How do I troubleshoot common problems with Twilio Client?

Twilio Client Pre-Launch Checklist

We recommend going through the checklist below before rolling out your Twilio Client application:

1. Open network ports in your router / firewall / antivirus software. Check out the FAQ What are Twilio Client's network connectivity requirements? for all the detailed port/bandwidth/firewall info.

2. If your router supports QoS, prioritize the ports from step 1, or the IP address of the computer(s) making Client calls.

3. Visit and place a test call. Verify two-way audio. If desired, run a bandwidth test to determine Client call capacity for your network.

Twilio Client Troubleshooting Guide

Below you can find some troubleshooting steps to resolve common problems we've seen with Twilio Client.

If Twilio Client cannot establish a call:

  • Check open network ports in your router / firewall / antivirus software (step 2 in pre-launch checklist)
  • Confirm a network connection is currently available
  • Review the javascript console for application errors

If no audio or one-way audio is experienced in a Client call: 

  • Check open network ports in your router / firewall / antivirus software (step 2 in pre-launch checklist)
  • Confirm the hardware is correctly attached and ensure the correct microphone and speakers are selected in software settings
  • Check to ensure the microphone is not muted (some have a hardware mute button) and the speaker volume is turned up

If call audio has dropouts:

  • Twilio Client requires a high speed and low latency network connection.  Benchmark the network using Ping test and/or Speed test and aim to improve the scores.
  • Enable router QoS or prioritize traffic for Twilio Client (step 3 in pre-launch checklist)
  • Reduce network activity not related to VoIP or use a separate network for VoIP workstations

If call audio is garbled:

  • Use a headset instead of built in computer microphone
  • Reduce ambient noise such as nearby speakers or fans
  • Adjust the distance of the microphone from the mouth - too close can cause audio clipping
  • Adjust microphone levels in the computer’s sound settings
  • Ensure computer has resources available to process a call
    • CPU and RAM are not overutilized
    • Close un-needed applications and browser tabs
    • Try disabling antivirus software

If my microphone level is changing on its own:

Some device drivers do not behave properly for auto-gain control. If you have noticed that your microphone level is self-adjusting, consider overriding the WebRTC defaults in order to force the AGC to be turned off, regardless of system wide settings. You can do this by specifying googAutoGainControl when calling the setup function, as follows:

Twilio.Device.setup(token, {
    audioConstraints: {
        mandatory: { 
            googAutoGainControl: false 

For the complete list of audioConstraints, please refer to the FAQ How to constrain the audio sources in Google Chrome?.

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