Key takeaways:
- Text-to-speech (TTS) APIs convert text into audio using natural language processing and voice synthesis to improve accessibility and user experience.
- When choosing a TTS API, consider voice quality, language support, customization options, integration ease, pricing, and scalability.
- Tavus API incorporates TTS technology to create natural-sounding voiceovers, enabling app users to create personalized video content at scale.
Text-to-speech (TTS) AI technology has a wide range of applications, from accessibility tools and voice assistants to e-learning platforms and content creation. By converting written text into natural-sounding spoken words, TTS AI enables devices to communicate with users in a more human-like manner.
With a growing number of TTS AI APIs available, it's crucial to thoroughly evaluate each option to choose the right one for your app or project. These APIs vary in terms of voice quality, language support, customization options, and pricing. In this guide, we’ll dive into the best text to speech AI APIs, exploring their unique features, pricing structures, and voice fidelity to help you find the best fit for your needs.
What are Text-to-Speech AI APIs?
TTS APIs are software interfaces that enable the integration of text-to-speech functionality into apps, websites, or devices. These APIs take written input and convert it into audio output, allowing apps to "speak" text and provide a more interactive experience for users.
These interfaces use natural language processing (NLP) and voice synthesis technologies. Here’s a quick overview of the process:
- Analyze text: The API parses the user’s text input to identify words, punctuation, and structure.
- Linguistic modeling: The API uses NLP algorithms to determine pronunciation, intonation, and emphasis, considering language rules and context.
- Speech synthesis: The system converts text into audio using pre-recorded voice samples or AI-generated voices.
TTS APIs enhance your app's user-friendliness and accessibility. For example, users with visual impairments may have difficulty navigating your app without TTS, potentially leading them to abandon it altogether. By integrating TTS, you allow users to interact with your app effortlessly in their preferred language, creating a more inclusive and engaging experience.
How to Choose the Best Text-to-Speech AI API
Here’s what you should consider when choosing a TTS API:
- Voice quality: This is the heart of any TTS API. The API should be able to generate speech that sounds natural and not like that robotic monotone from the early 2000s. APIs that use neural text-to-speech (NTTS) technology are ideal because they can replicate human-like intonation, emotion, and pacing.
- Language and dialect support: If your target audience includes people in non-English-speaking countries, you need an API that supports multiple regional dialects. It should also be able to distinguish between accents.
- Customization options: Can you tweak the voice to fit your founder’s or brand’s personality? Voice APIs with customization pitch, speed, and tone can help you create unique voices tailored to your use case.
- Integrations: No developer wants to jump through hoops to integrate an API. Before you settle on an API, look for detailed documentation, SDKs, and support for popular programming languages.
- Pricing: TTS APIs often have tiered pricing models. Evaluate costs for key metrics like characters processed, audio length, or API calls. Also, factor in the costs of scaling the API’s use in the future.
- Scalability: Can the API scale with your business without breaking the bank—or your app? Look for an API that supports high-volume usage. The best tools support millions of daily interactions and real-time processing across multiple users.
Best Text-to-Speech AI APIs and Platforms
To help narrow down your choice, we’ve compiled a list of the top TTS APIs and platforms. We explain their strengths and weaknesses and who they might be suitable for below.
1. Tavus API
Tavus API incorporates advanced TTS technology to create lifelike voiceovers. Powered by cutting-edge AI, it goes beyond traditional voice synthesis, allowing users to seamlessly add voiceovers to videos through your app and quickly generate high-quality output.
Tavus combines sophisticated neural network models with proprietary algorithms to ensure voice outputs sound remarkably natural, with authentic annotation, rhythm, and emotion. The platform is highly customizable, enabling you to adjust parameters such as pitch, speed, and tone to create personalized voiceovers and deliver tailored messages to individual users.
Tavus' API is designed for easy integration into various environments. Its scalable architecture supports businesses of all sizes—from startups to large enterprises—and ensures smooth performance even during high-demand periods. Tavus provides comprehensive API documentation, including detailed guides and references, to help you fully leverage its features.
