Voice is back on the product roadmap, but expectations are higher now.
People want natural turn-taking, fewer dead ends, and answers that match what your systems can actually do — not a script that breaks on the second question. Shortlists of top LLM voice assistants development companies matter most when you’re trying to ship quickly without sacrificing reliability.
What separates a demo from a dependable assistant is the unglamorous work: data connections, guardrails, and careful voice UX. The best firms specializing in LLM-powering voice assistants treat speech, intent, and business logic as one system, then test it like a production feature. The companies below show different paths to that outcome, from boutique product studios to large delivery teams.
Impekable blends product strategy, UX, and AI engineering in a way that’s well suited to voice interfaces. Their teams build chat and voice agents for customer service and process automation, then shape the experience so it feels coherent across screens and calls. If you’re comparing top companies in LLM voice AI, Impekable stands out for pairing voice with strong product design discipline.
A common pattern in their work is building the full experience around the assistant, not just the model wrapper. They integrate expressive text-to-speech through their partnership with ElevenLabs, including multilingual voice capabilities, and connect assistants to modern software stacks. Engagements typically suit teams that want flexible delivery without long lock-ins and value clean handoff documentation.
Services and expertise: AI voice agents, conversational agents, UX/UI, product strategy, cloud integration, modern software builds
Location: San Francisco, CA; San Jose, CA; Sydney, Australia
Agentic Labs is a young team building agentic AI tools for software engineers. Their main product, Glide, helps write technical design docs by pulling context from repositories, sorting tasks, and turning decisions into clear implementation steps. When voice is tied to internal workflows, they can also step in as custom LLM voice assistant developers.
The team stays intentionally small, so communication is fast and decisions don’t drag. Alongside Glide, they do consulting in workflow automation, data services, and conversational AI, which helps if voice is only one part of a wider rollout. They’re a good match for early-stage builds and internal prototypes where speed matters.
Services and expertise: Agentic AI tools, workflow automation, conversational AI, enterprise data services, AI consulting
Location: New York, NY, USA
Team size: 2–10 experts
Portfolio: Glide AI design editor connected to code repos with automated planning and task triage
Infutrix builds custom AI solutions with a clear focus on voice agents and business integrations. Their services cover strategy, NLP tuning, voice UI design, legacy IVR migration, and connections to CRMs and telephony platforms, with multilingual support and analytics baked in. If you need top LLM voice assistant agencies that can bridge voice UX and enterprise plumbing, they bring a practical, implementation-heavy approach.
They also have a broader software bench, including web and mobile development plus adjacent services like blockchain and consulting. That range helps when a voice assistant must live inside a full product, not as a bolt-on. Their portfolio shows repeated work across consumer apps and platforms, which can translate well to voice experiences that need real users and real uptime.
Services and expertise: AI voice agents, IVR migration, NLP tuning, VUI design, CRM and telephony integration, multilingual analytics
AI Agents Plus focuses on custom AI agents and voice assistants built for day-to-day business tasks. They handle voice flows, automation, and reporting dashboards, and work with stacks that include OpenAI models, Claude, LangChain, LlamaIndex, and Vapi. Among LLM-powered conversational AI providers, they’re a good fit when you want a voice agent that fixes a specific workflow instead of a vague “do everything” bot.
They cite a large project history and emphasize collaboration, which often matters more than a flashy demo when teams have to adopt the tool. Their published examples show assistants built for spreadsheets, compliance, procurement, and booking flows. That variety suggests a team comfortable with domain constraints and with wiring assistants into everyday business tools.
Naga Info Solutions builds AI agents and automation systems, including voice assistants that handle human-like conversations across phone, mobile, and web channels. They also promote no-code development, which can speed iteration when business teams need to own parts of the flow. For organizations comparing top companies in LLM voice AI, Naga can appeal when the goal is broad adoption across departments, not just a single pilot.
They’ve been in software development for over 16 years, which often shows up as steadier delivery practices and clearer implementation playbooks. Portfolio details aren’t widely published, but their stated use cases include customer service, data analysis, and workflow automation. This is the kind of shop that tends to fit teams that want an agency to guide rollout as well as build the assistant.
Services and expertise: No-code AI agents, voice assistant systems, AI consulting, automation across channels
Location: Trivandrum (Kerala), India
Team size: 107 experts
Portfolio: Limited public case studies; voice assistant implementations for support and automation
Plavno is a London-based software development company with a long record of shipping AI agents and voice solutions across multiple industries. They build end-to-end products, covering product management, UX, engineering, testing, and support, which helps when voice assistants need durable maintenance after launch. For teams that want best LLM voice AI solutions firms with a deep bench of voice-specific examples, Plavno’s portfolio is unusually concrete.
Their published work includes voice agents for recruiting pre-screening, legal depositions, logistics dispatch, health triage, and security monitoring, plus real-time dubbing and translation tools. That mix shows they can handle speech recognition, LLM reasoning, and multilingual output as one pipeline. Projects like real-time meeting translation also signal comfort with latency and streaming constraints — the difference between “works in a clip” and “works in a meeting.”
