MongoDB Timestamp Converter
Extract the embedded creation timestamp from a MongoDB ObjectId, or generate a valid-looking ObjectId for a specific date and time.
Recommended Settings
Pro Tips
- •Edit either the MongoDB ObjectId or the date/time field - the other one updates automatically
- •Use the Copy buttons to grab any value in the format you need, including Unix seconds, milliseconds, or ISO 8601
- •Click Use Current Time to instantly see the current moment represented in this format
- •This runs entirely in your browser - nothing you enter is sent to a server
Most Popular
Most users paste in a raw value from a database or log file to see what date and time it actually represents
When to Use This Tool
Convert a raw MongoDB ObjectId into a readable date and time.
Work backward from a known date to the equivalent MongoDB ObjectId.
Quickly verify what a specific timestamp value actually represents.
Figure out why a timestamp value looks wrong by converting it to a human-readable date.
How It Works
Take the MongoDB ObjectId you enter, which represents a 24-character hex string whose first 8 characters (4 bytes) encode the number of seconds since the Unix epoch
Convert it to a standard Unix millisecond timestamp using the correct epoch offset and unit scale
Display the result in several common formats, and support converting in the opposite direction too
100% Private
Files never leave your device. All processing happens locally in your browser.
Lightning Fast
Powered by Client-side epoch arithmetic for optimal performance on modern browsers.
Open Source
Built with verified, open-source libraries. Fully transparent.
Frequently Asked Questions
What epoch does this format use?
A 24-character hex string whose first 8 characters (4 bytes) encode the number of seconds since the Unix epoch.
Why would I need to convert this format?
A MongoDB ObjectId is 12 bytes total: a 4-byte timestamp, a 5-byte random value, and a 3-byte incrementing counter - only the timestamp portion is meaningful here, so a generated ObjectId's remaining bytes are random and won't match a real document.
Is my data sent to a server?
No. All conversion happens entirely in your browser using JavaScript.
Does this account for timezones?
The underlying timestamp is timezone-independent (a single point in time), and the 'Date & Time' field shows it in your browser's local timezone alongside UTC for reference.
What if I enter an invalid value?
The tool will show a warning that the value doesn't look valid rather than silently displaying an incorrect date.