Unix Timestamp Converter

A Unix timestamp is the number of seconds that have elapsed since 00:00:00 UTC on January 1, 1970 — the "Unix epoch." It is compact, timezone-free, and unambiguous, which is why databases, log files, JWT tokens, cookies, and APIs store time this way. The trouble is that 1752835200 means nothing to a human eye. This Unix Timestamp Converter closes that gap: paste a timestamp and it renders the exact calendar date and clock time in both UTC and your own local timezone, or type a date and get the epoch integer back. Everything runs client-side in your browser using JavaScript's native Date object — no timestamp you enter is ever sent to a server, logged, or stored, which matters when the value you are decoding came from a production database or an authentication token. The converter detects whether your input is in seconds (10 digits) or milliseconds (13 digits), since JavaScript, Java, and JavaScript-based APIs commonly use millisecond precision while PostgreSQL, Redis, and most Unix tooling use seconds. It reads your timezone automatically from the browser, so the local time it shows accounts for your current DST offset. Typical users are backend developers cross-checking a `created_at` column against a bug report, DevOps engineers correlating log entries from servers in different regions, QA testers confirming token expiry, and data analysts sanity-checking exported CSVs. A practical tip: when a timestamp decodes to a date in 1970 or the far future, you almost certainly have a seconds-vs-milliseconds mismatch — divide or multiply by 1000. Another: the current live epoch is displayed and ticking, so you can grab "now" for testing without opening a terminal. Because the math is pure integer arithmetic against the epoch, results are instant and identical to what your server's `date` command would produce, just without the round trip. It is a small utility, but for anyone who reads logs it removes a daily point of friction.