Choose a mode
Convert a single epoch, parse an ISO string into epoch values, or paste many numbers at once.
Unix Timestamp Converter
Turn Unix epoch values (seconds or milliseconds) into UTC ISO strings and a readable date in a chosen time zone, or paste an ISO 8601 date to get the epoch. Use batch mode for one value per line—ideal for logs and JSON exports. Everything stays in your browser.
Uses the IANA time zone database. Daylight saving is applied automatically for the region you pick. “Local” follows this device’s clock.
Mode
JSON and JavaScript usually use milliseconds. Some APIs and CLIs use seconds.
Result
Include a Z (UTC) or a numeric offset (e.g. -04:00) so the instant is unambiguous.
Epoch
Up to 500 non-empty lines. Output: input → ISO (UTC) | localized per line.
Batch output
Timestamps and dates are processed only in your browser; nothing is uploaded.
HOW IT WORKS
How to convert Unix time
Unix time counts seconds (or milliseconds) from 1 January 1970 UTC. Pick seconds or milliseconds, choose a zone for readable output, and copy ISO or epoch values for logs, APIs, and databases.
Set units and zone
Match seconds vs milliseconds to your source (CLI vs JavaScript). Pick a time zone for the human-friendly line.
Copy the result
Use UTC ISO for APIs, localized text for reading, or batch lines for spreadsheets.
Why use this tool
Why convert timestamps online?
Logs, webhooks, and JSON fields often carry raw epoch numbers. Converting them quickly—with correct time zones and DST—saves context switching to a shell or spreadsheet.
Debug faster
Turn opaque integers into moments you can read and compare across regions.
Match your stack
Switch between seconds and milliseconds to align with Postgres, JavaScript, or Unix tools.
Batch from logs
Paste many epochs and get one readable block for notes or tickets.
Stay private
Sensitive log lines never leave your device—no paste-to-server risk.
Privacy
Private and secure
All math and formatting run locally. We do not store timestamps or share them with any server.
On-device only
Your input stays in the page until you close the tab.
No account
Use it instantly without signing up or granting permissions beyond the browser.
FAQ
Frequently asked questions
They measure the same instant: seconds are 1000× smaller than milliseconds. JavaScript
Date.now() uses milliseconds; many CLIs and databases use seconds.
The Unix epoch is defined in UTC. The ISO string we show as “UTC” is that instant expressed with a
Z suffix (zero offset).
If the absolute value is at least
1e12, it is treated as milliseconds; otherwise as seconds. Very large second counts may be misread—then pick seconds or milliseconds explicitly.
Without a zone, browsers interpret “local” time differently per user. For a single unambiguous instant, use
Z or an explicit offset like +01:00.
No. Conversion runs entirely in your browser; nothing is sent to TinyDataTool.