AI · alternatives · 2026
24 alternatives to Ultravox AI: Fast LLM for Realtime Voice
Build AI voice agents that communicate like we do
Below are 24 products that do a similar job, ranked by how close each is in meaning and then by launch-day votes.
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Last year when GPT-4 was released I started making lots of little voice + LLM experiments. Voice interfaces are fun; there are several interesting new problem spaces to explore. I'm convinced that voice is going to be a bigger and bigger part of how we all interact with generative AI. But one thing that's hard, today, is building voice bots that respond as quickly as humans do in conversation. A 500ms voice-to-voice response time is just barely possible with today's AI models. You can get down to 500ms if you: host transcription, LLM inference, and voice generation all together in one place;…
2024 · fastvoiceagent.cerebrium.ai · its alternatives →
- 2
Daily Bots▲223Build voice-to-voice AI agents with any LLM with Open Source
2024 · daily.co · its alternatives →
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Have a natural, spoken conversation with AI! Contribute to KoljaB/RealtimeVoiceChat development by creating an account on GitHub.
2025 · github.com · its alternatives →
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High-quality voice clones with just 60 seconds of audio
2023 · wavel.ai · its alternatives →
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Retell AI▲296API that helps developers build human-like voice agents
2024 · retellai.com · its alternatives →
- 6
I built a voice agent from scratch that averages ~400ms end-to-end latency (phone stop → first syllable). That’s with full STT → LLM → TTS in the loop, clean barge-ins, and no precomputed responses. What moved the needle: Voice is a turn-taking problem, not a transcription problem. VAD alone fails; you need semantic end-of-turn detection. The system reduces to one loop: speaking vs listening. The two transitions - cancel instantly on barge-in, respond instantly on end-of-turn - define the experience. STT → LLM → TTS must stream. Sequential pipelines are dead on arrival for natural…
Mar 2026 · ntik.me · its alternatives →
- 7
Wavel AI▲289Most realistic and natural AI voiceover & dubbing for videos
2023 · wavel.ai · its alternatives →
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Lightning V3▲311Add AI Voice & Chat Agents directly to your website.
Apr 2026 · smallest.ai · its alternatives →
- 10
AI Voice Cloning▲182Clone any voice in 3 seconds – hyper-realistic and free
2025 · anyvoice.net · its alternatives →
- 11
Voice agents powered by Simba 3.2 the world's #1 voice model
Jul 2026 · speechify.ai · its alternatives →
- 12
Voice Agent API▲118One API to build production-ready voice agents
Apr 2026 · assemblyai.com · its alternatives →
- 13
TLDR: We created a personalised Andrej Karpathy tutor that can response to questions about his Youtube videos in sub 1 second responses (voice-to-voice). We do this using a voice enabled RAG agent. See later in the post for demo link, Github Repo and blog write up. A few weeks ago we released the worlds fastest voice bot, achieving 500ms voice-to-voice response times, including a 200ms delay waiting for a user to stop speaking. After reaching the front page of HN, we thought about how we could take this a step further based on feedback we were getting from the community. Many companies were…
2024 · educationbot.cerebrium.ai · its alternatives →
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Our most capable voice agent is now available via API
Apr 2026 · x.ai · its alternatives →
- 15
Get your whole team (humans and agents!) on speed dial
Jun 2026 · getcarbon.app · its alternatives →
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A low-code , No-Code Voice AI agents for everyone
2025 · vomyra.com · its alternatives →
- 18
The most accurate streaming speech model for voice agents.
Mar 2026 · assemblyai.com · its alternatives →
- 19
AI conducts real-time, voice-to-voice user interviews
2023 · outset.ai · its alternatives →
- 20
Voice Agents▲105Turn expertise into 24/7 client-facing AI voice agents
Apr 2026 · mindpal.space · its alternatives →
- 21
FastBots▲103AI chatbots offering fast and accurate customer support
2024 · fastbots.ai · its alternatives →
- 22
Thinnest AI▲96Build Voice AI Agents in 100+ languages for ₹1.5/min
May 2026 · thinnest.ai · its alternatives →
- 23
Sub-350ms voice AI with simple all-in pricing.
Jan 2026 · customsolutions.ai · its alternatives →
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Ranked by how close each launch is in meaning, then by votes. Prices were read from each product’s own site when checked and can change. Refine with your own description →