Best text to speech APIs in 2024

From natural-sounding speech synthesis to multilingual capabilities, these APIs redefine the way we interact with digital content. 

Whether you're developing educational software, customer service bots, or innovative apps, this list provides valuable insights into selecting the right TTS API to meet your specific needs and take your projects to the next level.

Summary

ElevenLabs

To use ElevenLabs' API, you first need to sign up for an API key on the website. Then, you can make a basic request by sending a POST request to their endpoint with your API key and the desired text. The API returns audio data in the form of an ArrayBuffer, which can be converted into an MP3 blob file for playback or saving​​​​.

ElevenLabs features

• Speech Synthesis
• VoiceLab Digital Cloning
• Voice Library
• Lifelike Speech Synthesis
• High-Quality Pre-made Voices

What’s missing?

• Limited control over the "last mile" of speech, like pacing, pauses, tone inflection​​.

AWS: Amazon Polly

Amazon Polly's API operations allow for synthesizing high-quality speech from plain text and Speech Synthesis Markup Language (SSML)​​. It provides options for customizing and controlling speech output, supporting lexicons and SSML tags​​.

Amazon Polly can be used to add speech to applications with a global audience, like RSS feeds, websites, or videos​​.

Amazon Polly features

• High-Quality, Natural-Sounding Voices
• Deep Learning Technology
• Global Audience Reach
• Interactive Voice Response Systems
• Customization with SSML Tags

What’s missing?

• Hard to customise unless you understand SSML for advanced customization.
• Its dependency on AWS infrastructure limits integrations with non-AWS services.

Amazon Polly sample demo

Descript

Descript's API enables audio generation and editing, with a focus on Overdub, a feature that generates audio using selected voice IDs. Users can create audio tasks and fetch results quickly. The API also supports editing, allowing the transfer of audio or video to Descript via Import URLs. 

Export features include various file formats, Descript link sharing, and cloud export for publishing. It ensures metadata consistency for projects edited in Descript and returned to partners. For security and efficiency, the API uses personal tokens and imposes rate limits like 500 overdubs per minute.

Note that only Descript Enterprise customers can use the Overdub API. 

​​Descript features

• AI-Powered Realism
• Effortless Audio Creation
• Diverse Vocal Styles
• Podcast Production
• Integrated Script Writing
• Voiceover Simplification
• Content Updating

What’s missing?

• Some users report inaccuracies in automated transcription.
• Despite an intuitive interface, mastering all features can be challenging.
• Available only on desktop for Mac and Windows, limiting on-the-go editing.
• Fewer options for exporting files in specific formats.
• Email-based support might not suffice for immediate assistance needs.
• Supports only 23 languages, which may not cover all user needs​​.

Descript sample demo

Google Cloud 

The Google Cloud Text-to-Speech API leverages advanced neural networks to convert text into human-like speech. This capability is particularly advantageous for creating interactive voice response systems and enhancing user experiences.

It offers customizable options like pitch, speaking rate, and volume gain, and integrates seamlessly with other Google Cloud services, such as Dialogflow and Translations API​​.

Google Cloud features

• Custom Voice Creation
• Extensive Voice Selection
• Multilingual Support
• Advanced Neural Network Technology
• Versatile Speech Customization

What’s missing?

• Requires a substantial database and coding for deployment.
• Lacks the ability to download converted voices as files.
• Offers fewer voice options for regional languages.
• Certain voice configurations may not have optimal accent quality​​.

Google Cloud sample demo

IBM Watson

IBM Watson's text to speech service supports a synchronous HTTP REST interface and a WebSocket interface for speech synthesis, accepting both plain text and SSML input.

SSML is an XML-based markup language for text annotation in speech-synthesis applications. The service also features customization options for sounds-like or phonetic translations, and a Tune by Example feature for defining custom prompts and speaker models.

IBM Watson text-to-speech features

• Customizable Built-in Tools
• Integration with Watson Assistant
• Multilingual Capabilities
• Wide Format Compatibility
• Real-Time Diagnostics.
• Speaker Diarization
• Reliable Algorithms
• AI-Based Features
• Comprehensive Customer Service
• Service Level Uptime Agreement (SLA)
• Accuracy

What’s missing?

• Sometimes mispronounces words
• Lacks sentiment analysis
• Accuracy needs improvement
• API can be complex to understand
• Processing time could be faster 

IBM Watson sample demo

Lovo

Lovo's APIs convert written text into realistic speech. The process involves analyzing linguistic patterns to produce natural-sounding voices. Users simply type in the text and generate the audio, facilitated by the sophisticated technology behind Lovo​​.

Lovo text-to-speech features

• AI Voice Cloning and AI Voiceover
• Natural-Sounding Voices in Various Languages
• Versatility for Multiple Use Cases
• Real-Time Voice Creation
• Background Music Integration
• Commercial Rights
• AI Voice Generation
• Text-to-Speech Conversion
• Extensive Voice Library
• Multiple Speakers
• Customization Options
• Document and SRT Upload

What’s missing?

• Voice cloning is limited to English.
• Requires an environment free from background noise for voice cloning.
• Limited integrations​​.

Lovo Sample Demo

Microsoft Azure

Microsoft Azure's Text to Speech API, part of its Cognitive Services, is designed to convert text into synthesized speech. It converts text into synthesized speech using a REST API and supports neural text to speech voices.

The API utilizes endpoints like tts.speech.microsoft.com for listing voices and cognitiveservices/v1 for converting text to speech. It also uses POST requests with SSML or plain text, and successful responses return an audio file in the requested format.

