Epoch Batch Converter
Convert a list of Unix epoch timestamps to ISO date-times in one click.
Quick answer: Epoch Batch Converter: convert a list of Unix epoch timestamps to ISO date-times in one click. Runs entirely in your browser, free, no signup.
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Unix epoch time counts the seconds elapsed since midnight UTC on 1 January 1970, which makes it the lingua franca for storing timestamps in databases and logs — it is timezone-free, sorts numerically, and needs no locale parsing. The one detail that causes the most bugs is the unit: classic Unix, PostgreSQL and most CLI tools store seconds, while JavaScript's Date.now(), Java and many web APIs use milliseconds. A value that looks a thousand times too large (or a date stuck in 1970) almost always means you picked the wrong unit at the top of the tool.
A quick sanity check helps: a ten-digit number is seconds (good until the year 2286), and a thirteen-digit number is milliseconds. If you see a suspicious date in 1970, your seconds were probably interpreted as milliseconds. Watch out too for the well-known Year 2038 problem, where signed 32-bit second counters overflow — modern systems use 64-bit values, but legacy exports can still truncate.
Because the output is tab-separated, you can paste it straight into a spreadsheet column or a text editor without any cleanup, which is why this format beats copying values one at a time when you are auditing a log dump or reconciling two systems. For converting a single value back and forth, or turning an ISO string into epoch, reach for the timestamp converter; to shift the resulting ISO datetimes into a specific zone, the timezone converter takes over.
Frequently asked questions
- Is the epoch converter free?
- Yes — free with no signup.
- Seconds or milliseconds?
- Pick the unit at the top — JavaScript and most modern APIs use milliseconds; Unix and PostgreSQL default to seconds.
- Are my timestamps uploaded?
- No — every conversion runs in your browser.
- What output format?
- TSV — open in Excel, Google Sheets or any text editor.
- Can I convert ISO back to epoch?
- Use our individual Timestamp Converter for round-tripping.