CURL to Fetch Converter
Convert simple cURL commands into JavaScript fetch examples.
🔒 Browser only
QR Code Generator
Generate QR codes for URLs, text, Wi-Fi passwords, email, and phone numbers. Download as PNG. No signup, no tracking.
🔒 Browser only
Password Generator
Generate strong, random passwords with custom length and character sets. Everything runs in your browser — nothing is ever sent to a server.
🔒 Browser only
Markdown to HTML Converter
Convert Markdown to clean HTML with live preview. Supports headings, bold, italic, tables, code blocks, blockquotes, and links. All in your browser.
🔒 Browser only
Featured developer guides
Productivity Guides
Best Free Online Tools for Daily Work
A useful roundup of browser-based tools for documents, images, text cleanup, passwords, calculations, and quick productivity tasks.
6 min read
Security Guides
Password Generator Guide: How to Create Strong Random Passwords
Learn what makes a password stronger, how to use a password generator, and why storage matters as much as password length.
5 min read
Productivity Guides
Browser-Based Tools vs Desktop Software: How to Choose Wisely
A practical comparison of online utilities and installed apps for PDFs, images, AI writing, and security—plus a decision framework teams and students can reuse.
14 min read
Developer Guides
QR Code Generator: How to Create QR Codes for Any Use Case
QR codes are everywhere — menus, business cards, WhatsApp groups, event posters. Here is how to create them for free for any use case in seconds.
5 min read
About developer tools
Developer utilities are small but frequent tasks. Formatting JSON, decoding URLs, creating UUIDs, or converting Base64 text should be fast, readable, and easy to copy.
These tools are designed for snippets, examples, testing, support messages, and lightweight debugging. They do not replace full validation, security review, or production testing.
When pasting production config or customer payloads, prefer scrubbing secrets first—even local tools can end up in screen shares or support tickets by accident.
Pair JSON Formatter with JSON Validator when you are unsure whether the issue is syntax or readability; pairing saves cycles compared to staring at one minified line.
freetoolkitapp is designed for fast, no-signup workflows on mobile and desktop. Browse all tools or pick a workflow above.
FAQ
Frequently asked questions
Can I format JSON online?
Yes. JSON Formatter validates, formats, and minifies JSON in the browser.
Are UUIDs secrets?
No. UUIDs are identifiers, not passwords or authentication tokens.
When should I encode a URL?
Encode URL parts when spaces or special characters need to be safely included in a link or query string.