Microsoft Azure’s API requires authorization headers (Ocp-Apim-Subscription-Key or Authorization: Bearer) for access, with tokens valid for 10 minutes​​​​.

Microsoft Azure text to speech features

• Neural Text to Speech Engine
• Text to Speech Avatar
• Personal Neural Voice
• New Voice Styles and Emotions
• Comprehensive Speech Services Platform

What’s missing?

• Requires complex setup and training
• Inaccurate speech recognition
• Azure's text-to-speech service is expensive.
• Offers limited language and dialect support
• Challenges with large data handling and reporting
• Small developer community

Microsoft Azure sample demo

Murf.ai

The Murf.ai text-to-speech API converts written text into spoken words using digital signal processing algorithms. This integration is simple and secure, fitting seamlessly into existing technology stacks.

Key functionalities include real-time text-to-speech conversion, a wide variety of voices, support for multiple languages and dialects, and the ability to output in various audio formats like MP3, FLAC, and WAV​​.

Murf.ai text to speech features

• Natural Sounding Voices
• Simple and User-Friendly Interface
• Collaboration Tools
• Import and Export Files and Media
• Multilingual Support
• Customization Features
• Professional Speech Quality
• Voice Cloning

What’s missing?

• Limited customization options
• Potential lack of privacy and security 
• Could be expensive for high-volume needs

MurfAI sample demo

Play.ht

The API allows access to AI Voices from various providers including PlayHT, Google, Amazon, IBM, and Microsoft through a single interface. This unified approach saves time and simplifies maintenance since you only need one integration.

PlayHT's Turbo voice models can generate speech in less than 300ms, and the API automatically updates to include all improvements made by the TTS providers, ensuring access to the latest voices​​​​.

Users can access a growing library of 829 high-quality voices in different languages and can manipulate voice tones, including volume, rate, and pitch, for unique voice effects.

The API also supports text and Speech Synthesis Markup Language (SSML), allowing for advanced pronunciation instructions and other effects​​.

Play.ht features

• 800+ AI Voices
• Supports 140+ Languages
• Expressive Speech Styles
• Voice Cloning.
• Custom Pauses
• Custom Pronunciations
• Conversational TTS
• Unlimited Downloads
• Integrations with WordPress and Zapier

What’s missing? 

• Limited voice selection for non-English languages
• Restrictions in the free plan
• Potentially prohibitive costs for extensive TTS conversion

Play.ht sample demo

Resemble AI

Resemble.AI’s API enables the rapid creation and integration of custom AI voices using modern tools. It allows for fetching existing content, creating new clips, and building voices on-the-fly.

This functionality is vital for producing content in sync with low latency, making it ideal for real-time applications.

Developers can use the API to programmatically control voices, either through the API itself or within the Unity engine. This flexibility is particularly beneficial for creating unique character voices in video games and other interactive media.

The API offers a one-click upload functionality, allowing users to clone speech from any given audio. This feature is useful for those who have existing audio from voice talents and wish to bring these voices onto the Resemble AI platform.

However, it's important to note that valid consent from the voice talent must be provided for the audio files uploaded​.

Resemble AI features

• Voice Cloning
• Neural Audio Editing
• Mobile Support
• API Integration
• Emotions
• Deepfake Detection
• Development Tools
• GPT, Twilio and Dialogflow Integrations

What’s missing?

• Requires some technical expertise.
• Synthetic voices may lack some nuances compared to human voice actors.
• Limited language support (up to 62 languages).
• No free version available.

Resemble AI sample demo

Understanding text to speech technology

Text to Speech (TTS) technology converts written text into spoken words, using artificial intelligence and natural language processing. It enables applications to read out text, enhancing user engagement and accessibility.

This technology has evolved significantly, offering more natural and human-like voices. Understanding its underlying mechanisms, such as speech synthesis and voice modulation, is key for developers looking to integrate TTS in their applications.

The benefits of integrating TTS in your applications

Integrating TTS APIs into applications offers numerous benefits. It improves accessibility for users with visual impairments or reading difficulties, expands reach to non-readers, and enhances multitasking capabilities.

TTS also supports diverse language needs, making content universally accessible. By providing auditory content, TTS APIs facilitate better user engagement and can significantly enhance the user experience in various applications, including e-learning, navigation, and customer service.

The different pricing models for TTS APIs

Pricing models for TTS APIs vary widely. Some offer free tiers with basic features, ideal for small-scale projects or experimentation.

Subscription-based models, on the other hand, typically provide more advanced features and higher usage limits, catering to larger businesses.

Pay-as-you-go options allow for flexibility and are cost-effective for fluctuating usage. When selecting a TTS API, consider factors like the scale of your project, required features, and budget constraints to choose the most suitable pricing model.

Final thoughts

Text to Speech (TTS) APIs convert written text into spoken words, leveraging artificial intelligence to produce natural-sounding speech.

These tools are vital for enhancing accessibility, supporting multilingual communication, and improving user engagement across various applications. 

TTS APIs are especially beneficial for those with visual impairments or reading difficulties. When selecting a TTS API, consider the quality of speech synthesis, language and customization options, integration ease, pricing models, and security measures.

These factors ensure the API meets specific project needs while providing a seamless and inclusive user experience.

About ElevenLabs

ElevenLabs stands at the forefront of AI voice generation technology. We offer a selection of 120 unique voices in 29 languages.

What’s more, our tool's intuitive interface lets you fine-tune your audio, whether you're producing an audiobook or adding flair to video game narration. Trusted by digital creators worldwide, Eleven Labs sets the standard for lifelike, versatile, and secure AI-generated speech.