Browser Speech Synthesis - Free Version

Purpose

This tool implements text-to-speech conversion based on the browser's native Web Speech API. This API is standardized by W3C and supported by major browser vendors including Microsoft, Google, and Apple. Users can input any Chinese text, select the speech synthesis engine provided by the system, and convert text content into natural and fluent speech playback. It is suitable for accessibility reading, learning assistance, content presentation, and various other scenarios.

Technical Principles

The tool core uses the SpeechSynthesis interface in HTML5's Web Speech API to implement the conversion. This interface allows web applications to convert text into speech output, supporting multiple languages and voices. The speech synthesis engine depends on the voice technology provided by the operating system:

• Windows System: Usually calls Microsoft's speech synthesis engine, including Microsoft XiaoIce, Microsoft Cortana, and other voice technologies
• macOS System: Uses Apple's NSSpeechSynthesizer engine, providing voices like Siri
• Linux System: Depends on system-installed speech synthesizers such as eSpeak, Festival, etc.
• Mobile Devices: iOS uses Apple voices, Android uses Google voice services

No additional plugins or server-side support required, speech synthesis is completed directly in the browser.

Cross-Platform Differences

Due to the dependence on operating system voice engines, there are significant differences in voice quality and tone provided by different platforms:

• Voice Quantity: Windows and macOS typically provide more voice options
• Voice Quality: Voices from commercial operating systems (such as Windows, macOS) are usually more natural
• Language Support: Different systems have varying levels of support for Chinese dialects
• Feature Functionality: Advanced parameter adjustment features have different levels of support across systems

Limitations

Due to browser security policies, the Web Speech API cannot directly provide voice file download functionality. To generate savable audio files, it is recommended to use professional cloud-based TTS services, such as Microsoft Azure Cognitive Services, Alibaba Cloud, Tencent Cloud, and other provided speech synthesis APIs.

Sample Code

// Check browser support
if ('speechSynthesis' in window) {
  // Create speech synthesis instance
  const synth = window.speechSynthesis;

  // Get voice list
  function getVoices() {
    return synth.getVoices();
  }

  // Speech synthesis function
  function speakText(text, voiceIndex) {
    // Create speech instance
    const utterance = new SpeechSynthesisUtterance(text);

    // Set voice (optional)
    const voices = getVoices();
    if (voiceIndex !== undefined && voices[voiceIndex]) {
      utterance.voice = voices[voiceIndex];
    }

    // Set speed, pitch and other parameters
    utterance.rate = 1.0;   // Speed (0.1-10)
    utterance.pitch = 1.0;  // Pitch (0-2)
    utterance.volume = 1.0; // Volume (0-1)

    // Play speech
    synth.speak(utterance);
  }

  // Usage example
  speakText("Welcome to the cross-platform speech synthesis tool");

  // Stop playback
  // synth.cancel();

  // Pause playback
  // synth.pause();

  // Resume playback
  // synth.resume();
}