Chrome / WebKit Timestamp Converter
Convert a Chrome/WebKit timestamp — microseconds since January 1, 1601 UTC — to a Unix timestamp and readable date. Common in Chrome history, cookies, cache, and other SQLite-backed browser artifacts.
What is a Chrome / WebKit timestamp?
Chromium and WebKit store many times as the number of microseconds since January 1, 1601 UTC. You will encounter these 17-digit values in the History, Cookies, and Login Data SQLite databases, which makes this format common in browser forensics and data export debugging.
- Epoch: 1601-01-01 00:00:00 UTC (same base as Windows FILETIME)
- Resolution: microseconds (1,000,000 per second)
- A present-day value is a 17-digit number around 1.3 × 10^16
- Seen in: Chrome/Edge/Brave History (visits.visit_time), Cookies (creation_utc), cache entries
How to convert a WebKit timestamp to Unix time
A WebKit timestamp is microseconds since 1601. Divide by 1,000,000 to get seconds since 1601, then subtract the 11,644,473,600-second gap to the Unix epoch.
- Unix seconds = WebKit / 1000000 − 11644473600
- Unix milliseconds = WebKit / 1000 − 11644473600000
- Example: 13344473600000000 → 1700000000 → 2023-11-14 22:13:20 UTC
- SQLite: datetime(visit_time/1000000 - 11644473600, "unixepoch")
Edge cases
A WebKit timestamp of 0 means 1601-01-01, which usually represents a null or unset value rather than a real visit. The microsecond precision exceeds JavaScript safe integers, so this converter parses with BigInt and keeps full accuracy down to the millisecond.
- Do not confuse the microsecond-since-1601 format with plain Unix microseconds — they differ by the 1601→1970 offset
- All WebKit times are UTC; choose a display timezone after converting
- Some Chrome fields (e.g. last_visit_time = 0) are sentinels for "never"
- What epoch does Chrome use for timestamps?
- Chromium/WebKit timestamps count microseconds since January 1, 1601 00:00:00 UTC — the same epoch as Windows FILETIME, but in microseconds rather than 100-nanosecond ticks.
- How do I convert a Chrome history timestamp?
- Divide the value by 1,000,000 and subtract 11,644,473,600 to get a Unix timestamp in seconds, then format it as a date.
- Why is the Chrome timestamp 17 digits?
- Because it counts microseconds (a millionth of a second) since 1601, accumulating over 400 years of microseconds produces a 17-digit number.