Skip to main content
When starting a Tavus conversation, reducing both perceived and actual latency creates a smoother, more professional user experience. Below are two key strategies to optimize startup latency.

​
1. Add a Hair Check

The goal is to wait until the PAL has actually joined before dropping the user into the live room, so the experience feels instant instead of “loading / awkward silence.” Tavus provides a ready-made Hair Check block you can plug into your application. The Hair Check component shows a pre-call interface where users can test and configure their audio/video devices while the PAL joins the room in the background. Waiting for the PAL to join: Before transitioning from the Hair Check screen to the live conversation, wait for the participant-joined event from Daily. In a Tavus CVI one-to-one conversation, any participant that joins that is not the ‘local’ participant is the face. 
// Using Daily participant-joined event
callObject.on('participant-joined', (event) => {
  const participant = event.participant;
  // Filter out 'local' participant - any non-local participant is the face
  if (participant.id !== 'local') {
    // Face has joined, safe to transition user to conversation
    setScreen('call');
  }
});
You can also use the participant.user_name property to identify the face, or listen for the system.pal_joined webhook callback if you’ve set a callback_url when creating the conversation. Tavus also sends a legacy duplicate system.replica_joined with the same payload. For the webhook approach, see Webhooks and Callbacks for details on system.pal_joined. Additionally, system.pal_joined (and legacy system.replica_joined) are broadcast as Tavus app-events over Daily’s data channel. You can listen for Daily app-message events and check event_type === "system.pal_joined" if you prefer in-call event handling rather than webhooks. Benefits:
  • Users see an active interface instead of a loading screen
  • Device permissions are handled before joining
  • The PAL has time to fully join before the user enters
  • Creates a seamless, instant-feeling transition
Implementation: 
npx @tavus/cvi-ui@latest add hair-check-01

import { HairCheck } from './components/cvi/components/hair-check';

<HairCheck
  isJoinBtnLoading={isLoading}
  onJoin={handleJoinCall}
  onCancel={handleCancel}
/>
Example Implementation: You can try the Hair Check experience and clone the complete working example from the CVI UI Haircheck Conversation Example. The example includes both the Hair Check and Conversation components set up together. For complete setup instructions and component details, see the Hair Check block documentation.

​
2. Add a Network Check for Proactive Troubleshooting

Daily provides network connectivity test components you can run before joining to detect common issues (bandwidth, network connectivity, etc.). The most comprehensive pre-call test. It automatically connects to a Daily room, streams video, and collects outbound WebRTC stats for up to 30 seconds. Returns:
  • "good": Network conditions are optimal
  • "bad": Network conditions are poor
  • "warning": Network conditions may cause issues
  • "aborted": Test was interrupted
  • "failed": Test failed to complete
Usage: 
import DailyIframe from '@daily-co/daily-js';

const callObject = DailyIframe.createCallObject();

// Run test before joining
const result = await callObject.testCallQuality();

if (result.result === 'good') {
  // Proceed with joining the conversation
  await callObject.join({ url: conversationUrl });
} else if (result.result === 'bad' || result.result === 'warning') {
  // Display user-facing message about poor connection
  showConnectionWarning('Your connection quality may affect your experience. Consider improving your network connection.');
  // Optionally proceed anyway or block joining
  await callObject.join({ url: conversationUrl });
} else {
  // Handle failed or aborted tests
  console.warn('Network quality check:', result.result);
}
User messaging: Use the test results to inform users about their connection quality. When the result is "bad" or "warning", display a message letting them know their connection is poor and may affect their experience. This helps set expectations and allows users to improve their network before joining. Benefits:
  • Detects bandwidth issues before the user joins
  • Identifies network connectivity problems
  • Provides actionable feedback about network conditions
  • Allows you to set user expectations about connection quality
  • Reduces failed connection attempts and user frustration
For more details, see the Daily testCallQuality documentation.

​
Summary

Combining these two strategies significantly improves the startup experience:
  1. Hair Check - Masks loading time with an active interface
  2. Network Testing - Proactively identifies and handles connectivity issues
Together, these approaches reduce both perceived latency (what users experience) and actual latency (technical performance), creating a smoother, more professional conversation startup.