Voice AI developer tools
Every listing tagged voice, A to Z: 13 tools across 2 categories. Listed in alphabetical order, not ranked.
Amazon Polly
AWS's text-to-speech service: Generative, Long-Form, Neural and Standard voices billed per character, with Speech Marks for lip sync and word highlighting, and free replay of audio you cache.
AssemblyAI
Speech-to-text API: Universal-3.5 Pro transcribes recorded audio in 18 languages, Universal-2 in 99, and Universal-3.6 Pro Realtime streams in 32, with add-ons for diarization, PII redaction, translation and medical terms. An LLM gateway and text-to-speech sit on the same key.
Azure Speech
Microsoft's speech service in Azure AI Foundry: neural and Neural HD text-to-speech voices, custom professional voices and long-form audio, next to speech-to-text and translation, with containers on commitment tiers.
Cartesia
Text-to-speech API built for voice agents: Sonic 3.6 speaks 44 languages and reads confirmation codes without preprocessing, with instant voice cloning. Speech-to-text and voice agents from the same company.
Deepgram
Speech-to-text API: Nova-3 transcribes recorded files and live streams in 60+ languages, Flux adds turn detection for English voice agents, with diarization, keyterm prompting and redaction, billed per second. Aura-2 text-to-speech in 7 languages on the same key, and self-hosted containers on Enterprise.
ElevenLabs Scribe
ElevenLabs' speech-to-text models: Scribe v2 transcribes recorded audio in 90+ languages with keyterm prompting, Scribe v2 Realtime streams text back in about 150 ms, and a HIPAA-eligible medical model. Billed per hour of audio through the ElevenLabs API.
ElevenLabs Text to Speech
ElevenLabs' text-to-speech API: Eleven v4 for expressive speech in 90+ languages with audio tags, v4 Turbo at about 100 ms for agents, and Flash for the lowest latency. Use any voice in your library by ID, clones included. Billed per 1,000 characters.
Google Cloud Text-to-Speech
Google Cloud's text-to-speech API: Chirp 3 HD voices, Gemini-TTS models, instant custom voices, and older Neural2, WaveNet and Standard voices, billed per character with a monthly free allowance on most voice types.
Luke
Open-source (Apache-2.0) Mac app for planning a feature out loud: Luke reads your code while you talk and writes a plan you can paste into Claude Code or Codex.
OpenAI Text to Speech
OpenAI's text-to-speech endpoint: gpt-4o-mini-tts takes prompts for tone, accent and pace, with 13 built-in voices, streaming and custom voices. tts-1, tts-1-hd and gpt-4o-mini-tts shut down on January 6, 2027; the replacement is gpt-realtime-2.1-mini on the Realtime API.
Rime
Text-to-speech API for phone and voice agents: Mist v3 for the lowest latency, Coda v2 for the most natural read in 10 languages, streaming over HTTP and WebSockets, billed by the minute. English pronunciation control, speech-to-text too, and self-hosting on Enterprise.
Speechmatics
Speech-to-text API for recorded and live audio in 55+ languages: Melia 1 follows speakers who switch language mid-sentence, Linden 1 is tuned for voice agents and Oak 1 for clinical terms. Cloud in the EU, US or Australia, or on-prem and on-device on Enterprise.
walkai-talkai
Talk to Cursor, Claude Code or Antigravity over any handheld two-way radio: local Whisper transcription on your Mac types the command, and neural TTS reads the answer back with VOX tones; one-time lifetime license, Apple Silicon.