About DevToolWorld

DevToolWorld is a collection of free tools for everyday development work: formatting and validating JSON, YAML, SQL, HTML, Markdown and Java; decoding JWTs and Base64; generating UUIDs, Dockerfiles, Kubernetes manifests and Git commands; testing regular expressions; and more. There are 25 tools in 24 categories, each with a written guide to the format or problem behind it.

Who runs it

DevToolWorld is developed and maintained by Sarbjit Singh, who writes the tools, the articles and the guides. You can reach us at [email protected]. Every message is read, and bug reports in particular are welcome.

Why it exists

Developers paste a lot of sensitive material into online tools: access tokens, API responses with customer data, production configuration files, internal SQL. Many tools send that input to a server to process it, often without saying so. DevToolWorld was built on a simple rule: your input stays in your browser. The tools should also be fast, work without an account, and explain what they are doing, rather than just producing an answer.

How the tools work

The site is a set of static pages. When you open a tool, its code is downloaded into your browser, and from then on everything you type, paste or open is processed by JavaScript on your own device. Nothing you enter is uploaded, stored or logged by DevToolWorld. You can check this yourself: open your browser's developer tools, go to the Network tab, and use a tool. No request carries your input.

The tools are built on well-tested open-source libraries where they exist, including Prettier and its Java plugin for code formatting, sql-formatter for SQL, and js-yaml for YAML. Others use standard browser features, such as the Web Crypto API for UUIDs and HMAC signature checks, and the WHATWG URL parser for URLs.

There is one deliberate exception. The API Request Builder can send an HTTP request when you click Send. That request goes directly from your browser to the address you entered. It does not pass through DevToolWorld.

How the content is written

Each tool page has a hand-written article covering what the tool does, how to use it, common errors and their fixes, and answers to frequent questions. The examples are produced by running the real code, and each page shows the date it was last reviewed. The guides explain the underlying concepts in more depth. If you find a mistake, please tell us. Corrections are made quickly, and the review date is updated.

How the site is funded

DevToolWorld is free to use. It uses Google Analytics to understand which tools are used, and may show advertising served by Google AdSense to cover running costs. The privacy policy explains exactly what those services collect and how to opt out. The tools themselves never send your input to analytics or advertising providers.

Contact

Questions, bug reports, tool suggestions and corrections: [email protected]. See the contact page for tips on writing a useful bug report.