11+ Best Text to Speech APIs [2024]

In today's digital landscape, text-to-speech (TTS) technology has become increasingly important for creating engaging audio content. Text-to-speech APIs allow developers to integrate speech synthesis capabilities into their applications, enabling the conversion of written text into natural-sounding audio or video. 

TTS APIs offer a wide range of voices, languages, and customization options to suit various use cases, from e-learning and accessibility to voice assistants and customer service to sales and personalized marketing. 

As the demand for voice-enabled applications grows, choosing the right TTS API is crucial for delivering high-quality, lifelike speech outputs–without having to develop one yourself. 

In this article, we'll explore the best text-to-speech APIs available, including their key features, ideal use cases, and more.

What is a text-to-speech API? 

A text-to-speech (TTS) API is a set of protocols, routines, and tools that allows developers to integrate speech synthesis capabilities into their applications or websites. These APIs convert written text into audible speech, enabling machines to read out text in a natural, human-like voice.

TTS APIs use advanced algorithms and machine learning techniques to analyze and process text, break it down into phonemes (the smallest units of sound in a language), and generate corresponding audio output. 

They offer a variety of voices, languages, and customization options to create lifelike speech that closely resembles human speech patterns, intonation, and pronunciation.

Here are the most common use cases:

• Accessibility for visually impaired users
• Interactive e-learning and training materials
• Voice output for virtual assistants and chatbots
• Automated creation of audiobooks and podcasts
• Video marketing
• Voice-based navigation and information in automotive systems

Best Online Text-to-Speech APIs

Here are some of the best TTS APIs on the market today:

1. Tavus API

Developers can use Tavus to enable their users to access a cutting-edge AI-powered platform that offers advanced text-to-speech capabilities for creating personalized, engaging video content. With its state-of-the-art voice cloning technology, Tavus enables users to generate human-like voice overs that closely match the style, tone, and emotion of a chosen speaker.‍

What makes Tavus number one on the list is that it combines TTS API with an AI video generator. Developers can allow users to adjust variables such as names, dates, and product information, which Tavus then seamlessly integrates into the video content using its sophisticated AI algorithms. This level of personalization helps users connect with their audience on a deeper level, leading to increased engagement and conversion rates.

Key features: 

• Advanced AI voice cloning for natural, human-like speech output
• High-definition, realistic lip-syncing for lifelike video avatars
• Lip Sync and Dubbing APIs 
• Dub videos in over 30 foreign languages, matching their voice and lip movements
• Creates realistic avatars that mimic facial expressions and lip movements for lifelike interactions
• Automate and scale video production without manual intervention

‍Using the Tavus API, developers can access AI video generation with unprecedented realism and customization, enabling a wide range of applications.‍Experience the Tavus API today.

2. Google Cloud Text-to-Speech API

Google Cloud Text-to-Speech API enables developers to convert written text into natural-sounding speech using Google's AI technologies. The API offers selection of voices and languages, along with customization options to tailor the speech output to specific needs. 

Users can access Neural2 voices or create unique voice models using their own audio recordings. The API  allows for voice tuning, letting users adjust pitch and speaking rate to personalize the voice output.

Additionally, it supports SSML tags for customizing speech with pauses, numbers, dates, and pronunciation instructions.

Key features: 

• Neural2 voices powered by research in speech synthesis
• Studio voices (Preview) that are recorded in studio environments
• Custom Voice feature to train unique voice models using your own audio recordings

3. Microsoft Azure Text-to-Speech API

Microsoft Azure Text to Speech is an AI-powered service that converts text into speech so applications can speak naturally. The platform offers customizable voice generation with various speaking styles and emotional tones to suit different use cases, from text readers and talkers to customer support chatbots. ‍

Azure Text to Speech provides fine-grained control over voice output, allowing users to adjust rate, pitch, pronunciation, pauses, and intonation using Speech Synthesis Markup Language (SSML) or the audio content creation tool. The service can be deployed in the cloud, on-premises, or at the edge using containers.

Key features: 

• Lifelike synthesized speech that matches the intonation and emotion of human voices
• Customizable text-talker voices to reflect a brand's identity
• Fine-grained audio controls to tune voice output for specific scenarios

4. Amazon Polly 

Amazon Polly is a text-to-speech service that uses deep learning technologies to synthesize natural-sounding human speech. With dozens of voices across a broad set of languages, Amazon Polly enables developers to build speech-activated applications, convert articles to speech, and deliver natural-sounding voice experiences. ‍

The service allows for customization and control of speech output using lexicons and SSML tags and supports storing and redistributing speech in standard formats like MP3 and OGG. Amazon Polly delivers consistently fast response times, making it suitable for various use cases such as content creation, e-learning, and telephony.

Key features: 

• Deep learning technologies to synthesize natural-sounding human speech
• Dozens of lifelike voices across a wide range of languages
• Ability to store and redistribute speech in standard formats (MP3, OGG)

5. Descript 

Descript is a text-to-speech platform that utilizes AI to generate realistic audio from typed text. The service offers a range of natural-sounding stock voices, as well as the ability to create custom AI voice clones. Descript's AI voice model has been trained on real human speech patterns. The platform also allows for the creation of multiple voice clones to suit different recording conditions, emotions, or content tones.

Key features: 

• Natural-sounding AI voices trained on real human speech patterns
• Ability to create custom AI voice clones for a personalized touch
• Stock voices with various vocal styles to match different settings, emotions, and lifestyles

6. ElevenLabs

ElevenLabs offers a text-to-speech platform that leverages artificial intelligence to produce speech that closely mimics human voices. This technology provides a wide selection of voices and languages aimed at various applications such as audiobooks, virtual assistants, and multimedia content creation.

