Timestamp Converter Online (100% Free & Private)
Free timestamp converter that runs in your browser. No sign-up, no install.
Unix Timestamp Converter
Convert epoch seconds or milliseconds to a date and back, in any time zone.
Timestamp to date
Date to timestamp
A Unix timestamp counts seconds (or milliseconds) since 1970-01-01 00:00:00 UTC and has no time zone of its own. The zone you pick only changes how it is displayed or how typed clock time is read. Auto-detect guesses the unit from the size of the number (up to 11 digits is seconds, 12 to 14 digits is milliseconds), so if your value is unusual, choose the unit yourself. Leap seconds are not counted, as in standard Unix time.
What this tool does and who it is for
This converter turns Unix timestamps into readable dates and dates back into timestamps. Choose seconds, milliseconds, microseconds or nanoseconds yourself, or leave Auto-detect on and the tool explains how it guessed.
Pick any time zone (your local one, UTC or any IANA zone such as America/New_York) to see the result as ISO 8601, RFC 2822, a readable date and relative time. In the other direction, type a date and choose which zone it should be read in.
Everything is calculated in your browser using its time zone data.
Official Formula / Technical Standard
Real-World Worked Scenario
Paste your input code or payload to inspect, format, validate, or convert data with instant syntax verification.
When people use it
Reading a timestamp from a log or API
Paste 1772872800 or 1772872800123 and see the date in UTC and in your own zone.
Fixing a seconds versus milliseconds mix-up
If a date comes out in 1970 or in the year 50000, switch the unit and compare.
Converting a meeting time for a server
Enter a date in New York time and get the exact epoch value in seconds and milliseconds.
Checking when something happened relative to now
The relative time line shows how long ago or how far ahead a timestamp is.
Notes for US users
- US time zones switch for daylight saving on the second Sunday in March and the first Sunday in November. A clock time in the skipped hour does not exist and one in the repeated hour happens twice; the tool tells you when that applies.
- Unix time is always UTC-based. Converting to Eastern, Central, Mountain or Pacific is only a display choice.
- Databases and APIs differ: JavaScript and Java use milliseconds, while most Unix tools and many APIs use seconds.
Limits and what to double-check
- •Auto-detect guesses from the size of the number (up to 11 digits is seconds, 12 to 14 is milliseconds, 15 to 17 is microseconds, more is nanoseconds). Unusual dates far in the past or future can be misread, so choose the unit yourself.
- •Typed dates need the format YYYY-MM-DD HH:mm:ss (or ISO 8601 with T). Other formats are rejected rather than guessed.
- •Precision is limited to JavaScript numbers, so nanosecond values are shown to the millisecond. Leap seconds are not counted, as in standard Unix time.
Expert Best Practices & Common Pitfalls
Recommended Best Practices
- •Validate data schemas against official specification standards before production deployment.
- •Keep sensitive API keys and production credentials out of external browser clipboards.
- •Use automated formatters to maintain clean code consistency across development teams.
Common Mistakes to Avoid
- •Pasting production API keys or customer data into unsecured cloud utility sites.
- •Ignoring syntax error diagnostics and warnings highlighted by parsers.
- •Assuming encoded data like Base64 provides cryptographic security.
Features & Security Architecture
- 100% Client-Side: Zero server uploads ensure complete privacy and data confidentiality
- Fast Results: Processing happens on your own device, so there is no upload or server queue to wait for
- No Sign-Up Required: Completely free to use with no daily usage caps or account requirements
- Works on All Devices: Fully responsive across desktop, tablet, and mobile browsers
Frequently Asked Questions
How does the Timestamp Converter work?▼
The Timestamp Converter runs 100% inside your web browser using modern client-side JavaScript. It performs calculations, conversions, and document processing locally on your device without sending any data to external servers.
Is this timestamp converter completely free to use?▼
Yes. This tool is completely free with no usage limits, no subscriptions, and no registration required.
Is my data private when using the Timestamp Converter?▼
Yes. Because all operations execute locally on your computer or phone, your inputs, documents, and data never leave your browser.
How do I tell seconds from milliseconds?▼
Current timestamps in seconds have 10 digits and in milliseconds have 13. The auto-detect mode applies that idea and shows its reasoning. You can override it with the unit menu.
Does a Unix timestamp have a time zone?▼
No. It counts time since 1970-01-01 00:00:00 UTC. The zone you pick only changes how it is displayed or how a typed date is interpreted.
What is the difference between ISO 8601 and RFC 2822?▼
ISO 8601 looks like 2026-03-07T08:40:00Z and is common in APIs and JSON. RFC 2822 looks like Sat, 07 Mar 2026 08:40:00 +0000 and is used in email headers and HTTP-style dates.
Why is my typed date flagged as not existing?▼
In spring, clocks jump forward, so some times such as 2:30 AM on that Sunday in US zones never occur. Choose another time or zone.
Can it handle dates before 1970?▼
Yes. Negative timestamps map to dates before 1970 within the range JavaScript supports.