Troubleshoot authentication timing
A wrong system clock can break one-time codes or certificate checks.
Time & Date Tools
Clock Accuracy Test
Measure the difference between the operating-system clock and network time. The tool never changes device settings; it reports the offset, measurement quality and general correction steps.
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What this tool does
Take repeated samples and favor the lowest-latency results.
Show fast/slow offset in milliseconds or seconds with a quality grade.
How to use it
- 1Start the test and keep the page in the foreground for a few seconds.
- 2Wait for all samples, then read the best latency and offset.
- 3If the offset is large, enable automatic date and time in the operating system.
- 4Run the test again after changing settings to confirm the difference is smaller.
Practical uses
Compare logs and recordings
Check whether computers, phones and cloud records use different time bases.
Compatibility, privacy and limits
Processed in your browserHTTPSMobile + Desktop
Quality depends on latency and jitter. Corporate proxies, VPNs, power-saving modes or background tabs may reduce accuracy. A web page cannot change the system clock.
Frequently asked questions
How much offset is serious?
Tens or hundreds of milliseconds are usually unnoticed in everyday use; authentication, logs and regulated workflows should follow their own requirements.
Why is latency high on a VPN?
A VPN may route traffic through a distant server and add delay and jitter.
Can this result be legal evidence?
No. It is a browser network measurement, not an audited or certified timestamp.
How do I correct a phone clock?
Enable automatic date/time and automatic time zone in system settings; exact labels vary by platform.