Text-to-Speech (TTS) technology is revolutionizing how we interact with digital devices, making experiences more accessible and engaging. Text-to-speech APIs enable applications to communicate complex information in a natural, human-like way. From educational tools and AI support agents to TikTok voiceovers and multimedia presentations, the right TTS API can enhance user experiences and set your application apart.

But with numerous options available, selecting the best TTS API for your needs can feel overwhelming. Some APIs excel at producing high-quality voices, while others specialize in real-time conversational responses. 

This article explores the leading text-to-speech APIs available today—highlighting their unique strengths and weaknesses, and providing insights into the problems they solve, their top use cases, and common considerations for selecting the right provider. By the end of this guide, you'll have a clearer understanding of which TTS API is best suited to meet your needs, whether you're looking for high-quality voice production, real-time conversational AI, or something in between.

What is a Text to Speech API?

A text-to-speech (TTS) API is a software interface that allows developers to convert written text into natural-sounding spoken audio. These APIs provide a way to integrate speech synthesis capabilities into applications, enabling them to generate human-like voices that can read out text content. TTS APIs typically offer a range of voices, languages, and customization options, making it possible to create audio content for various purposes, from accessibility features to voice assistants.

How Text to Speech APIs Work

TTS APIs work by analyzing input text, breaking it down into phonetic components, and applying sophisticated AI language models and speech synthesis algorithms to generate audio output. The process involves several steps, including text normalization, linguistic analysis, and acoustic modeling. Advanced TTS APIs use machine learning techniques to improve the naturalness and expressiveness of the synthesized speech, considering factors like intonation, rhythm, and emphasis.

The Most Important Features of Text to Speech APIs

The most important features of a text-to-speech API include high-quality voice synthesis, support for multiple languages and accents, customizable voice models, real-time synthesis capabilities, and flexible output formats. Additionally, features like SSML (Speech Synthesis Markup Language) support, voice customization options, and the ability to adjust speech parameters such as speed and pitch are valuable for creating more nuanced and tailored audio outputs.

The Top Text to Speech APIs Ranked

Now that you have a better understanding of text-to-speech and how it works, let’s take a closer look at the top providers, common applications, and how they stack up.

1. Deepgram

Deepgram Aura was designed to support high-throughput text-to-speech with minimal latency (<250 milliseconds), making it an excellent choice for real-time applications such as conversational AI and customer support automation. It offers various unique voices optimized for human-like conversations (natural tone, rhythm, and pauses), and scalability with the lowest cost on the market.

Companies like Humach, Phonely, Vapi, and Daily have incorporated our text-to-speech API into their applications to deliver human-sounding agents for a variety of use cases from customer support to healthcare.

Test out Aura’s unique voices here or sign up to build with Aura. If you have questions about how we can support your use case, contact us.

Strengths:

• High throughput and scalability

• Real-time speech processing

• Minimal latency (sub 250 milliseconds)

• High quality voices

• Robust integration capabilities

• Low cost 

Weaknesses: Supports fewer languages compared to other vendors, but will be releasing new languages over the next few months.

Common Use Cases:

• Conversational AI 

• Real-time virtual assistants and AI agents

Key Features:

• Natural-sounding voices with human-like tone, rhythm, and emotion

• Real-time responsiveness (Less than 250 millisecond latency)

• Enterprise-grade scalable API

• Cost-efficient and optimized for high-throughput applications

Price: $0.0150/1k characters

2. ElevenLabs

Elevenlabs is renowned for its high-quality voice cloning and realistic speech synthesis capabilities. This API is ideal for content creators looking to produce professional voice overs for videos, audiobooks, and other multimedia and entertainment projects. 

Pros:

• High quality voice cloning and voices in 30 languages

• AI dubbing capabilities 

• Easy-to-use customization tools

Cons:

• High cost, especially for premium features

• Limited support for real-time applications 

• Lacks stability for scaling real-time traffic

• Voices built for high production use cases, which might not be suitable for conversational AI

Common Use Cases:

• Audiobook narration

• Video voice overs

• Podcast and media production

3. WellSaid Labs

WellSaid Labs offers high-quality, human-like voices, making it a favorite for e-learning, marketing videos, and podcasting. Its user-friendly interface makes it accessible for users with varying technical skills.

