Clock

By default the clock reads the system time of the machine running the browser. If that machine's clock is off, the one on stream is off by exactly the same amount. Turning on Time Sync fetches accurate time from the server and adds the difference back in when rendering

The feature is off by default and lives under Settings - General - Time Sync. It is recommended for Windows users

How It Works

Sync uses the NTP 4-timestamp algorithm, deriving the gap between the local clock and the server from four points in time:

Which gives:

offset = ((t1 - t0) + (t2 - t3)) / 2
rtt    = (t3 - t0) - (t2 - t1)

Because the round trip is subtracted before the offset is computed, network latency never leaks into the result. Each sync takes two samples 100ms apart and keeps the one with the lowest round trip — the lower the latency, the closer the measured offset is to the truth

The first sync runs the moment you enable it, then repeats automatically every hour. Resync triggers one by hand

Status Readout

Once enabled, the result of the latest sync appears beside the switch:

• RTT — round-trip time in milliseconds. Lower means a more trustworthy measurement
• Offset — the gap between the local clock and the server in milliseconds. A positive number means the local clock is running behind
• Syncing… — samples are in flight
• Sync failed — the request did not complete. The clock falls back to local system time and retries on the next scheduled sync

Privacy and Caveats

• This feature sends your local time (a Unix timestamp) to Cloudflare for calibration, and nothing else
• Sync only affects what the clock displays. It never changes your system time
• Timezone and sync are independent: sync corrects what time it is, while Timezone decides which region to show it for

Related Links

• Settings - Timezone and the rest of the options
• Using It in OBS - Getting the configured address into OBS