Why I Built DevUtil: Privacy-First Developer Tools in the Browser

I kept opening “free online tools” for the same jobs: format JSON, beautify SQL, decode a JWT, convert YAML, build a cron expression. Most of them worked. Many also sent whatever I pasted to a server.

That is a bad default for production payloads, tokens, and customer data.

So I built DevUtil.dev — a privacy-first toolbox where processing stays in the browser.

What DevUtil covers today

The suite is past “a couple of utilities.” It currently includes 22 tools, plus short guides:

• Formatters: JSON, SQL, XML
• Converters: YAML ↔ JSON, JSON ↔ CSV, case converter, number bases
• Generators / helpers: cron builder, UUID v4 & v7, password / QR / hashes
• Everyday debugging: regex tester, JWT decoder, diff checker, Markdown preview

See the full changelog on What’s New.

Why client-side tools matter

1. Secrets stay local — JWT payloads, SQL filters, and API dumps never need to leave your machine for formatting.
2. Speed — no round trip for the core action.
3. Offline-friendly — once the page loads, many tools keep working without calling an API.
4. Trust is visible — you can inspect network traffic and confirm nothing sensitive is uploaded.

Analytics on DevUtil is aggregate only (page views / button events). Tool inputs are not the product data model.

A practical workflow

A day I actually have:

1. Pretty-print an API response in the JSON Formatter
2. Convert a Kubernetes snippet with YAML ↔ JSON
3. Clean a query for review in the SQL Formatter
4. Schedule a job with the Cron Generator

If you want the “why” behind formats, the guides cover JSON formatting, SQL formatting, cron examples, and YAML vs JSON.

What I’m optimizing for next

• Stronger search pages for high-intent tools
• Better internal linking from my portfolio and writing
• More guides that answer real questions, not fluff

If you try DevUtil, start here: https://www.devutil.dev/. Feedback on missing tools is welcome.