Pros:

• 120+ studio-quality voices 

• User-friendly interface

• Easy integration

Cons:

• High latency 

• Lacks stability for scaling real-time applications

• Limited voice customization options

• Higher costs for extensive usage

Common Use Cases:

• E-learning courses

• Marketing and promotional videos

• Podcast voice overs

Pricing: Starts at $49/month, suitable for individuals and small projects.

4. Microsoft Azure

Microsoft Azure's TTS API is part of the larger Azure Cognitive Services suite, offering robust integration with other Microsoft services. Its scalability makes it suitable for enterprise applications.

Pros:

• Extensive language and voice options

• Robust integration with Microsoft services

• Highly scalable

Cons:

• Complex setup and management

• Voices are lower quality (less natural-sounding) 

• Requires familiarity with Azure ecosystem

Common Use Cases:

• Enterprise applications

• Accessibility tools

• IoT devices

Pricing: $15 per 1M characters.

5. PlayHT

PlayHT provides a user-friendly platform with diverse voice options, making it a great choice for content creators focusing on social media videos and educational content. They offer a suite of products including text-to-speech, voice cloning, and an AI Pronunciation Library to ensure proper pronunciation of  brands, industry terminology, and more.

Pros:

• Realistic voice synthesis

• Diverse voice options in 142+ languages

• Easy-to-use platform

Cons:

• High latency

• Limited advanced features

• Lacks stability for scaling real-time applications

Common Use Cases:

• Social media content

• Educational videos

• Podcasts

Pricing: The Basic Plan starts at $19/month, includes limited voice options. The Premium Plan starts at $99/month, includes advanced features and more voices.

6. Speechify

Overview: Speechify focuses on accessibility and personal productivity, offering a straightforward integration process and natural-sounding voices to help users consume content more efficiently.

Pros:

• Accessibility focus

• Easy integration

• Cross-platform support

Cons:

• High latency

• Voice quality may not match top competitors

• Limited advanced customization

Common Use Cases:

• Accessibility tools

• Content consumption

• Personal productivity

Pricing: The Free Plan offers basic features with limited voices. The Premium Plan starts at $139/year, includes access to premium voices and features.

7. Murf

Overview: Murf stands out for its strong emphasis on voice customization and versatility, making it a preferred choice for marketing videos, presentations, and explainer videos.

Pros:

• Versatile voice customization

• High-quality output

• Multi-language support

Cons:

• Costlier for extensive usage

• Limited real-time capabilities

• High latency

Common Use Cases:

• Marketing and promotional videos

• Presentations

• Explainer videos

Pricing: The Basic Plan starts at $13/month, includes basic features and voices. The Pro Plan starts at $26/month, includes advanced features and premium voices.

8. Synthesis

Overview: Synthesis offers high-quality speech synthesis, particularly suited for dynamic content creation and real-time applications. It provides flexible integration options and realistic voice output.

Pros:

• Realistic voice synthesis

• Flexible integration

• High-quality output

Cons:

• May lack some enterprise-level features

• Limited advanced customization

Common Use Cases:

• Dynamic content creation

• Real-time applications

• Interactive media

Pricing: The Starter Plan starts at $29/month, includes basic features and voices or upgrade to a Professional Plan for $59/month, includes advanced features and more voices.

9. Google Cloud Text-to-Speech

Overview: Google Cloud Text-to-Speech leverages cutting-edge AI to offer a wide range of voices and languages, making it suitable for virtual assistants, accessibility tools, and content creation.

Pros:

• Cutting-edge AI technology

• Extensive language and voice options

• Customizable voices

Cons:

• Privacy concerns

• Potential cost implications

• Lower voice quality when it comes to naturalness

Common Use Cases:

• Virtual assistants

• Accessibility tools

• Content creation

Pricing: Google offers $4 per million characters for standard voices or $16 per million characters for WaveNet voices.

10. Amazon Polly

Overview: Amazon Polly is part of the AWS ecosystem, offering seamless integration and scalability. It’s a reliable choice for customer service automation, e-learning, and media applications.

Pros:

• Seamless AWS integration

• Highly scalable

• Cost-effective pricing

• Extensive language support

Cons:

• Complex setup

• Lower voice quality and naturalness 

• Learning curve for new users

Common Use Cases:

• Customer service automation

• E-learning platforms

• Media applications

Pricing: AWS offers $4 per million characters for standard voices or $16 per million characters for neural voices.