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Key features: 

• Advanced AI for realistic voice synthesis
• Wide range of languages and voices for diverse applications
• Ease of integration with existing applications and systems

7. IBM Watson Text-to-Speech

IBM Watson Text to Speech converts written text into natural-sounding audio in multiple languages. Utilizing IBM's artificial intelligence, it offers expressive and nuanced speech output. This service is designed for creating voice-enabled applications, and enhancing user experiences on the web and mobile interfaces. It supports control over speech characteristics through SSML, allowing for a tailored audio output.

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Key features: 

• High-quality, natural-sounding speech synthesis in multiple languages
• Control over speech characteristics for tailored audio outputs
• Versatility in use cases, from web applications to interactive learning

6. Lovo

Lovo provides a text-to-speech service with a focus on natural and dynamic voice creation. It offers over 500 voices across 100 languages, catering to a wide array of content creation needs. Lovo's platform is particularly geared towards content creators, marketers, and educators seeking to produce engaging audio content.

Key features: 

• Voice library in multiple languages
• Voice cloning technology for creating unique voice skins
• Supports natural voices and language

7. MurfAI

MurfAI is a text-to-speech platform that provides a selection of voices for professional-grade audio output. It’s designed for use in presentations, educational content, video production, and more. The platform offers features such as voice customization and audio editing.

Key features: 

• Selection of lifelike voices for professional audio
• Easy integration and customization for efficient content creation
• Audio editing tools for precise project alignment

8. OpenAI API for Text-to-Speech

The OpenAI API for Text-to-Speech employs advanced AI models to produce customizable and natural-sounding speech. It supports a wide range of languages and dialects, making it suitable for a diverse set of applications, including educational software and interactive storytelling. The API is designed for developers looking to integrate TTS into applications and platforms.

‍Key features: 

• Advanced AI models for high-quality voice generation
• Support for multiple languages and dialects
• Flexible integration options for developers

11. Speechify 

Speechify is a text-to-speech application aimed at improving accessibility and convenience. It transforms text from books, documents, and web content into spoken word, catering to individuals with reading disabilities or preferences for auditory learning. Speechify offers options to customize voice type, speed, and other parameters.

Key features: 

• Customizable listening experience with various voice and speed settings
• Compatibility with multiple text formats and sources
• Focus on accessibility and convenience for users with reading challenges

Use Cases for TTS APIs

Some common use cases include:

• AI Video Generation: Generates exceptionally realistic talking head videos, complete with natural face movements and expressions accurately synchronized with input.
• E-learning and training: TTS APIs can be used to create engaging, interactive educational content and training materials, allowing learners to absorb information through audio.
• Voice assistants and chatbots: TTS technology powers the speech output of virtual assistants like Siri, Alexa, and Google Assistant, as well as chatbots, facilitating more natural and engaging user interactions.
• Audiobooks and podcasts: Text-to-speech APIs can streamline the production of audiobooks and podcasts by automating the process of converting written content into spoken audio.
• Automotive and navigation systems: TTS is used in GPS navigation systems and in-car infotainment systems to provide voice-based directions and information to drivers, enhancing safety and convenience.
• Telecommunications: TTS technology can be utilized in interactive voice response (IVR) systems, enabling automated customer support and reducing the need for human operators.
• Accessibility: Text-to-speech technology enables visually impaired individuals to access written content by converting it into spoken words, making websites, applications, and documents more inclusive.
• Healthcare: TTS APIs can assist in creating accessible medical information, such as prescription instructions, and can be used in medical devices to provide verbal guidance to patients.
• Media and entertainment: TTS can be employed to create voice overs for videos, animations, and games, saving time and resources in the production process.

More Questions On Text-to-Speech APIs

As the demand for voice-enabled applications and services grows, many developers and businesses have questions about text-to-speech APIs. Here are some common questions and their answers:

What's the best text-to-speech API?

The best text-to-speech API depends on your specific needs and requirements. However, Tavus stands out as a top choice due to its advanced AI voice cloning capabilities, personalization features, and ability to create lifelike video avatars with realistic lip-syncing.

Does OpenAI have a text-to-speech API?

Yes, OpenAI offers a text-to-speech API as part of its suite of AI tools. The API leverages OpenAI's advanced language models to generate natural-sounding speech from input text.

How do I enable text-to-speech API?

To enable a text-to-speech API, you typically need to sign up for an account with the API provider, obtain an API key, and then integrate the API into your application using the provider's documentation and code samples. The specific steps may vary depending on the API provider and your development environment.

Is Google text-to-speech API free?

Google Cloud Text-to-Speech API offers limited free usage and provides new customers with $300 in free credits. As of March 2024, Google provides 4 million characters per month free for Standard (non-WaveNet) voices and 1 million characters per month free for WaveNet voices. Beyond these limits and the initial free credit, you'll be charged based on the number of characters processed.

Use the Best Online Text-to-Speech APIs

Text-to-speech technology has revolutionized the way we interact with digital content, making it more accessible, engaging, and personalized. With the rise of AI-powered TTS APIs, developers, and businesses now have access to a wide range of powerful tools to create lifelike, natural-sounding speech output.

Among the various text-to-speech APIs available, Tavus remains the top choice for developers seeking to deploy advanced AI voice cloning, hyper-personalization, and the ability to create realistic video avatars directly into their platforms. 

Tavus' unique blend of voice cloning, video avatar creation, and hyper-personalization makes it an ideal solution for teams looking to offer truly immersive and tailored voice experiences for their users.

‍Experience Tavus today