Amazon Polly is a powerful text-to-speech (TTS) service that helps developers create natural-sounding voice applications. Whether you're building an interactive assistant, an e-learning platform, or an audiobook service, Polly offers high-quality speech synthesis at scale. However, understanding its pricing model and finding ways to reduce costs can make a big difference in your budget.
In this guide, we’ll break down Amazon Polly’s pricing structure, explore key cost factors, and share practical tips to help you optimize expenses while making the most of its capabilities.
AWS text-to-speech pricing includes Standard, Neural, Long-Form, and Generative Voices, with Free Tier allowances for the first 12 months. AWS GovCloud (US) has slightly higher rates. The pricing structure helps users understand different voice types and their associated costs.
A digital publishing company in the US East (N. Virginia) region is converting its latest novel into an audiobook using Amazon Polly. The book contains 120,000 characters, and the company chooses Neural TTS for its natural and high-quality speech output.
Pricing Calculation:
Total Cost Calculation:
(120,000 ÷ 1,000,000) × $16 = $1.92
Alternative Pricing Options:
By analyzing these pricing models, publishers can choose the most cost-effective option based on their budget and desired audio quality.
To efficiently convert large amounts of text into speech using Amazon Polly while minimizing costs, a fully serverless, event-driven solution is implemented using AWS Lambda, Amazon S3, Amazon DynamoDB, and AWS Step Functions. Users upload a YAML-formatted set file containing text phrases to an S3 bucket, which triggers the process. The Set Processor Lambda function parses the file and queues synthesis tasks in Amazon SQS, which are then processed by the Item Processor function, submitting requests to Amazon Polly asynchronously. Once synthesis is complete, the Response Processor function renames and stores the generated audio files in S3 while updating task status in DynamoDB. AWS Step Functions orchestrate the workflow, monitoring progress and sending notifications via Amazon SNS upon completion.
This strategy ensures parallel processing, scalability, and cost efficiency by leveraging pay-as-you-go pricing, allowing synthesized audio to be stored and replayed without additional charges.
With a non-serverless model, you’re paying for always-on infrastructure, even when it's idle. This model typically results in higher fixed cost.
By using a serverless approach, you can save approximately 94.4% in costs compared to a non-serverless solution. This substantial savings is primarily due to the pay-as-you-go nature of serverless computing, which avoids the need for provisioning and maintaining always-on infrastructure like EC2 instances.
Instead of synthesizing speech in real time, pre-generating the required speech files and storing them in an Amazon S3 bucket for reuse is a more efficient approach. This eliminates redundant synthesis requests and allows unlimited playback at no additional cost. The implementation involves identifying frequently used phrases or sentences, converting them into speech files using Amazon Polly, and storing the audio files in Amazon S3 for direct access.
This method is particularly useful for applications such as public announcement systems in airports and bus stations, pre-recorded responses for customer service bots, and interactive media like video games.
Amazon Polly offers Standard and Neural voices, with neural voices being more expensive. Selecting the appropriate engine based on the use case helps reduce costs. To optimize spending, Standard Voices should be used for applications where high-quality neural voices are unnecessary, while Neural Voices should be reserved for premium applications requiring a more natural tone. Additionally, testing multiple voices allows users to find the best balance between cost and quality for their specific needs.
By adding these extra factors, we help paint a fuller picture of when and why you'd choose Standard versus Neural voices depending on the needs of your application, your budget, and your audience. This gives users more context to make informed decisions about Amazon Polly's voice options.
The Speech Synthesis Markup Language (SSML) is a markup language specifically designed to control how text is converted into speech. It provides a range of features to dynamically modify the speech output without needing to create new audio files or make additional API calls. By using SSML, you can control the prosody (such as pitch, rate, and volume) and speech emphasis, allowing for a more natural-sounding speech experience with dynamic adjustments. SSML helps reduce costs by enabling real-time changes to speech characteristics within the same audio file. For example, if you want a phrase to be spoken slowly or with emphasis, you can insert SSML tags like <prosody rate="slow"> or <emphasis> around specific text.
Without SSML, you might need to generate separate audio files for every variation of speech (e.g., one file for the standard voice and another with slower speech). By using SSML, you can alter these properties dynamically, leading to fewer API calls and lower usage charges. Additionally, SSML streamlines workflows by reducing the need to regenerate audio for every minor tweak, cutting down on storage costs (fewer audio files to store) and preventing additional compute costs associated with unnecessary audio generation.
The AWS Free Tier is a promotional offering that allows users to access a limited amount of AWS resources for free, either every month or for a certain duration (typically the first 12 months). Amazon Polly, part of AWS, offers free usage under the AWS Free Tier for Standard TTS voices. This is an excellent option for smaller projects, testing, or low-volume workloads.
Amazon Polly is used by companies like FICO, GE Appliances, Best Western, Twilio, Vonage, and National Australia Bank for lifelike speech in customer service, banking, and healthcare. Other users include Credit Saison, PolicyBazaar, Inhealthcare, and Pillo Health.
Amazon Polly offers powerful TTS capabilities for various applications, but understanding its pricing model and optimizing costs is crucial for maximizing efficiency. By implementing serverless processing, pre-generating speech files, selecting the right voice engine, using SSML, and leveraging AWS Free Tier, businesses can significantly reduce expenses while delivering high-quality speech synthesis solutions.
2. Optimize your budget and time by submitting Amazon Polly voice synthesis tasks in bulk
3. AI Voice Generator and Text-to-Speech Tool - Amazon Polly
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