What are the top text to speech use cases?

When it comes to text-to-speech, there are endless applications. Several of the most common use cases for text-to-speech include accessibility applications for visually impaired users, voice assistants and chatbots, e-learning platforms, audiobook production, navigation systems, and interactive voice response (IVR) systems. Text-to-speech is also widely used in content creation—such as generating voiceovers for videos or podcasts—and in the development of smart home devices and IoT applications.

Here’s a breakdown of several common applications for text-to-speech:

• Accessibility – Convert written content into speech, making emails, articles, websites, and other content more accessible 

• AI Voice Agents – Support customer inquiries and provide information with automated voice agents, improving efficiency and providing customer service 24/7

• Interactive Voice Response (IVR) Systems – Improve customer experience and operational efficiency by managing high call volumes, routing calls, and providing information

• E-learning – Improve comprehension by incorporating audio support into learning

• Healthcare – Streamline interactions between patients and care providers, enhancing care delivery

• Media and Podcasts – Increase engagement and improve user experiences with AI-generated voice overs for video games, presentations, podcasts and advertisements

Note: Some use cases require high-production value over high-throughput. Meanwhile, other use-cases prioritize throughput over production. For example, if you’re building a video game and need its characters to have clever-cut, actor-like voices, you’ll want to prioritize production over throughput. That’s what companies like ElevenLabs optimize for. 

Meanwhile, if you’re running a call center and require a large volume of text-to-speech API requests in real-time, you might want to sacrifice production value in favor of minimal latency. Real-life use cases—from drive-thrus, to hotel help-desks, to call-center handling—are what companies like Deepgram optimize for.

(If you’d like to learn about the most stand-out and popular use cases of TTS in entertainment and media, check out this article, or explore how TTS is revolutionizing call centers.)

How do you implement a text-to-speech API?

To implement a text to speech API, developers typically need to obtain API credentials from a chosen provider, integrate the API into their application using the provided SDK or REST endpoints, and send requests with the desired text and voice parameters. The API then returns the synthesized audio, which can be played back or saved as a file. Most TTS APIs offer documentation and code samples to guide developers through the implementation process.

Note: Text-to-Speech is different from voice cloning, which you may have seen in viral examples like this one (linked above). However, voice cloning is merely a subsection of TTS. To learn more about voice cloning, check out this article.

What are the most important things to consider when choosing a text-to-speech API?

When choosing a text-to-speech API, important considerations include the quality and naturalness of the synthesized voices, language and accent coverage, customization options, pricing models, integration ease, and scalability. It's also crucial to evaluate the APIs performance in terms of latency and reliability, as well as its compliance with relevant accessibility standards and data privacy regulations.

• Voice Quality: How natural and human-like the synthesized voices sound.

• Pro-tip: Test out Aura’s various unique voices here with our free AI Voice Generator tool

• Customization Options: Ability to adjust pitch, speed, and tone.

• Latency: The time it takes for the API to process the text and return the synthesized speech. Lower latency is crucial for real-time applications like conversational AI and live streaming.

• Integration and Scalability: Ease of integrating the API with existing systems and scaling as needed.

• Cost: Pricing models and overall cost-effectiveness.

• Support and Documentation: Quality of customer support and availability of comprehensive documentation.

High production use cases focus on high-quality, natural sounding voices for content creation, voiceovers, and media production. If you’re looking for an API to support these use cases, voice quality, customization options, and cost are all important considerations.

In contrast, high throughput applications put an emphasis on real-time, scalability for applications like customer support, conversational AI, and AI agents. When selecting APIs, you should consider response time, latency, integration ease, scalability, and cost.

Conclusion

Choosing the right text-to-speech API depends on your specific needs and use case. By understanding the pros and cons of each provider, and evaluating them against your requirements, you select the best solution to enhance your applications with natural-sounding, high-quality voice synthesis.

If you want to try Deepgram Aura, you can sign up for a free API key and build with $200 in free credit, good for up to 13,000 characters of voice synthesis. If you have more questions around how you can leverage Deepgram for your voice generation needs, feel free to contact our team of experts. Happy evaluating!