Unix Timestamp Converter
Timestamp → Date
Paste a Unix timestamp above, or press ⌘↵ to use the current time.
Date → Timestamp
Pick a date and time to get the corresponding Unix timestamp.
Why use a private Unix timestamp converter?
Timestamps turn up in logs, JWT claims, database rows, and API responses — usually next to data you would rather not paste into a random website. formatvault converts them in your browser, so the surrounding context stays private.
It also removes the guesswork that makes timestamps error-prone: seconds vs milliseconds and UTC vs local time are shown side by side.
How it works
The number you enter is classified as seconds or milliseconds by its size and converted with the browser's Date API. Your local time zone comes from your browser settings, so the local time shown is the one you would actually see.
The reverse converter takes a date and time you pick and returns the exact Unix timestamp in both units.
Common use cases
- Reading the exp and iat claims from a JWT
- Converting timestamps in server logs or error reports to readable dates
- Checking created_at and updated_at values stored as integers in a database
- Generating a timestamp for an API request or a test fixture
- Working out how long ago an event happened while debugging
Frequently asked questions
- How does it tell seconds from milliseconds?
- Values below 10,000,000,000 are treated as seconds and larger ones as milliseconds, which is correct for every date from 1970 to the year 2286. You can override the detected unit if you need to.
- Which formats are shown?
- UTC, your local time zone, ISO 8601, and a relative description such as 3 months ago, along with the timestamp in both seconds and milliseconds.
- Can I convert a date back to a Unix timestamp?
- Yes. Pick a date and time and the matching Unix timestamp is shown in both seconds and milliseconds.
- Can I convert dates before 1970?
- Yes. Negative timestamps count backwards from 1 January 1970 UTC and are converted the same way.
- What is the year 2038 problem?
- Systems that store Unix time as a signed 32-bit integer overflow on 19 January 2038 at 03:14:07 UTC. JavaScript dates are not affected, so this converter handles timestamps well beyond 2038.