Amazon Polly vs Google Cloud Text-to-Speech

Amazon Polly 70

Read as a model, from the Polly service model and the document history. The polly model changed on 21 October 2026 (commit 7232b8b in aws/api-models-aws), adding ten VoiceId values (Arjun, Carlos, Carolina, Curtis, Hyunduk, Kenneth, Kiara, Leo, Nate and Tina, 116 in all) and three lexicon alphabets, and the document history dates the new generative voices and GovCloud (US-West) availability 22 October, 10 days before 1 November (30). Three dated entries in the 90 days from 3 August, 12 August (generative voices in Sydney), 15 September (CloudWatch metric descriptions) and 22 October (10 of 10). No deprecation policy or dated notices for voices or engines found. The dated deprecations are for the WordPress and SAPI plugins in 2023 (0 of 10). Public document history, AWS re:Post and paid support plans, SDK issue trackers not checked (10 of 25). Official SDKs current in Python, JavaScript, Java, Go and others (15). SDK package health not checked (5 of 10). 30 + 10 + 0 + 10 + 15 + 5 = 70.

Google Cloud Text-to-Speech 25

Read as a model. The newest release note is still 30 December 2025 (Chirp 3 HD in yue-HK), 311 days ago, and gemini-3.1-flash-tts-preview appears on the Gemini-TTS page with no dated note (0). In the 90 days from 8 August the Python client shipped 2.38.0 on 1 October, whose only change declares Python 3.15 support, which counts half and can't set the recency line (0). Release notes, a public issue tracker and paid support (10 of 15). Official client libraries, Python at 2.38.0 and Node at 7.2.0 (10 of 15). Package CI not checked (5 of 10). Total 25.

Amazon Polly 82

API reading of the checklist. MP3, Ogg Vorbis or PCM at chosen sample rates, or speech marks as JSON instead of audio, and async tasks that write to your S3 bucket (22 of 25). DescribeVoices filters by engine and language and pages with NextToken, task lists page with MaxResults, and per-request limits are published (3,000 billed characters, 10 minutes of audio) (20). Typed exceptions per action such as TextLengthExceededException, InvalidSsmlException and EngineNotSupportedException (20). Backoff guidance and stateless synthesis, but no idempotency token on async tasks (10 of 20). Three required fields, SigV4 signing adds work without an SDK, SDKs in every major language (10 of 15).

Google Cloud Text-to-Speech 65

API reading of the checklist. Audio returns Base64 in JSON or streams over gRPC, with encoding, sample rate and timepoints selectable (15 of 25). voices.list filters by language code with no paging, and operations list with page tokens (15 of 20). Standard gRPC status codes with messages, generic rather than TTS-specific (15 of 20). Synthesis is stateless and long audio runs as an operation, with no idempotency key (10 of 20). A first call needs a project, billing, OAuth credentials and a voice, and Cloud Storage for long audio. Official client libraries in many languages, of which Python and Node were checked (10 of 15). Total 65.

Amazon Polly 90

The service model is public in the AWS SDKs (botocore and the JavaScript v3 clients), a machine-readable contract in the role OpenAPI plays (25). llms.txt for the developer guide (10). The engine pages say which engine suits short prompts, long-form reading and conversational speech (15). Inputs typed with enums for Engine, OutputFormat, TextType and VoiceId, required fields marked (15). Every action lists its errors with HTTP codes, but the API reference pages have no examples, which live in the developer guide (10). API version 2016-06-10 and a dated document history (15).

Google Cloud Text-to-Speech 80

Discovery document revision 20260827 with typed methods and 26 schemas, and protocol buffers for gRPC (25). No llms.txt found (0). The Chirp 3 HD and Gemini-TTS pages say which voices suit which use and list formats and limits, but the reference doesn't say when to choose streaming or long audio (15 of 20). Typed messages with enums for encoding and gender and required fields (15). Samples in several languages, standard status codes with little method-specific error detail (10 of 15). Versioned v1 and v1beta1 with dated release notes (15). Total 80.

