# OfflineTTS vs Amazon Polly: Free Local TTS vs AWS Cloud

> Source: <https://offlinetts.com/blog/offlinetts-vs-amazon-polly/>
> Published: 2026-07-24 00:00:00+00:00

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# OfflineTTS vs Amazon Polly: Free Local TTS vs AWS Cloud

- tts
- comparison
- amazon-polly
- aws
- free

Amazon Polly is AWS’s cloud-based text-to-speech service, popular for its low per-character pricing and tight integration with AWS services. OfflineTTS takes the opposite approach: zero-cost, browser-based, and fully local.

Here’s how they stack up.

## Quick Comparison

| Feature | OfflineTTS | Amazon Polly |
|---|---|---|
Price | Free | $4/1M chars (Standard + Neural) |
Free Tier | Unlimited (all features) | 1M chars/mo (first 12 months) |
Voice Count | 54 + Supertonic/Piper/Kitten | 100+ |
Languages | 9 | 30+ |
Voice Quality | A/A- (Kokoro 82M) | Neural (good), Generative (best) |
Offline | ✅ After initial model download | ❌ Requires internet |
Privacy | ✅ Text never leaves your device | ❌ Text sent to AWS servers |
SSML | ❌ (plain text) | ✅ Full SSML |
API | ❌ (browser only) | ✅ REST API, AWS SDKs |
Signup | ❌ None | ✅ AWS account required |
Voice Cloning | ❌ | ❌ |
Export | WAV, MP3 | MP3, OGG, PCM |

## Pricing: Truly Free vs $4/1M

**OfflineTTS** generates unlimited speech at zero cost — no free tier expiration, no character limits, no credit card required. It runs on your device after the one-time model download.

**Amazon Polly** charges $4 per 1 million characters for both Standard and Neural voices — much simpler than Google Cloud or Azure’s multi-tier pricing. The free tier gives you 1 million characters per month for the first 12 months.

| Volume | OfflineTTS | Amazon Polly |
|---|---|---|
| 100K chars/month | $0 | $0 (free tier) |
| 1M chars/month | $0 | $0 (free tier) |
| 5M chars/month | $0 | $20 |
| 10M chars/month | $0 | $40 |
| 100M chars/month | $0 (or self-host) | $400 |

At scale, OfflineTTS stays at zero. Amazon Polly at $4/1M is the cheapest cloud TTS API — Google charges $4–16, Azure $4–16, ElevenLabs $165+. For high-volume production, Polly is the most cost-effective cloud option.

**Winner:** OfflineTTS for cost. Amazon Polly for cheapest cloud API pricing.

## Voice Quality

**Amazon Polly** offers three voice tiers:

**Standard**— concatenative synthesis, noticeably robotic** Neural**— improved naturalness, the most commonly used tier** Generative**— newest, highest quality (launched 2024)

**OfflineTTS** uses Kokoro 82M (A-grade), Piper, and Supertonic. Kokoro’s top voices match or exceed Polly’s Neural tier in naturalness for short-to-medium speech.

Where Polly excels:

**Consistency**— decades of tuning, very reliable output** SSML control**— full SSML for precise prosody** Generative voices**— new gen-AI voices are competitive with Kokoro

Where OfflineTTS excels:

**No latency**— instant generation on WebGPU** Cost at volume**— free vs $4/1M adds up** Privacy**— no data transmitted

**Winner:** Tie for quality. Polly has more options; OfflineTTS’s best voices compete well.

## Privacy & Offline

**OfflineTTS** processes everything on your device. Text never reaches a server. English works fully offline after the model download. Non-English uses a lightweight phonemization service before local synthesis.

**Amazon Polly** sends your text to AWS servers. While AWS has strong security certifications, the architecture requires data transmission for every request. No offline mode exists.

For applications handling sensitive data — legal, medical, financial — OfflineTTS’s local-only processing eliminates the compliance risk of transmitting speech data.

**Winner:** OfflineTTS — on-device processing is fundamentally more private.

## SSML & Speech Marks

**Amazon Polly** supports:

- Full SSML:
`<break>`

,`<prosody>`

,`<emphasis>`

,`<say-as>`

,`<phoneme>`

,`<sub>`

,`<lang>`

,`<audio>`

,`<p>`

/`<s>`

**Speech Marks**— word-level timing data (word boundaries, sentence boundaries, visemes)** Lexicons**— custom pronunciation dictionaries

**OfflineTTS** accepts plain text only. No SSML. No speech marks. Pacing is controlled through punctuation.

**Winner:** Amazon Polly — SSML and speech marks are essential for production workflows.

## API & Integration

**Amazon Polly** provides:

- REST API and AWS SDKs (Python, Node.js, Java, .NET, Go, etc.)
**SynthesizeSpeech** and**StartSpeechSynthesisTask**(async batch)- Integration with AWS services (Lambda, S3, CloudFront)
**Lexicon management** for custom pronunciations

**OfflineTTS** is browser-only with no API. For programmatic TTS, use the [Kokoro Python package](https://github.com/hexgrad/kokoro) directly.

**Winner:** Amazon Polly for API integration. Kokoro Python for local scripting.

## Use Cases

### YouTube and Content Creation

OfflineTTS wins on cost. Unlimited free generation means you can iterate endlessly. Polly is more cost-effective than other cloud APIs if you need SSML.

### Audiobooks

Amazon Polly’s SSML and Speech Marks are useful for audiobook production. At $4/1M chars, a 100K-word novel costs about $2.40 — very affordable. OfflineTTS is free but has no SSML.

### E-Learning

Polly’s SSML gives fine-grained control over instructional narration. OfflineTTS’s privacy matters for courses with sensitive content.

### Enterprise Applications

Amazon Polly’s AWS integration and reliability make it the standard choice for enterprise TTS in the AWS ecosystem. OfflineTTS doesn’t support programmatic integration.

## The Bottom Line

**Choose OfflineTTS if you:**

- Want truly unlimited free TTS
- Need privacy — text stays on your device
- Need offline capability
- Don’t need SSML or API access
- Produce short-to-medium form content

**Choose Amazon Polly if you:**

- Need the cheapest cloud-based TTS API ($4/1M)
- Require SSML for precise prosody control
- Need Speech Marks for word-level timing
- Are building an application in the AWS ecosystem
- Need custom pronunciation lexicons

**Winner for most users:** OfflineTTS for personal use. Amazon Polly for AWS-native production.

## Related articles

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