How do Ultravox and Kawl Now compare?
The difference is how much you build: Ultravox gives developers the model, the API and the SDKs, while Kawl Now gives you two configured agents and a widget. We checked Ultravox’s official pages on 8 October 2026.
| Consideration | Ultravox | Kawl Now |
|---|---|---|
| What you get | A hosted voice AI platform and API, built on its own speech model. | A support agent and a sales agent for your website. |
| Who builds it | Your developers, in code. A no-code console is there for building and testing agents. | Your team, in a dashboard. The only code is one script tag. |
| On your website | A JavaScript SDK over WebRTC. You build the interface and a server that creates each call. | A voice widget with live captions, mute and an end button. |
| Phone calls | Inbound and outbound through Twilio, Telnyx, Plivo, Exotel or SIP. | No phone number for customers to call. Visitors talk in the browser. |
| Knowledge | Crawled web pages or uploaded files such as PDF, Word and Markdown, searched with a built-in tool. | FAQs, notes and selected GitHub files, each approved before use. |
| Languages and voices | 26 languages, built-in voices, voice cloning or your own text-to-speech provider. | Agents greet callers in English, in one of two voices. |
| Calls at once | Up to 5 on pay as you go, with no hard cap on paid plans. | Up to 3 per workspace. |
| Call records | Transcripts, summaries and optional recordings, kept until you delete them. | Text transcripts, plus automatic insights from recent calls. Kawl Now doesn’t record call audio. |
| Cost to start | 30 free minutes, then $0.05 a minute. | First 50 conversations free per workspace, a one-time allowance. Paid calls aren’t available yet. |
What is Ultravox?
Ultravox is both a speech model and a hosted service. The model is open-weight, and Ultravox says it processes speech directly, without a separate speech recognition stage, so the tone and pacing of what callers say aren’t lost in transcription. Its current model, ultravox-v0.7, is built on the GLM 4.6 language model.
Ultravox Realtime is the hosted service that runs it. You create a call through the REST API, which returns a join URL, then connect a person through a client SDK, a phone line or a WebSocket. Ultravox calls itself an API-first platform and says you should expect to write code to put its agents into your applications. Its homepage also says the company has been acquired by Inworld.
What does it take to put Ultravox on your website?
Ultravox’s web quickstart fits in one HTML file, but it comes with a warning: it sends your API key from the browser using an unsafe header, and it must not be used in production. A production site needs a server that creates each call with your API key and hands the browser a join URL. The page then joins the call with the JavaScript SDK over WebRTC, and Ultravox points to a Next.js example for that pattern.
Around those calls, your team builds the call screen and decides who may start calls and how many can run. Ultravox keeps the call history for you, with transcripts, summaries and optional recordings, but its docs describe client SDKs for web and mobile apps rather than a ready-made website widget.
Kawl Now ships those parts. You paste one script tag that carries only a public workspace ID and list the exact sites that may start calls. Before a call starts, the widget tells visitors they’re speaking with AI and that a transcript will be saved.
How does each agent learn about your product?
Ultravox keeps knowledge in corpora. You add a source by crawling URLs or uploading files, including PDF, Word, PowerPoint, Markdown and plain text, then give the agent the built-in queryCorpus tool and tell it when to use it. The pay-as-you-go plan includes 2 corpora and Pro includes 20. Developers can also connect their own vector database as a custom tool.
Kawl Now’s support agent searches FAQs and notes you write, plus selected .md, .mdx or .txt files from GitHub. The sales agent has its own sales notes and never sees support sources. No source is searched until someone approves it, and every GitHub re-sync needs approval again. A workspace holds up to 100 sources of up to 50,000 characters each.
So Ultravox takes more formats and can crawl a site, while Kawl Now adds a review step before a new or changed source is used.
How much does each cost to try?
On 8 October 2026, Ultravox’s pricing page listed 30 free minutes, then $0.05 a minute, which its homepage says includes text-to-speech. Calls are billed in six-second steps. Pay as you go allows five calls at once. Pro, at $100 a month billed yearly, removes that hard cap, adds an outbound call scheduler and raises custom voice clones from 1 to 5 and corpora from 2 to 20.
Kawl Now gives each workspace its first 50 conversations free, shared by support, sales and your own tests. Calls last up to 10 minutes and up to three can run at once. Paid calls aren’t available yet, so no payment is collected and new calls stop when the 50 are used.
When is Ultravox the better choice?
Ultravox fits better when you have developers and need more control or more channels. Look at it first if you need:
- Voice inside your own web or mobile app, with your own interface and call flow.
- Phone calls through your own carrier, inbound or outbound, including cold or warm transfers to a person.
- Languages other than English, a cloned voice or your own text-to-speech provider.
- Tools that act in your systems, multi-stage call flows or webhooks.
- High call volumes, with no hard cap on concurrent calls on a paid plan.
When does Kawl Now make more sense?
Kawl Now suits a SaaS team that wants spoken answers to product and buying questions on its own website, without building a call server and a call interface. It runs on OpenAI’s GPT-Live rather than a model you choose, greets callers in English, has no phone number for customers to call and can’t act in other systems. If that fits, it gives you:
- Separate support and sales agents, each with its own knowledge, greeting, voice and widget.
- Search limited to sources your team has approved.
- Limits handled for you: up to 10 allowed sites per agent, 10-minute calls, three at once and 12 new calls a minute.
- Two-sided transcripts in the dashboard, plus a REST API and an MCP server for coding agents.
Common questions
Is Ultravox free to try?
Yes, up to a point. On 8 October 2026, Ultravox listed 30 free minutes of calls and unlimited calls in its console’s playground, then $0.05 a minute on pay as you go. Kawl Now gives each workspace its first 50 conversations free, shared by support, sales and tests, with no card required.
Does Ultravox have a website widget?
Not a ready-made one. Its docs describe a JavaScript SDK for web apps, and its one-file quickstart warns that it exposes the API key and isn’t safe for production, so a live site needs a server that creates each call. Kawl Now installs with one script tag.
Why can an Ultravox transcript differ from what the agent heard?
Ultravox says its model hears audio directly and never reads a text transcript. The transcripts in its call history come from a separate speech recognition system and exist to help you read calls, so a transcript can be wrong even when the agent understood the caller. Ultravox suggests listening to the call recording to check.