Developer tools

Local browser developer tools

Small, fast utilities from the team behind winTerm, the open-source Windows terminal. Each tool runs entirely in your browser: format and validate JSON, convert Unix timestamps between time zones, and decode JWT tokens without your data ever leaving the page.

All processing happens locally in your browser. Your input is never uploaded.

JSON Formatter & ValidatorPretty-print, minify, validate, and sort JSON without your data leaving the browser.Unix Timestamp & Time Zone ConverterTurn Unix seconds, milliseconds, and ISO 8601 dates into any IANA time zone.JWT DecoderInspect JWT headers, payloads, and time claims without sending the token anywhere.

Why local processing matters

JSON documents, timestamps, and JWT tokens often contain data you should not paste into a random website: identifiers, internal hostnames, session claims, or customer records. Many online tools quietly send that input to a server to process it. These pages work differently: the conversion logic is delivered as static JavaScript and runs inside your browser tab. Nothing you type here is uploaded, logged, or stored by winterm.dev, and the pages keep working after the first load even on a flaky connection.

The claim covers this website's own behavior. Your browser, extensions, and operating system remain under your control, as with any page. Read the full privacy policy or inspect the winTerm source on GitHub.