Features:
- High-quality voiceover content
- AI voice cloning
- 30+ languages
- Highly customizable
If you’re looking to add TTS capabilities into your app to allow users to create lifelike voiceovers, try Tavus today.
2. Amazon Polly
Amazon Polly is popular for its high-quality voice synthesis and extensive language support. It can be used for various applications, including voice assistance, e-learning, audiobooks, and accessibility tools.
The platform offers various features, such as:
- Speech Marking, which provides metadata for speech elements like words, sentences, or phoneme timings
- SSML (Speech Synthesis Markup Language), which helps fine-tune aspects like pronunciation, volume, speed, and pitch for customized output
Polly does have a few drawbacks. For example, the pricing model is based on characters synthesized, which makes it a costly choice for projects with high usage. While Polly’s voices are highly realistic, you may find them less customizable than those from providers that also focus on personalization.
Features:
- Broad language and voice support
- SSML support
- Speech marks and metadata
- Supports various audio formats, including MP3, OGG, and PCM
3. Google Cloud Text-to-Speech
Google Cloud TTS uses DeepMind’s WaveNet technology to generate human-like voices. It offers SSML to control pitch, speed, and emphasis, which allows you to customize for unique applications. It also offers real-time audio streaming, making it useful for interaction solutions such as virtual assistants and chatbots.
However, the cost of neural voice synthesis can add up for high-volume projects. While Google supports a wide range of languages, it’s also important to be mindful of the lack of hyper-localized dialect options.
Features:
- Built based on DeepMind’s speech synthesis expertise
- 380+ voices and 50+ languages
- Text and SSML support
- Personalized communication based on user preference of voice and language
4. Microsoft Azure Text-to-Speech
Microsoft Azure TTS uses AI models to produce natural-sounding voices and supports over 140 voices across 70+ languages and dialects. It offers SSML support and integrates seamlessly with other Microsoft services, such as Cognitive Services and Power Automate.
This TTS platform is suitable for enterprise-level businesses that want flexibility, advanced customization, and integration within the Microsoft ecosystem. However, the extensive features do present a steep learning curve.
Features:
- Audio output customization
- Custom voice creation
- Extensive language and voice support
- SSML
5. IBM Watson Text to Speech
IBM Watson TTS combines AI technology with a simple interface. It supports multiple languages and accents as well as features like customizable voice synthesis and SSML.
However, IBM Watson offers fewer voice options compared to many of its competitors. Moreover, if you’re working with a limited budget, you’ll need to look elsewhere.
Features:
- Real-time speech synthesis
- Controllable speech attributes
- Customized word pronunciations
- Personalized voice quality
6. Murf.ai
Murf.ai helps generate natural-sounding voiceovers with little complexity. It offers a library of voices across multiple languages and built-in voice editing tools to adjust pitch, speed, and tone.
This platform is typically used to create audio content for videos, podcasts, and e-learning modules. However, it’s not as feature-rich as some other TTS platforms. If you’re a large enterprise, you might find its extensive API integration needs rather limiting.
Features:
- Natural-sounding voices
- 120+ AI voices across 20+ languages
- Import and export various file formats (DOCX, TXT, and SRT for scripts and MP3, FLAC, and WAV for audio)
- Library of royalty-free background music
7. ElevenLabs
ElevenLabs uses deep learning models to produce voices with nuanced emotions and natural intonation, which means it can be used for audiobooks, gaming, and storytelling applications. It has voice-cloning technology that replicates a user’s voice while also supporting multiple languages and accents.
However, since it's primarily geared toward creative and niche applications, it’s not the best large-scale enterprise solution. If you require broader language support or integration with enterprise workflows, you’ll need to look at other options. Check out our extensive ElevanLabs review if you’re looking for more information about ElevenLabs’ capabilities.
