How do I use SSML with a text-to-speech API?

SSML (Speech Synthesis Markup Language) lets you control how a text-to-speech engine speaks your text—things like pauses, emphasis, pronunciation, rate, pitch, and volume.

Basic idea

Instead of sending plain text, you send XML-like markup:

<speak>
  Hello. <break time="500ms"/> How are you?
</speak>

The TTS API processes the SSML and generates speech accordingly.

Common SSML tags

These are widely supported, though exact support varies by provider:

• <speak>: Root container for SSML
• <break time="..."/>: Pause
• <emphasis level="strong">...</emphasis>: Stress words
• <prosody rate="slow" pitch="+2st">...</prosody>: Change speaking style
• <say-as interpret-as="characters">TTS</say-as>: Spell out text
• <phoneme ph="...">...</phoneme>: Control pronunciation
• <sub alias="...">...</sub>: Replace spoken form
• <lang xml:lang="...">...</lang>: Switch language

Example

<speak>
  <prosody rate="medium">
    Welcome to our service.
  </prosody>
  <break time="300ms"/>
  <emphasis level="moderate">Please</emphasis> review your settings.
  Your order number is <say-as interpret-as="digits">12345</say-as>.
</speak>

Typical API usage

Most TTS APIs work like this:

1. Choose a voice/model
2. Mark the request as SSML or provide an SSML-specific field
3. Send the SSML text
4. Receive audio output

Example request body

{
  "voice": "en-US-Standard-C",
  "input_type": "ssml",
  "text": "<speak>Hello <break time='300ms'/> world.</speak>"
}

Important notes

• Your SSML must be valid XML.
• Escape special characters like &, <, and > when they appear in normal text.
• Not every API supports every SSML tag.
• Some providers use slightly different syntax or have proprietary extensions.

Best practices

• Keep markup simple unless you need fine control.
• Test on your target voice/provider; SSML rendering can differ.
• Use pauses and emphasis sparingly so speech still sounds natural.

If you tell me which TTS provider you’re using (Google, AWS Polly, Azure, ElevenLabs, OpenAI, etc.), I can give you the exact SSML format and an example request.