Spex-TTS
Spex-TTS: A developer-focused TTS API for conversational applications needing cloning and streaming. Ranked #53 of 222 in Text-to-Speech Software by our editors (4.1/10); pricing: Free plan; best for conversational API builders needing expressive cloning.
At a glance
- Editor score4.1 / 10
- PricingFree plan
- Best forConversational API builders needing expressive cloning
- Free planYes
- Paid from$10/mo
- Facts checked20 Sep 2026
Where it wins
- Streaming through REST, SSE, and WebSocket interfaces
- Instant voice cloning from about ten seconds of reference audio
- 23 languages with per-request expression controls
Where it doesn't
- Generated audio includes inaudible watermarking
- Formal certifications, including SOC 2, are not complete
- Published pages do not state explicit commercial-use permission
Our verdict on Spex-TTS
Spex-TTS is Gandr’s text-to-speech engine for developers and businesses building voice agents, narration, dubbing, live translation, and other audio applications. It is available through web and API interfaces, with REST, server-sent events, and WebSocket access. The service generates speech in 23 languages, supports voice cloning from about ten seconds of reference audio, and returns WAV or raw PCM audio. Its feature set is aimed at teams building conversational and real-time voice products rather than users seeking a basic, no-code narration tool.
Pricing ranges from a free plan with 50,000 tokens to start, to Take a Gandr at $10 per month for 1 million tokens and Pro at $50 per month for 5 million tokens. Both paid token plans reset monthly. Scale / flat rate costs $150 per stream per month with annual billing or $180 per stream per month with monthly billing, and provides one unlimited, unmetered stream. Enterprise includes volume, burst, and failover arrangements. The plan structure gives developers a low-cost entry point and a clear path to higher token allowances or an unlimited stream.
Spex-TTS stands out for real-time delivery and request-level control. Developers can use SSE or WebSocket streaming for conversational calls, while controls include temperature, CFG weight, seed, breaks, and spelling tags. Inaudible watermarking is applied to generated audio, and Gandr states that customer text and reference audio are not used for model training. Vapi is the listed integration. Teams that need formal certifications, published commercial-use permission, or a broader verified ecosystem should evaluate alternatives; teams building API-driven voice agents and expressive streaming workflows should consider Spex-TTS.
Your product? Our editors can test Spex-TTS in depth and publish a review, labelled as paid · from $149/mo →
Spex-TTS pricing
All 5 Spex-TTS plans and prices →
Spex-TTS fact sheet
| Free plan | Yes |
|---|---|
| Paid from | $10/mo |
| Commercial use | Not verified |
| Voice cloning | Yes |
| API access | Yes |
| Languages | 23 languages |
| Maximum input | Not verified |
| Export formats | ["WAV", "raw PCM (pcm_s16le)"] |
| Platforms | ["web", "api"] |
| Deployment | Cloud |
| Platforms | Web |
| Support | Email, Docs |
| Built for | Small business, Mid-market, Enterprise (editorial estimate) |
| Integrations | 1 integrations: Vapi |
| Pricing | Free plan (source) |
| Website | gandr.ai |
| Facts checked | 20 Sep 2026 |
Spex-TTS integrations
Spex-TTS lists 1 integrations on its own site.
- Vapi
Alternatives to Spex-TTS
- ElevenLabsAffordable voice cloning with multilingual generation, dubbing, streaming, and API access.9.4
- Google Cloud Text-to-SpeechA broad, API-only TTS service for developers building voice-enabled products.9.3
- Azure AI SpeechA broad, production-ready TTS platform for teams building voice applications.9.2
See all Spex-TTS alternatives →
Used Spex-TTS? Be the first to review it
The editor score above is our own research. What this page doesn't have yet is a reader's view — what you used Spex-TTS for, what worked and what didn't. No stars are seeded and no review is paid for; an editor reads every one before it appears.
Write a reviewTwo minutes · verified accounts only · read by an editor before it appears
Featured on iTechGuides
Spex-TTS is listed in our Text-to-Speech Software directory. Add the badge to your site — it links back to this page.
<a href="https://www.itechguides.com/products/spex-tts/"><img src="https://www.itechguides.com/best/badge/spex-tts.svg" alt="Featured on iTechGuides" width="230" height="46"></a>
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
Advertiser disclosure: iTechGuides is reader-supported. Vendors can pay for top positions in our rankings and for a place on other products' pages, and we may earn a commission when you click some links. Bought places stand at the number bought; this page and our disclosure say so. Paying vendors may get a fuller, more detailed review from our editors, and that review can change their score. How we rank.
Last updated · How we research and update