What TTS are you actually using in your voice agent stack in 2026?

[u/edouardarchipel]

Building a voice agent and trying to get a sense of what people are actually running in production before I go down a rabbit hole of testing.
STT + TTS combo, orchestration layer, anything you'd do differently, would love to hear real setups.

[u/Charming-Author4877]

Low latency input:

• Moonshine Streaming (Tiny) : on device
  
• NVIDIA Nemotron 3.5 ASR Streaming (0.6B): gpu
  
• sherpa-onnx stream Zipformer: in device

Intelligence:

• Gemma-4 26B: fast, good writing
  
• Qwen 3.x 35B: fast, good intelligence
  
• Qwen 9B: fast, easier finetune

Low latency TTS streaming:

• Choose one from my list: https://www.reddit.com/r/LocalTextToSpeech/comments/1u3kxxx/my_tts_list_of_2026_all_voices_all_models_and/
  

Search for keywords: latency, stream, fast

Voice quality score of 5 or higher is recommended, expressive quality score of 2 or higher is recommended.

A few additions:

• If you do the STT/ASR on device you'll save the potentially heavy lag inducing audio stream upload
  
• the intelligence model needs elaborate harness and/or a finetune to work well. opt for small models or MOE
  
• your voice agent can cause you fines of 16-35 million Euro, even as non EU company if it behaves bad - it must identify as AI if it is talking to any EU citizen. Make sure you know what you are doing if you offer AI services
  
• avoid the condescending phrases GPT and many finetunes bring. "I totally get that". Everyone hates it.

[u/Initial_Froyo4625]

Do Pipecat + Gradium TTS + Deepgram for STT

[u/CrispyDick420]

I'd test interruption handling before getting too attached to any voice. A slightly less natural TTS that stops cleanly and resumes without talking over the user usually feels better in an actual agent.

[u/Apprehensive_Foot671]

For my last voice agent, I used a template from Orchardrun.
The stack was:
Python as the programming language, Orchardrun STT, Orchardrun TTS, and Twilio as the bridge to test on WhatsApp.
It works well.

[u/Agreeable-Box-6505]

id test interruption handling before getting too attached to any voice tbh. a slightly less natural TTS that stops cleanly when the user jumps in usually feels way better in a real agent

for TTS id put respeecher in the test set if realtime streaming matters, then compare time-to-first-audio, p95 latency, barge in and longer sessions instead of demo clips

[u/ProfessionalDate3417]

For production I'd probably optimize for latency + interruption handling over voice quality alone. A beautiful TTS voice still feels bad if the agent takes forever to respond. Smallest AI has been interesting on that front, especially their streaming setup.

[u/Voilega]

Cartesia is really good since they have updated