Compare AI TTS Models (2025)

Modern TTS offers lifelike prosody, multilingual support, and voice cloning. This guide compares popular providers and shows how to call them through one API.

Always review provider licenses for commercial and cloning use. Latency and quality vary by model and voice.

At‑a‑glance

Feature comparison

Unified API examples

ElevenLabs TTS — JavaScript

import axios from "axios";

const res = await axios.post(
  "https://api.coreapi.com/v1/elevenlabs/tts",
  {
    text: "Welcome to Core API, your unified gateway to AI models.",
    voice_id: "Rachel",
    model_id: "eleven_monolingual_v1",
  },
  {
    headers: { Authorization: `Bearer ${process.env.CORE_API_KEY}` },
    responseType: "arraybuffer",
  }
);
// Save res.data to an .mp3 file

ElevenLabs TTS — Python

import requests, os

r = requests.post(
    "https://api.coreapi.com/v1/elevenlabs/tts",
    json={
        "text": "Welcome to Core API, your unified gateway to AI models.",
        "voice_id": "Rachel",
        "model_id": "eleven_monolingual_v1",
    },
    headers={"Authorization": f"Bearer {os.environ['CORE_API_KEY']}"},
)
open("speech.mp3", "wb").write(r.content)

Azure Neural TTS — JavaScript

import axios from "axios";

const res = await axios.post(
  "https://api.coreapi.com/v1/azure/speech",
  {
    text: "Thanks for listening. This is Azure Neural TTS via Core API.",
    voice: "en-US-JennyNeural",
    format: "audio-24khz-48kbitrate-mono-mp3",
  },
  {
    headers: { Authorization: `Bearer ${process.env.CORE_API_KEY}` },
    responseType: "arraybuffer",
  }
);

Azure Neural TTS — Python

import requests, os

r = requests.post(
    "https://api.coreapi.com/v1/azure/speech",
    json={
        "text": "Thanks for listening. This is Azure Neural TTS via Core API.",
        "voice": "en-US-JennyNeural",
        "format": "audio-24khz-48kbitrate-mono-mp3",
    },
    headers={"Authorization": f"Bearer {os.environ['CORE_API_KEY']}"},
)
open("azure-tts.mp3", "wb").write(r.content)

Choosing a provider

• Prefer ElevenLabs for premium expressiveness and cloning workflows.
• Prefer Azure for SSML control and broad language coverage.
• Prefer Google/Polly for utility voice, predictable costs, and scale.