Every developer has a bookmarks folder full of random utilities — JSON formatters, Base64 decoders, UUID generators, password tools.
Most of them are drowning in ads, ask you to sign up, or hide basic features behind a paywall.
So I decided to build my own. All 11 of them. Every single one is free, runs client-side in your browser, and requires zero signup.
The Full Suite
🔧 Dev Utilities
jsonformat.co — JSON Formatter
Paste ugly JSON → get beautiful JSON. Syntax highlighting, error detection, tree view.
createuuid.com — UUID Generator
UUID v1, v4, v7 generation. Bulk mode — copy one or a thousand.
makelorem.com — Lorem Ipsum Generator
Customizable: paragraphs, sentences, or word count.
🔤 Encoding & Conversion
base64decode.co — Base64 Encode/Decode
Handles text, files, URLs. The one you'll bookmark.
hextoascii.co — Hex ↔ ASCII Converter
Debug binary data without the headache.
🔐 Security
password-generator.co — Password Generator
Cryptographically secure passwords using crypto.getRandomValues(). Your passwords never touch a server.
hashgenerator.co — Hash Generator
SHA-256, MD5, SHA-512 and more. Hash anything right in your browser.
🧪 Testing Data
namso.io — Test Credit Card Numbers
Valid Luhn algorithm numbers for dev/QA testing. Multiple networks supported.
randomimei.com — Random IMEI Generator
IMEI numbers for device testing. Valid check digits.
randomiban.co — Random IBAN Generator
Test IBAN numbers for payment integration testing. 30+ countries.
randommac.com — Random MAC Address Generator
MAC addresses for network testing. All major vendor prefixes.
Why I Built These
I kept running into the same pattern: need a quick dev utility → Google it → land on a site that's 70% ads, wants my email, or limits usage unless I pay.
These tools should be free. They're simple browser-based utilities. There's no reason they need accounts, tracking, or premium tiers.
So I built them with a few principles:
- 100% client-side — Nothing gets sent to any server. You can verify in DevTools.
- Zero signup — No accounts, no emails, no "free trial."
- Clean UI — Minimal design, fast loading, no popups.
- Mobile friendly — Works on any device.
Tech Stack
All 11 sites are static sites with client-side JavaScript. No backend processing for the core functionality. They're fast, lightweight, and work offline after first load.
What's Next?
I'm actively working on improvements based on feedback. A few things on the roadmap:
- Passphrase generation (diceware-style) for the password generator
- More hash algorithms
- Batch processing modes
- API endpoints for CLI users
What free dev tools do you keep bookmarked? Always looking for ideas on what to build next.
All tools are free and will stay free. If you find them useful, a bookmark or share helps more than you'd think. 🙏
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