About DevToolBox

DevToolBox is a collection of free developer utilities designed to be fast, private, and useful — without accounts, installs, or sending your data to a server.

Why we built this

Developers constantly need small helpers: format JSON, decode a JWT, check a cron expression, convert Base64, generate a UUID. Most options either require signing up, run server-side (so your data leaves your machine), or bury the tool under ads and upsells.

DevToolBox focuses on instant, client-side tools. When a tool can run in the browser, it does. Your JSON, tokens, passwords, and source stay on your device.

What makes us different

• 100% client-side when possible — formatting, encoding, hashing, and generators use browser APIs. No upload for those tools.
• No account required — open a tool and use it. No email, no freemium wall for basic features.
• Privacy by design — we don’t store the content you paste into tools. See our Privacy Policy for details on network tools (WHOIS, domain checks) that must call public APIs.
• Practical coverage — JSON, web, crypto, AI helpers, networking, and everyday converters in one place.

How the tools work

Most pages are static HTML, CSS, and JavaScript. Calculations and transforms run in your browser (for example Web Crypto for hashes, JSON.parse for validation, canvas for image conversion). A small set of network tools (WHOIS, ARIN, domain availability) query public RDAP endpoints from your browser so you get live registration data without us storing it.

Who it’s for

Software engineers, SREs, security reviewers, students, and anyone who works with APIs, configs, or web data. If you’ve ever opened a random “JSON beautifier” and wondered where the payload went — this site is for you.

Feedback & requests

We improve tools based on real workflows. Feature ideas, bug reports, and corrections are welcome on the Contact page.

DevToolBox · devtoolbox.ai