What Staaarter Tools is
Staaarter Tools is a collection of 1783 free, browser-based developer utilities: formatters, validators, converters, and encoders for everyday tasks like checking JSON, diffing text, or converting between data formats. There is no sign-up, no account, and no paywall. Every tool is available immediately at its own URL.
Why it runs entirely in your browser
Every tool on this site processes your input using JavaScript running locally in your browser tab. There is no backend API that receives the text, files, or data you paste in, and nothing is uploaded before a result is shown. That design choice exists specifically so you can safely use these tools on data you wouldn't want to send to a third-party server: production config, API responses, internal documents, or anything else you'd rather keep on your own machine. See our Privacy Policy for the specifics of what, if anything, is stored locally.
Who maintains it
Staaarter Tools is built and maintained by Staaarter Tools Team. Source and issue tracking are public on GitHub. If you find a bug, have a tool request, or spot something inaccurate in a tool's documentation, the Contact page has the fastest way to reach us.
How accuracy is maintained
Tool behavior (parsing, validation, conversion) is implemented against the relevant published specification for each format, for example RFC 8259 for JSON, rather than reverse-engineered from a single library's behavior. Documentation content is reviewed for technical accuracy and updated when a tool's behavior changes; each tool page shows its own last-updated date in the header.