Unix Timestamp Converter
Convert Unix timestamps to human dates and back — auto-detecting seconds, milliseconds, microseconds, nanoseconds or ISO strings. See the instant across timezones live, get ISO/RFC/relative forms, calendar facts and a custom format, then copy or pipe the JSON. Runs entirely in your browser.
About this ToolHow it works, benefits & use casesTap to collapse
Epoch numbers are everywhere — log lines, JWT claims, database columns, API payloads — and this converter turns them into something you can actually read. Paste a Unix timestamp and it auto-detects whether you gave it seconds, milliseconds, microseconds or nanoseconds (or force a unit if the magnitude is ambiguous), then shows the instant as ISO 8601 in UTC and local time, RFC 2822, a relative phrase like "3 hours ago", and the raw value in every other unit. It also accepts ISO strings and the word "now", and a date picker lets you go the other way. A live clock shows the current time, calendar facts (day of week, day of year, ISO week, quarter, leap year) appear for any instant, and the same moment is rendered across multiple timezones you can add or remove. Everything runs in your browser and exports as JSON.
How to Use
- 1Type or paste a value into the "Timestamp or date" box — a Unix timestamp in any unit, an ISO 8601 string, or "now".
- 2If auto-detection guesses the wrong unit, switch the s / ms / µs / ns toggle to force how the number is read.
- 3Or use the "Pick a date" calendar input to convert a specific date and time the other way.
- 4Copy any output card (Unix seconds, milliseconds, ISO, RFC 2822, relative, micro/nanoseconds) with a click.
- 5Add timezones from the "+ Add timezone" menu to see the same instant in each, and set a date-fns format string for a custom output.
- 6Copy, download, or pipe the full breakdown as JSON to the JSON Formatter or JSON to TypeScript.
Key Benefits
- Auto-detects seconds, milliseconds, microseconds, or nanoseconds — or force the unit
- Outputs ISO 8601 (UTC and local), RFC 2822, and a human relative phrase at once
- Live current-time readout in Unix seconds and ISO 8601
- Renders the same instant across multiple timezones you choose
- Calendar facts: day of week, day of year, ISO week number, quarter, and leap year
- Custom date-fns format string plus a list of common presets
- Shareable URL and JSON export that pipes into other tools
Common Use Cases
- Decoding a Unix timestamp from a log line, database row, or JWT exp/iat claim
- Converting a human date back into the epoch value an API expects
- Checking what local time a UTC timestamp maps to for users in other regions
- Sanity-checking whether a millisecond value was accidentally treated as seconds
- Generating a formatted date string with custom tokens for a report or filename
Unix seconds
—ISO 8601
—Paste a Unix timestamp (any unit), an ISO 8601 string, or “now”.
Showing the current time — type above to convert a specific instant.
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Auto mode detects the unit by magnitude — a 10-digit number reads as seconds, 13 digits as milliseconds, and larger values as microseconds or nanoseconds. When a number is ambiguous you can override the guess with the s / ms / µs / ns toggle to force a specific unit.
Yes. Use the "Pick a date" calendar input, or paste an ISO 8601 string into the main box. The tool then shows the corresponding Unix value in seconds, milliseconds, microseconds, and nanoseconds, each copyable with one click.