Services and expertise: Full-stack builds, AI voice agents, multilingual translation tools, web/mobile apps, modernization
Location: London, UK; additional offices in Poland and Central Asia
Codiant is a global digital solutions provider known for AI voice bot services positioned as a replacement for traditional IVR. They promote micro-second response times, natural conversations, telephony integration, and analytics dashboards, which can be useful when call flows are high-volume and measured. If you need custom LLM voice assistant developers who can staff large implementations across regions, their scale is a clear advantage.
They operate across many countries and maintain ISO certifications, with a sizable in-house engineering group and a long delivery history. Voice projects are described across healthcare, logistics, and retail, alongside broader mobile and portal builds for large organizations. This is the kind of partner that works well when voice is one layer inside a bigger modernization program.
Services and expertise: Voice bots for customer assistance, IVR replacement, telephony integration, analytics, full digital product delivery
Location: USA with offices across the UK, Australia, UAE, India, Malaysia, Singapore, Sweden
Team size: 550+ experts
Portfolio: Voice assistant bots across healthcare, logistics, retail; broader mobile apps and portals for enterprise and public-sector teams
Aegis Softtech offers voice bot development alongside broader software, cloud, and AI services. Their voice bots are designed to handle natural speech, offer self-service, and transfer complex cases to human agents, with positioning across banking, healthcare, and e-commerce. If you’re comparing top LLM-powered voice assistant firms, Aegis fits when you want voice plus traditional engineering under one roof.
They’ve operated for many years and maintain a mid-sized team, which can help with parallel builds and integration work. Portfolio details are not heavily publicized, but they describe deployments across telecom, healthcare, and finance. This tends to suit teams that need a practical implementation partner and a straightforward delivery cadence.
Services and expertise: Voice bot development, conversational AI, NLP, software engineering, cloud and big data
Location: Rajkot, India; Ahmedabad, India
Team size: 50–249 experts
Portfolio: Voice bot solutions and IT systems across banking, healthcare, telecom, retail
22 Software builds AI voice agents and multi-agent systems alongside other emerging tech work like blockchain and AR/VR. They position themselves as a global partner operating through entities in Hong Kong and the UAE, with an international team and a growing delivery record. If you need top companies in LLM voice AI that can combine voice agents with adjacent platforms, their menu is broad.
They describe assistants across customer support and sales, plus industry-focused agents for HR, legal, healthcare, supply chain, finance, and real estate. The range suggests a team used to tailoring the same core agent pattern to different domains. Their structure can be attractive when you want one vendor to cover voice, chat, and surrounding product work without hiring multiple specialists.
Services and expertise: AI voice agents, multi-agent systems, industry assistants, chatbots, testing, mobile/web, Web3, AR/VR
Location: Hong Kong; Dubai, UAE
Team size: 80+ experts
Portfolio: Voice agents for support and sales; domain agents across HR, legal, medical, finance, real estate; broader software and blockchain work
Witzo AI is a platform brand launched by Webomindapps, built on a long track record of web development and delivery across many countries. Their pitch centers on voice, chat, and e-commerce agents that support sales, lead qualification, bookings, and follow-ups, paired with end-to-end build services. For teams seeking top firms specializing in LLM-powering voice assistants that can also handle the surrounding web product, this hybrid setup can be practical.
Webomindapps lists a sizable delivery history and maintains operations in India with an additional office in Canada. While specific Witzo clients aren’t listed, the described agent capabilities map to common business workflows where voice can reduce friction and improve response times. This is a fit when you want a vendor that can build the assistant and the surface it lives in, then keep iterating after launch.
Services and expertise: Voice and chat agents, e-commerce agents, end-to-end AI implementation, web and digital delivery
Location: Bengaluru, India; Toronto, Canada
Team size: 50–249 experts
Portfolio: Witzo agent use cases (support, lead gen, booking, content); Webomindapps delivery history across web and e-commerce projects
Choosing A Voice Assistant Partner That Holds Up
Define success before you pick a vendor: completion rate, containment without handoffs, acceptable latency, and what “safe” looks like when inputs get messy. Then choose a team that can point to real deployments, plus a testing and monitoring plan that survives production, not just a demo. That’s where best firms specializing in LLM-powering voice assistants pull ahead.
A strong partner will also explain tradeoffs without drama: what needs structured data, what can stay generative, and where humans must stay in the loop. Ask to see how they handle fallbacks, multilingual support, and integrations that fail mid-call. If you treat selection like product work, you’ll land on one of the top LLM voice assistant agencies that can ship, stabilize, and keep improving long after launch.
If you want to feature your development agency on this list, email us or submit a form in the Top Choices section. After a thorough assessment, we’ll decide whether it’s a valuable addition.
