Voice & IVR Simulator

Simulate interactive voice response (IVR) phone calls, speech synthesis playback, dial tone audio, and TwiML voice XML execution flows.

The Voice Simulator enables full end-to-end testing of telephony workflows (Twilio Voice, 46elks Voice) directly in your browser without requiring real carrier phone calls.

Realistic Call Screen & Audio Playback

  • Incoming Call State: Simulates incoming calls with pulsating phone ring indicators and interactive "Answer" (Svara) and "Decline" (Avvisa) actions.
  • Browser Speech Synthesis: Reads out voice prompts and text-to-speech instructions using the Web Speech API, with automatic language-first voice matching and selectable custom voice overrides.
  • Call Lifecycle & Auto-Hangup: Automatically transitions to disconnected state and plays standard disconnect tones (425 Hz) when speech finishes or when a <Hangup> command is encountered.

Interactive DTMF Keypad

Test touch-tone IVR menus directly on screen:

  • Standard DTMF Tones: Pressing digits 0-9, *, or # synthesizes authentic dual-tone multi-frequency audio using Web Audio API dual-sine oscillators (ITU-T Q.23 standards).
  • Dial String Display: Displays entered keypad digits for easy verification and debugging of IVR menu choices.

Execution Flow & XML Inspector

Inspect the voice response step by step:

  • Parsed Flow Breakdown: Inspect individual voice actions (<Say>, <Play>, <Gather>, <Dial>, <Hangup>, <Pause>) with their configured parameters.
  • Raw Payload Viewer: Examine original TwiML XML or provider response strings alongside parsed metadata.