Amazon Polly 30

No x402, MPP or L402 (0). Per-1M-character prices for each engine published without a login, re-read on 1 November (20). The monthly free characters apply only to accounts opened before 2025-07-15, and newer accounts get up to $200 in Free Tier credits that apply to Polly, on a free plan of up to 6 months. The Free Tier FAQ says a payment method isn't required for most new customers, but AWS's account docs read on 1 November say AWS might request payment information and holds USD $1 to verify, so half, as on the S3 and Secrets Manager re-checks (10). A person signs up in a browser. IAM can mint keys by API, but only after a human has an account (0). 0 + 20 + 10 + 0 = 30.

Google Cloud Text-to-Speech 20

No x402, MPP or L402 (0). Per-character and per-token prices for every voice family published without a login (20). Monthly free characters (1 million for Chirp 3 HD, 4 million for Standard and WaveNet) need billing enabled, which needs a card (0). A person creates a project and billing account in a browser (0). Total 20.

Amazon Polly 80

Closed service under the AWS Service Terms, last updated 30 October 2026, with section 50.3 on Polly unchanged (15). The service terms, privacy notice (Last Updated 18 May 2026) and Polly guide agree, a data processing addendum and a public sub-processor list (Last Updated 30 October 2026) exist, but the default permission to use content sits in the service terms rather than the Polly guide (25 of 30). Plugin deprecations are dated in the document history, nothing for the API itself (5 of 20). Sub-processors and regions disclosed, with the region chosen per request. Section 50.3 of the service terms discloses that text kept for service improvement may be stored outside that Region unless the organisation opts out (20).

Google Cloud Text-to-Speech 87

Closed service under the Google Cloud terms, with Apache-2.0 clients (15). The data logging page, the terms and the privacy notice agree that TTS text and audio aren't logged, and a DPA and sub-processor list exist, as read for google-speech-to-text (25 of 30). Release notes mark preview and GA, and the Cloud terms carry notice before a GA capability is discontinued, but Gemini-TTS is moving to the Agent Platform API with no dated notice for the Cloud TTS models (15 of 20). Regional endpoints (global, us, eu and others) and a public sub-processor list (20). Total 75.

Amazon Polly 80

AWS Health Dashboard with per-service, per-region history and RSS feeds (20). The Polly us-east-1 feed carried no events on 1 November 2026 (built 00:39 PDT), and the dashboard history file read that day has no event naming Polly other than the Middle East (Bahrain) me-south-1 multi-service event open since 2 March 2026, where Amazon Polly sits at the same disruption status S3 carries in the UAE event. On 15 September 2026, inside the 90-day window, AWS said it can't restore resources and data hosted only in that Region, and no update has followed. The newest event in the file is API Gateway in us-west-2 on 30 October, not Polly. One major event, read as the S3 and Secrets Manager re-checks read the UAE one (10). The 15 September update leaves the window after 14 December. Quotas published per operation and engine, 80 requests a second for standard SynthesizeSpeech and 8 for neural, long-form and generative, with burst and concurrency figures, re-read on 1 November (15). Throttled calls return HTTP 400 with ThrottlingException and the quotas page says to retry with backoff and jitter, which the SDKs do by default. Synthesis has no side effects, so a retry is safe (15). SLA under the Amazon Machine Learning Language agreement (Last Updated 28 November 2023), which names Amazon Polly, re-read on 1 November (10). GA (10). 20 + 10 + 15 + 15 + 10 + 10 = 80.

Google Cloud Text-to-Speech 85

Google Cloud status page with a per-product history (20). None of the four Google Cloud incidents since 8 August (20 August, 1 September, 8 and 9 October, and the europe-west2 incident of 20 October, which listed Speech-to-Text among 38 products) names Text-to-Speech. The public page shows only broad incidents, so clean is read with that limit (30). Quotas published with numbers, 1,000 requests a minute for most voices, 200 for Chirp 3, 500 for Studio, 100 concurrent streams and 100 long-audio requests a minute (15). The quotas page (last updated 26 October 2026) says nothing about the error a breach returns or how to back off, read as google-speech-to-text was (0). A 99.9 per cent monthly SLA with credits of 10, 25 and 50 per cent, read on 6 November (10). Chirp 3 HD and Gemini 2.5 Flash and Pro TTS are GA, with Gemini 3.1 Flash TTS and Flash-Lite in preview (10). 20 + 30 + 15 + 0 + 10 + 10 = 85.