Google TTS Neural2

Google Speech synthesisSSML

Input$16/M

Context4K

Provider list prices: no platform markup, pay-as-you-go. These are official list prices. Logged-in customers may see effective prices including workspace discounts on /console/pricing.

Use Google TTS Neural2 in 30 seconds

OpenAI-compatible: swap the base_url, keep your SDK. POST /v1/chat/completions

from openai import OpenAI

client = OpenAI(
    base_url="https://synthorai.io/v1",
    api_key="sk-syn-...",
)

resp = client.chat.completions.create(
    model="google-tts-neural2",
    messages=[{"role": "user", "content": "Summarize this diff"}],
)
print(resp.choices[0].message.content)

import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://synthorai.io/v1",
  apiKey: "sk-syn-...",
});

const resp = await client.chat.completions.create({
  model: "google-tts-neural2",
  messages: [{ role: "user", content: "Summarize this diff" }],
});
console.log(resp.choices[0].message.content);

curl https://synthorai.io/v1/chat/completions \
  -H "Authorization: Bearer sk-syn-..." \
  -H "Content-Type: application/json" \
  -d '{
    "model": "google-tts-neural2",
    "messages": [{"role": "user", "content": "Hello"}]
  }'

package main

import (
	"context"
	"fmt"

	"github.com/openai/openai-go/v3"
	"github.com/openai/openai-go/v3/option"
)

func main() {
	client := openai.NewClient(
		option.WithBaseURL("https://synthorai.io/v1"),
		option.WithAPIKey("sk-syn-..."),
	)
	resp, _ := client.Chat.Completions.New(context.TODO(), openai.ChatCompletionNewParams{
		Model: "google-tts-neural2",
		Messages: []openai.ChatCompletionMessageParamUnion{
			openai.UserMessage("Summarize this diff"),
		},
	})
	fmt.Println(resp.Choices[0].Message.Content)
}

import com.openai.client.OpenAIClient;
import com.openai.client.okhttp.OpenAIOkHttpClient;
import com.openai.models.chat.completions.*;

OpenAIClient client = OpenAIOkHttpClient.builder()
    .baseUrl("https://synthorai.io/v1")
    .apiKey("sk-syn-...")
    .build();

ChatCompletion resp = client.chat().completions().create(
    ChatCompletionCreateParams.builder()
        .model("google-tts-neural2")
        .addUserMessage("Summarize this diff")
        .build());
System.out.println(resp.choices().get(0).message().content().orElse(""));

Specs & limits

Audio

Languages: A much shorter locale list than Standard. Neural2 voice ids are published for da-DK, de-DE, en-AU, en-GB, en-IN, en-US, es-ES, es-US, fr-CA, fr-FR, hi-IN, it-IT, ja-JP, ko-KR, pt-BR, th-TH and vi-VN. Google notes Neural2 voices are available on global and single-region endpoints.
Audio limits: Content limit of 5,000 total bytes per synthesize request. Output LINEAR16 (with a WAV header), MP3 at 32 kbps, OGG_OPUS, or G.711 MULAW and ALAW
optional sampleRateHertz resamples and fails the request if the rate is unsupported for the encoding. Not offered over streaming synthesis. Billed per character including spaces and newlines, with all SSML tags except <mark> counted
the multi-byte-counts-once note applies to Standard and WaveNet only

Realtime

Voices: Voice ids follow the locale-plus-letter pattern (en-US-Neural2-F, ja-JP-Neural2-B). Google's comparison table lists Neural2 as general purpose, generally available, controllable via SSML and not streaming-capable, and the docs state the voices are based on the same technology used to create a Custom Voice, letting anyone use Custom Voice technology without training their own.
Session: AudioConfig controls: speakingRate 0.25 to 2.0 (1.0 native)
pitch -20.0 to 20.0 semitones
volumeGainDb -96.0 to 16.0
effectsProfileId device profiles for wearable, handset, headphone, small and medium Bluetooth speaker, large home entertainment, large automotive and telephony playback
SSML tags include speak, break, say-as, sub, mark, prosody, emphasis, phoneme, voice and lang

Model

Modalities: text → audio

The Neural2 voice tier of Google Cloud Text-to-Speech, still grouped under Legacy TTS models on the pricing page. US$0.000016 per character (US$16 per 1 million characters) with the first 1 million characters free each month, against Standard's 4 million.

per Google official docs ↗

About Google TTS Neural2

Custom voice technology without training a custom voice

Much shorter locale list than standard

General purpose and ssml controllable, but no streaming

Google TTS Neural2 exposes the Neural2 voice tier of Google Cloud Text-to-Speech, and Google's description of it is unusually specific about where the voices come from: Neural2 voices are based on the same technology used to create a Custom Voice, and the tier exists so that anyone can use Custom Voice technology without training their own custom voice.

The comparison table calls it general purpose, marks it generally available, and gives its controllability as SSML, the same profile Standard and WaveNet carry.
Price is where the tier declares itself, at US$0.000016 per character, quoted as US$16 per 1 million characters, with the first 1 million characters each month free rather than Standard's 4 million; the pricing page still groups it under Legacy TTS models.
The trade for that quality is reach.
Where Standard spans locales from Afrikaans to Cantonese, Neural2 voice ids appear for a much shorter list, da-DK, de-DE, en-AU, en-GB, en-IN, en-US, es-ES, es-US, fr-CA, fr-FR, hi-IN, it-IT, ja-JP, ko-KR, pt-BR, th-TH, and vi-VN, named in the familiar locale-plus-letter form such as en-US-Neural2-F.
Google notes Neural2 is available on global and single-region endpoints.
Everything operational is shared with the rest of the classic API: SSML input, speakingRate from 0.25 to 2.0, pitch in semitones across a 20-point range either way, volumeGainDb from -96 to 16, an optional synthesis sample rate, the device profiles from wearables through telephony, and output as LINEAR16, MP3, OGG_OPUS, MULAW, or ALAW.
The same 5,000-byte content ceiling per request applies, and like Standard, Neural2 is not offered over streaming synthesis, which is the concrete capability you give up against Chirp 3: HD.
Billing counts characters including spaces and newlines, with all SSML tags except mark counted.
Synthorai serves it over the OpenAI-compatible /v1/audio/speech endpoint.

Official Google docs ↗

FAQ

Is the Google TTS Neural2 API free to try?

Yes: new accounts get 10 trial calls and up to $1 in free credit, no card required. At $16/M input tokens, that credit alone covers roughly 15 requests of ~4K tokens against Google TTS Neural2.

What is Google TTS Neural2 best at?

Custom voice technology without training a custom voice; much shorter locale list than standard; general purpose and ssml controllable, but no streaming. See the About section for the full picture from the vendor's own release notes.

How much does Google TTS Neural2 cost?

Google TTS Neural2 costs $16 per million input tokens and $0 per million output tokens on Synthorai. That is the provider's list price, with no platform markup.

Does Google TTS Neural2 support prompt caching?

Google TTS Neural2 has no cache-read discount on Synthorai today. Prompt caching still applies to other models on the gateway; see the pricing table for cache-enabled alternatives. Provider caching comparison →

How do I get access to Google TTS Neural2?

Point your existing OpenAI SDK at base_url="https://synthorai.io/v1", set model="google-tts-neural2", and you're done. One API key covers every model on the gateway.

Get your free API key Compare your cost →