I've been a developer for a while now, and one thing has always annoyed me: every time I need to format some JSON, decode a JWT, or generate a password, I end up on a different site. Each one has cookie banners, newsletter popups, ads covering half the screen, and some even want me to create an account just to Base64-encode a string.
So I built ToolBox — a free collection of 130+ browser-based tools for developers and designers. No signup. No tracking. No ads. Everything runs client-side.
🧰 What's in it?
Developer Tools: JSON Formatter, Base64 Encoder/Decoder, JWT Decoder, Regex Tester, Diff Checker, SQL Formatter, Code Formatter (Prettier-powered), Hash Generator, AES Encryption, HTTP Request Builder, and more.
Design Tools: CSS Flexbox/Grid Generators, Box Shadow Builder, Gradient Generator, Color Contrast Checker, CSS Animation Builder, Font Pairing, Glassmorphism & Neumorphism generators.
Converters: JSON to YAML, XML to JSON, CSV to JSON, Markdown to HTML, Color Converter, Unit Converter, Currency Converter, Image Format Converter.
Generators: Password Generator, QR Code, Color Palette, Placeholder Images, Favicon Generator, Meta Tag Generator, Privacy Policy Generator, Dummy Data Generator.
Web & SEO: DNS Lookup, SSL Certificate Checker, Website Speed Test, Broken Link Checker, Open Graph Preview, SEO Analyzer, Redirect Chain Checker.
Image Tools: Image Compressor, Image Cropper, EXIF Data Viewer, PDF Merge & Split, SVG to PNG.
Plus: Cheat sheets for Git, Regex, HTML, CSS, and JavaScript.
⚡ What makes it different?
There are plenty of online tool sites. Here's why I built another one:
100% Client-Side: Your data never leaves your browser. When you paste a JWT token or format sensitive JSON, it's processed locally. Nothing hits a server. (Verify it in the Network tab!).
No Accounts: I don't want your email. You open the tool, use it, and leave.
Works Offline: It's a PWA with a service worker. Once you've visited a tool, it works without internet.
Cmd+K Everything: A command palette lets you search across all 131 tools instantly.
Smart Paste: Paste a JWT anywhere on the site, and it suggests opening the JWT Decoder. Paste JSON, it suggests the JSON Formatter. It auto-detects the content type.
Tool Chainer: Pipe the output of one tool into another. Base64 decode → JSON format → copy. Without opening three tabs.
🛠 The Tech Stack
Next.js (App Router, static generation)
React 19 + TypeScript
Tailwind CSS v4 with dark mode
Umami for privacy-friendly analytics (no cookies)
Sentry for error tracking
Libraries: Prettier, Leaflet (Maps), pdf-lib, and more.
Every page is statically generated at build time. No server-side rendering, no database, no backend. The site scores 100/100 on Lighthouse.
✨ Some features I'm proud of
Split View (Ctrl+Shift+S): Open two tools side by side. Handy when you're converting between formats.
Workspace Scratchpad (Ctrl+.): A multi-tab notepad that slides in from the right to stash text while working.
Snippets Manager (Ctrl+Shift+.): Save frequently used code snippets with syntax highlighting.
Input History: Every tool remembers your last 10 inputs. Click the clock icon to restore any of them.
GitHub Gist Integration: Save any tool output directly to a GitHub Gist.
📊 The Numbers
131 tools across 8 categories
18+ blog posts & 5+ cheat sheets
0 cookies
0 ads
$0 to use
🔗 Try it
Site: Toolbox
If you have tool suggestions, there's a request page on the site, I'd love to hear what tools you use most and what's missing!
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