Features:
- Voice cloning
- Multilingual support
- Customizable speech parameters
- AI-driven context awareness
8. Descript Text-to-Speech
Descript TTS is designed specifically for creators who want to generate voiceovers. It offers voice cloning that helps create a personalized digital version of their voice. The AI-driven TTS engine produces natural-sounding speech. There’s also a voice-cloning feature that replicates the user’s voice without the need for re-recording.
However, some users have reported occasional inaccuracies in transcription, especially with unique names or accents. This requires manual correction.
Features:
- Voice cloning
- Integrates with Descript editor
- Text-to-voice editing
- Cross-platform accessibility (has desktop and web versions)
9. Lovo AI
Lovo AI offers a selection of over 500 voices across 100+ languages, enabling creators to engage global audiences. There’s a built-in feature called Genny, an all-in-one voice and video editing tool.
However, some of the synthetic voices sound more robotic than others. You’ll need to spend some time selecting a voice that suits your needs and sounds human-like.
Features:
- Extensive voice library
- Voice cloning
- Genny AI tool
- AI scriptwriting
10. Play.ht
Play.ht is a cloud-based AI voice generator and TTS platform. It offers a library of over 8,000 AI-generated voices supporting more than 142 languages and accents. The Play.ht Voice Generation API facilitates real-time voice cloning and generation and integration into various applications.
Play.ht charges per word. So, if you’re looking to convert long texts or books to speech, Play.ht may cost you a fair bit more than its alternatives.
Features:
- 1,000+ voices with 142+ languages and accents
- Contextual awareness
- High-quality, low-latency audio streaming
- AI voice library
11. Resemble AI
Resemble AI supports TTS as well as speech-to-speech functionalities. It offers multilingual support, allowing users to generate voiceovers in multiple languages and accents. The platform generates voiceovers with expressive synthetic speech.
Resemble AI is created for enterprise users. If you’re a small business or developer or have infrequent voice generation needs, Resemble AI might not be the best tool for you.
Features:
- Range of AI voices
- Custom AI voice cloning
- Natural voice modification
- API and integration
12. Speechify
Speechify turns various types of content, including web pages, PDFs, emails, and more, into audio. The platform supports over 30 languages and allows customizing playback speed, allowing users to listen at their preferred pace.
It’s important to remember that the free version offers limited features and might not suffice for power users.
Features:
- 200+ lifelike AI voices
- 50+ languages
- Scan and listen
- Customizable playback speed
13. Colossyan
Colossyan creates realistic AI-driven voiceovers. It also focuses on video production integrations, allowing users to add TTS voiceovers to video projects. Users can customize audio to match their specific needs by adjusting the pitch, tone, and speed.
The platform allows you to create voiceovers without any technical expertise. However, Colossyan’s focus on video integration might not be appealing if you’re looking for a TTS solution solely for standalone audio projects.
Features:
- Seamless video integration
- Customizable voice parameters
- Multilingual support
- Enhanced engagement features
14. ReadSpeaker
ReadSpeaker specializes in providing voice solutions to a variety of industries, including education, healthcare, and e-learning. It offers a range of AI-driven natural voices, available in over 35 languages. The platform offers TTS capabilities that can be integrated into apps, websites, and learning management solutions (LMS).
It’s not the best platform if you’re an individual user or small business because of potentially higher costs and complexity. Instead, choose a more user-friendly platform that’s tailored to a small business or casual user’s needs.
Features:
- Readspeaker’s API and SDKs allow Integration with apps and websites
- Offline and online deployment
- Accessibility features
- Multilingual support
15. OpenAI
OpenAI’s TTS API uses AI models to create highly realistic, human-like speech in multiple languages and accents. Users get control over voice parameters like on most other platforms. Moreover, OpenAI’s API integrates into various applications, so developers can embed speech capabilities into their services.
That said, OpenAI’s TTS is fairly new. Its customization options aren’t as extensive as more established platforms. If you need those, consider Tavus.
