50 Free Browser Tools Every Developer Should Bookmark

David Miller — Fri, 13 Feb 2026 19:51:57 +0000

I got tired of googling "free JSON formatter" every other day, so I built FreeToolBoxes.com — a collection of 60+ free browser-based tools. No signup, no downloads, no tracking. Everything runs client-side.

Here's the breakdown by category:

🛠️ Developer Tools

These are the ones I reach for daily:

JSON Formatter — Paste messy JSON, get it pretty-printed
JSON Validator — Find exactly where your JSON is broken
Base64 Encoder/Decoder — Encode/decode strings instantly
JWT Decoder — Inspect JWT tokens without installing anything
Regex Tester — Test patterns with real-time matching
Cron Generator — Build cron expressions visually
Hash Generator — MD5, SHA-1, SHA-256 hashing
CSS Minifier — Shrink your CSS
JS Minifier — Minify JavaScript
HTML Encoder/Decoder — Escape/unescape HTML entities
CSV to JSON / JSON to CSV — Convert between formats
DNS Lookup — Check DNS records for any domain
IP Lookup — Geolocation and ISP info

🎨 Design & Color Tools

Color Picker — Pick colors, get HEX/RGB/HSL
Color Palette Generator — Generate harmonious palettes
Gradient Generator — CSS gradients with live preview
Favicon Generator — Create favicons from images or text

🖼️ Image Tools

Image Resizer — Resize without uploading anywhere
Image Compressor — Reduce file size in-browser
Image Cropper — Crop with custom dimensions
Base64 Image Encoder — Convert images to data URIs

📝 Text Tools

Word Counter — Words, characters, sentences, reading time
Case Converter — UPPER, lower, Title, camelCase, etc.
Lorem Ipsum Generator — Placeholder text on demand
Markdown Preview — Live markdown rendering
Text Diff — Compare two blocks of text
Slug Generator — URL-friendly slugs from any text

🔢 Math & Utility

Percentage Calculator — All percentage math in one place
Unit Converter — Length, weight, temperature, etc.
BMI Calculator — Quick health check
Age Calculator — Exact age from birthdate
Aspect Ratio Calculator — For responsive design math

🔐 Validators & Converters

Credit Card Validator — Luhn check for testing
IBAN Validator — Validate international bank numbers
Currency Converter — Live exchange rates
Binary/Hex/Decimal Converter — Number base conversions
ASCII Converter — Text to ASCII and back

The Stack

Deliberately simple:

Pure HTML/CSS/JS — no frameworks, no build step
Cloudflare Pages — free hosting, global CDN
Client-side only — your data never leaves your browser

Total hosting cost: $0/month

Why I Built This

Every time I needed a quick tool, I'd land on some site that wanted me to sign up, watch an ad, or "upgrade to Pro" to unlock basic features. So I built the tools I actually use and put them all in one place.

The whole thing is open and free. If there's a tool you wish existed, drop a comment — I'll probably build it this week.

👉 freetoolboxes.com

Forem: David Miller