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Unix Timestamp Converter

Every format at once, real timezone handling, and a batch mode for log files.

Also known as: Epoch converter, Unix time converter, Timestamp to date converter

100% FreeNo Signup RequiredEvery Format at OnceBatch Conversion
100% local — nothing you enter here ever leaves this browser tab
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Step by step

How it works

  1. 1Paste a Unix timestamp (seconds or milliseconds — it's auto-detected), or pick a date and time instead.
  2. 2Read the converted value in ISO 8601, RFC 2822, SQL datetime, and both Unix units at once.
  3. 3Select a timezone to see the exact local date and time in that zone.
  4. 4For multiple values, switch to batch mode and paste a list, one timestamp per line.
Why OTL

Why use Unix Timestamp Converter

Every format shown at once

ISO 8601, RFC 2822, SQL datetime, Unix seconds, and Unix milliseconds all displayed simultaneously — no format switcher.

Auto-detects seconds vs. milliseconds

Paste a raw number and it's correctly interpreted based on digit count, instead of guessing or checking a lookup table.

Real timezone conversion

See the exact date and time in any timezone, computed with the browser's own Intl API, including correct daylight saving time handling.

Batch mode for log files

Paste a whole list of timestamps and convert every one at once, instead of one at a time.

Live current timestamp

A constantly updating current Unix timestamp, one click away from being used as your starting point.

Nothing uploaded

Every conversion runs locally in your browser using standard JavaScript date APIs.

Real-world use

Who uses Unix Timestamp Converter

Debugging an API response

Convert a timestamp field from a JSON response into a readable date to check if it's the value you expect.

Reading log files

Batch-convert a list of Unix timestamps pulled from server logs into readable dates at once.

Checking a JWT's expiration

Convert a token's exp or iat claim (a Unix timestamp) into a readable date to confirm when it expires.

Writing a SQL query

Get a timestamp in SQL datetime format, ready to paste directly into a WHERE clause.

Coordinating across timezones

Check what a specific timestamp means in a colleague's or server's timezone before scheduling something.

Generating a timestamp for testing

Pick a specific date and time and get the exact Unix timestamp to use as test or seed data.

Deep dive

About Unix Timestamp Converter

A Unix timestamp — the number of seconds (or milliseconds) since January 1, 1970 UTC — is one of the most common values developers need to convert back and forth, whether debugging an API response, reading a log file, or checking when a JWT expires. It's also a value that's genuinely easy to get wrong: seconds versus milliseconds, which timezone a displayed date actually represents, and which of several nearly-identical date string formats a given system expects.

This tool auto-detects whether a pasted number is in seconds or milliseconds based on its digit count, then shows the same moment in every commonly needed format simultaneously — ISO 8601 (used by most APIs and JavaScript's own Date methods), RFC 2822 (used in email headers and some HTTP contexts), SQL datetime (for pasting directly into a database query), and both Unix seconds and milliseconds — so there's no guessing which format a particular system needs, or re-converting the same value five separate times.

Timezone handling is the other place these tools usually fall short. A timestamp is timezone-agnostic by definition, but reading it as a human date always implies a timezone, and it's easy to misread a UTC time as local time or vice versa. This tool shows the exact date and time in any selected timezone alongside the format table, computed using the browser's own Intl API rather than a hand-rolled offset table that can silently miss daylight saving time transitions.

The batch mode solves a different, very real problem: converting a single timestamp is easy, but converting the fifty scattered through a log file one at a time is tedious. Paste a list, one per line, and every one is parsed and converted at once. Everything runs directly in your browser using the JavaScript Date object and Intl APIs — nothing is ever sent to a server.

Compare

Unix Timestamp Converter vs. other options

How Open Tools Library compares to desktop software and other online tools.

FeatureOpen Tools LibraryDesktop softwareOther online tools
PriceFree, unlimitedN/AUsually free
Formats shown at once5, simultaneouslyN/AOften just 1-2
Batch conversionBuilt inN/ARarely offered
Timezone handlingFull IANA timezone supportN/AOften UTC/local only
Data privacyNever leaves your deviceN/AUsually fine, but varies
Pro tips

Pro tips

  • A 10-digit number is almost always seconds; a 13-digit number is almost always milliseconds — this tool detects that automatically.
  • JavaScript's Date.now() returns milliseconds, while many backend languages and Unix tools default to seconds — check which one a given system expects before pasting a value in.
  • RFC 2822 format is what you'll typically see in email headers (the Date: field) and some older HTTP contexts.
  • SQL datetime format has no timezone information embedded — make sure your database column's timezone assumption matches what you expect.
  • For batch mode, one clean timestamp per line is all that's needed — extra whitespace is trimmed automatically.
Under the hood

Technical specs

Formats shown
ISO 8601, RFC 2822, SQL datetime, Unix seconds, Unix milliseconds
Unit detection
Automatic, based on digit count
Timezone support
Any IANA timezone, via the browser's Intl API
Batch mode
Unlimited timestamps, one per line
Processing location
100% local, in your browser

Privacy & security

Converting a timestamp from an API response or log file shouldn't require sending that data anywhere.

All date and timestamp conversion runs locally using standard JavaScript date APIs.

No account, email, or login required.

Nothing you enter — including batch-converted lists — is stored or logged.

Equally private whether you're converting one timestamp or a few hundred.

FAQ

Frequently asked questions

Is this tool free to use?

Yes, completely free with no limits, and no account needed.

How is my data handled?

All conversion happens locally in your browser using standard JavaScript date APIs — nothing is sent to a server.

What's the difference between Unix seconds and milliseconds?

They represent the same starting point (Jan 1, 1970 UTC) but count at different resolutions — JavaScript's Date.now() returns milliseconds, while Unix system tools and many backend languages default to seconds.

Does this handle dates far in the future or past?

Yes, within the range JavaScript's Date object supports, which covers many thousands of years in both directions.

Can I convert more than one timestamp at a time?

Yes — use the batch conversion box and paste one timestamp per line.

Stuck?

Troubleshooting

My timestamp isn't being recognized

Make sure it's a plain integer (no decimals, commas, or extra text) — a Unix timestamp is just a whole number of seconds or milliseconds.

The date looks off by several hours

This is almost always a timezone mismatch — check which timezone you're viewing the result in, since the same timestamp displays differently in every timezone.

Is a negative timestamp valid?

Yes — negative Unix timestamps represent dates before January 1, 1970, and are handled correctly.

Some lines in batch mode show "invalid"

That line wasn't a plain integer — check for stray text, decimals, or formatting that isn't a valid timestamp.

Ready to use Unix Timestamp Converter?

Free, private, and ready right now — no signup required.

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