Features:
- Ability to adjust pitch, speed, and tone
- Multilingual support
- Easy integrations via API
- Supports most of the commonly used audio formats
Learn More About the Best Text-to-Speech APIs
Now that we’ve talked about the best text to speech AI APIs, let’s explore some common questions.
What sets Tavus apart from other TTS providers?
Tavus API offers a broader range of capabilities, with TTS built into its overall feature set. Here’s what you get:
- Human-like voice: Tavus API offers bespoke voice cloning that can generate voices with precise emotion and tonality. It offers minimal latency, which makes both video and audio outputs more authentic and lifelike.
- Extensive feature set: Tavus uses custom voice models to replicate unique speech patterns, tones, and emotional intonations. It also syncs voiceovers with video content and makes it easy to apply TTS customizations at scale for use cases like personalized marketing campaigns and customer support systems.
- Exceptional customer support: Our clear documentation and onboarding set developers up for success right off the bat. Moreover, there’s always our support team at Tavus to quickly respond to your messages and offer ongoing assistance for troubleshooting.
How can I integrate a TTS API into my application?
Here’s a quick overview of the process of integrating a TTS API into your application:
- Get API credentials from your TTS API provider: Once you sign up with a service provider, create an API key and store API credentials in a secure location. These credentials are used to authenticate API calls. Here’s an example:
{
"Authorization": "Bearer YOUR_API_KEY"
}
- Read documentation and install SDKs and libraries: The documentation includes API’s capabilities, endpoints, and integration steps. It will include examples of SDKs for different programming languages. SDKs and libraries provided by the API make integration easier.
- Make API calls: Start by including your API key or OAuth token in the request headers. Then, define parameters such as input text (that you want to synthesize into speech), voice selection (gender, tone, language, etc.), and output format (MP3, WAV, etc.). Combine these elements to make a request to the API endpoint. Here’s an example:
{
"text": "Hello, how can I help you today?"
"voice": {
"languageCode": "en-US",
"name": "en-US-Wavenet-D",
"ssmlGender": "MALE"
}
}
- Handle the output: Save the audio file into a directory or stream it directly in your app.
- Integrate into your workflow: Embed the TTS feature into your app based on your use case. This could be screen readers (for accessibility), personalized marketing, or automated customer service.
Are there any free TTS APIs available?
Yes, there are several free TTS APIs, such as:
- Tavus: Tavus offers a lot more than just TTS capabilities, and you can get free limited access to many of its features. The free plan includes three minutes of free credit for video generation and conversational video and 5 stock Replicas
- Google Cloud Text-to-Speech: 60 free minutes of TTS usage per month
- AWS Polly: One million characters per month free during the first 12 months
- DeepSpeech (Open Source): Entirely free, open-source option
It’s best to think of free tiers as a way to try the platform. Advanced features and higher usage limits needed for commercial use are typically only available with paid versions.
Can I use TTS APIs for commercial projects?
Yes, you can use the TTS API for commercial projects, but be sure to check licensing terms and limitations because they vary across different providers. Check if the service provider requires you to include proper attribution or adhere to any content guidelines when using their service commercially.
Choose the Best Text-to-Speech AI API for Your Needs
TTS APIs can transform text into natural-sounding speech, making them essential for creating interactive applications like virtual assistants, accessibility tools, and personalized content platforms. When selecting a TTS AI API, it’s important to consider voice quality, language options, latency, and ease of integration. Evaluating each provider's features ensures you choose the best fit for your app's specific needs.
Tavus is an industry leader, offering advanced AI video generation capabilities with seamless TTS and ASR functionalities. With Tavus, developers can empower app users to create dynamic video content featuring personalized voiceovers and build digital replicas that elevate user experiences. Tavus offers versatile tools that make it ideal for enhancing app accessibility, engagement, and innovation.
Committed to delivering exceptional support, Tavus ensures a smooth integration process and is always ready to assist with technical challenges.
Explore Tavus' advanced AI video API with text-to-speech capabilities and discover how it can transform your applications. Sign up for a free trial today!
