Deploy high-quality, natural-sounding human voices in dozens of languages.
Grade: A — Score: 93/100
Amazon Polly utilizes advanced deep learning technologies to convert text from various sources, including articles and documents, into lifelike speech. The service supports a wide range of languages and voices, allowing developers to create engaging speech-enabled applications that cater to diverse user needs.
The integration process is streamlined through a simple API, enabling applications to quickly become voice-ready. Users can customize speech output using SSML and lexicons, ensuring that the generated audio aligns with specific requirements and enhances user experience.
While Amazon Polly offers robust features and capabilities, users must be mindful of potential risks such as dependency on cloud services and data privacy considerations. AWS prioritizes security and does not retain content from text submissions, but users should still implement best practices for data management.
Standard Engine: $4.00 per 1 million characters
Neural Engine: $16.00 per 1 million characters
Generative Engine: $30.00 per 1 million characters
Long-Form Engine: $100.00 per 1 million characters
Consider switching to Google Text-to-Speech: Google offers competitive pricing and a wide range of voices and languages.
Amazon Polly and Google Cloud TTS are priced similarly at $16.00 per 1 million characters for their neural-quality voices. Polly differentiates with four distinct voice engines (Standard, Neural, Generative, and Long-Form) at different price points, per-word Speech Marks metadata for lip-sync and animation, and a Bidirectional Streaming API on its Generative engine. Google Cloud TTS offers self-service voice cloning and a free tier that continues indefinitely past 12 months, while Polly's free tier expires after 12 months. Polly is the natural choice for teams already on AWS, while Google Cloud TTS fits better in a Google Cloud ecosystem.
ElevenLabs offers higher emotional expressiveness, instant voice cloning from a short audio sample, and over 5,000 voices, making it stronger for audiobook narration and creative content. Amazon Polly focuses on developer infrastructure: it provides four voice engines (including a $4.00 per 1 million characters Standard tier for high-volume batch work), SSML-based pitch/rate/volume control, Speech Marks for animation synchronization, and native integration with AWS services like Amazon Connect. Polly is significantly cheaper — its Neural engine costs $16.00 per 1 million characters versus ElevenLabs' approximately $165 per million — making it the better fit for cost-sensitive, high-volume applications like IVR systems and automated notifications.
Standard ($4.00/1M characters) uses concatenative synthesis and is the cheapest option for high-volume batch processing. Neural ($16.00/1M characters) uses a sequence-to-sequence model for significantly more natural speech and supports the Newscaster speaking style. Generative ($30.00/1M characters) is Polly's flagship engine, using a billion-parameter transformer for the most human-like, emotionally engaged speech with Bidirectional Streaming API support. Long-Form ($100.00/1M characters) is purpose-built for extended narration like audiobooks and training videos, with only 6 available voices (Danielle, Gregory, Ruth, Patrick, Alba, and Raul).
Yes, Amazon Polly can generate audiobook-quality speech using its Long-Form engine ($100.00 per 1 million characters) or its Generative engine ($30.00 per 1 million characters). The Long-Form engine is specifically designed to maintain listener engagement over extended content. However, individual API requests have a character limit, so longer texts need to be broken into segments and stitched together (the asynchronous StartSpeechSynthesisTask API supports up to 100,000 billed characters per request). Note that some distribution platforms like ACX do not accept AI-generated narration, so check your intended platform's policies before producing a full audiobook.
Amazon Polly does not offer self-service voice cloning. Its Brand Voice program allows organizations to create an exclusive Neural TTS voice, but this is a custom engagement where you work directly with the Polly team — it involves identifying a persona, recording a professional voice actor, and training a model. National Australia Bank and Bank of New Zealand are published Brand Voice customers. For teams that need instant voice cloning from a short audio sample, alternatives like ElevenLabs or Azure AI Speech's Custom Neural Voice offer self-service options, though at higher per-character costs.
By default, yes. AWS may use content processed by Amazon Polly to improve the service and develop other machine-learning technologies, and may store that content in a region outside your selected AWS region. However, you can opt out via an AWS Organizations opt-out policy — when you do, AWS deletes all previously stored historical content associated with your account. Amazon Polly states it does not retain the content of text submissions for service delivery purposes, and all content is encrypted at rest and in transit. Output audio belongs to the user.
The real-time SynthesizeSpeech API has a default quota of 80 transactions per second for Standard voices in a single region, with the same value serving as the concurrent request limit. Individual SynthesizeSpeech requests are capped at 3,000 characters of input text (6,000 total including SSML tags). The asynchronous StartSpeechSynthesisTask API supports up to 100,000 billed characters per request. You can store up to 100 custom pronunciation lexicons per account. Quota increases can be requested through the AWS Support Center for high-volume production workloads.
Amazon Polly is natively integrated with Amazon Connect, AWS's cloud contact center service, allowing dynamic text-to-speech prompts in IVR flows without additional configuration. It also integrates with the Amazon Chime SDK for real-time communications and is supported by third-party contact center platforms including Genesys Cloud CX and several AWS Contact Center Intelligence (CCI) partners like Vonage and Accenture. The Generative engine's Bidirectional Streaming API enables real-time conversational voice responses, making Polly suitable for dynamic agent-assist and virtual agent scenarios.