CALLCHECK

CALLCHECK

Is your connection ready for calls?

Connection type
Ready
Latencyspeed
Jitterwaves
Packet Losserror_outline
MOS Scoreequalizer

Latency over time

Awaiting test
Signal Quality
Score

// Awaiting test

What are we measuring?

CallCheck runs 20 timed requests to Google's servers and uses the results to estimate how your connection will handle a real voice or video call.

speed
Latency
How fast data travels to a server and back

Latency is the delay between you speaking and the other person hearing it. Low latency makes conversations feel natural. High latency causes awkward pauses where you both start talking at the same time.

Under 150ms~ 150–300msOver 300ms
waves
Jitter
How much your latency fluctuates

Jitter happens when data packets arrive unevenly. Even if your average latency is fine, big swings between packets make audio sound choppy or robotic. A stable connection has low jitter.

Under 30ms~ 30–50msOver 50ms
error_outline
Packet Loss
Data that never arrives

Every call breaks your voice into small chunks (packets) sent over the internet. If some don't arrive, you hear gaps or the audio cuts out. Even 1–2% loss is noticeable on calls.

Under 1%~ 1–3%Over 3%
equalizer
MOS Score
The overall verdict for your call quality

MOS (Mean Opinion Score) is the industry-standard measure for voice call quality, rated 1–5. It combines latency, jitter, and packet loss into one number using a formula developed by the ITU. Anything above 4.0 is considered excellent.

4.3 – 5.0~ 3.1 – 4.2Below 3.1
How the test works · CallCheck sends 20 timed HTTP requests to Google's connectivity servers over about 10 seconds and measures how long each round trip takes. Jitter is calculated from how much those times vary. Packet loss is counted when a request times out. No audio or video is captured — no microphone or camera access is needed.