I build a FREE AI Voice Agent - You have to see this!
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How Do You Build a Free AI Voice Agent for Any Website?
In short: Google AI Studio's Build tab can turn a single system prompt into a working conversational voice app, at no cost.
Key takeaways
- Google AI Studio's Build tab can turn a single system prompt into a working conversational voice app, at no cost.
- The demo agent for a Stockholm spa answered questions in Swedish and English, handled interruptions, and after one follow-up prompt quoted exact pricing: 595 SEK per person, 1,190 SEK for two.
- The finished agent gets a shareable URL, which makes it a concrete pitch asset for landing consulting work with local businesses.
Voice agents are usually pitched as expensive enterprise projects. Ani Björkström, a tech consultant based in Stockholm, demonstrated a different route: building a functional website voice agent for free using Google AI Studio, with a real Stockholm spa website as the test case.
Why use Google AI Studio instead of Gemini?
Google Gemini is the consumer version, built for quick chat. Google AI Studio is the right choice when you are creating applications. Its Playground offers Gemini for text, plus tools for images, video, and audio. Two models were available here: Gemini 3 Flash Preview, which is quicker, and Gemini 3 Pro Preview, the most intelligent option and the one used for this build.
What are the steps to build the agent?
The build is a two-stage process: first generate a system prompt, then feed it into a voice app template. The whole flow took minutes.
| Step | Where | Action |
|---|---|---|
| 1 | Playground | Ask Gemini 3 Pro Preview to write a voice-agent system prompt for the target website's URL |
| 2 | Playground | Copy the generated system prompt as text |
| 3 | Build tab | Paste the prompt, select Gemini 3 Pro Preview, choose "create conversational voice apps" |
| 4 | Build tab | Click Build, allow microphone access, and start the conversation |
The Playground also exposes a temperature setting, kept at 1 for this task: raise it for more creative output, lower it for more fact-based answers. The Build tab offers other options too, including image generation, video animation with Veo, and Google Search grounding, plus buttons to view the code, resize for mobile or tablet, download the app, save it to GitHub, or deploy it on Google Cloud.
How well did the voice agent actually perform?
Impressively, with one gap. The agent opened in Swedish, stopped talking the moment it was interrupted, and switched to English on request. It correctly reported Sunday opening hours of 9:00 a.m. to 6:00 p.m. and listed the saunas, including mixed and female-only saunas and a steam room. But it could not give exact treatment details or an entry price. One corrective prompt, asking Gemini to add detailed treatment and pricing information, fixed this: on retest the agent quoted 595 SEK per person for Sunday entry and 1,190 SEK for two people.
How can this become a business opportunity?
The finished app has a URL you can simply copy and share. The suggested next step is direct outreach: contact local businesses, demo the voice agent you built for their website, and ask whether they want a real agent in their production environment. Those conversations can turn a free prototype into paid consultancy engagements.
FAQ
Does building the agent require any coding?
No. Gemini writes the system prompt, and the Build tab generates the application. The code is viewable if you want it, and the app can be downloaded, saved to GitHub, or deployed to Google Cloud.
Which Gemini model should I pick?
Gemini 3 Flash Preview is quicker, while Gemini 3 Pro Preview is the most intelligent. The demo used Pro Preview for both prompt generation and the app itself.
What if the agent gives incomplete answers?
Iterate with follow-up prompts. The demo agent initially lacked pricing detail; one prompt asking for detailed treatment and price information resolved it.
Full transcript of the video (1,729 words, 13 sections)
0:00 Hey, my name is Annie. I want to know how much is the pricing for one time entry for me and my husband on Sunday. Hello Annie, it's lovely to hear from you. The entrance to the bath on Sundays is 595 SE per person. So for two people, the total would be,90 SE or approximately €15. Is there anything else I can help you with regarding Central Badit? Hi, in this video I will show you how to create a voice agent for any website for free. If you haven't met me, my name is Annie. I'm a tech consultant based in Stockholm. Let's get started. Let's open Google I Studio. And here it's important to remember that we need to use Google I Studio instead of Google Gemini because Google Gemini is a consumer version.
0:48 It is for a quick chat with Gemini. But when you create applications the best option is Google I studio. So we will go to Google I studio. From here go to playground where you can see all the options that you can choose. For example you have featured options. Gemini you have live images for creating different images. Then you have video for creating videos and audio. For this tutorial we will use Gemini. And here you can see that we have two Gemini versions. One is Gemini 3 Pro preview and the other one is Gemini 3 Flash Preview. Now the difference is that Gemini 3 flash preview is a bit quicker. However, Gemini 3 Pro preview is the most intelligent model and for that reason we can choose Gemini 3 Pro Preview for this exercise.
1:39 Once we choose the model, we can start to type. And in here, I want to ask Gemini to create a prompt for creating a voice agent for a certain website. And you can choose any website you would like. I'm choosing a spa website located here in Stockholm that I like to go. This is the website for the spa. I will just copy the URL and then I will go back to Google I studio and then here I will type please create a prompt for creating voice agent for this website and that's it we will click on run button it can take couple of seconds because you remember that we choose geminator pro version that is extra accurate and while the model is thinking we can see on the left side we have different setups.
2:32 We have for example the temperature that is right now on one. However, we can either increase the temperature or decrease the temperature. If we want to create more creative tasks then we can increase it. But if we want to be more factbased then we can decrease it. For this task I will keep it on one. And in here we have already an answer from Gemini. You can see it gives us system prompt instruction for voice agent. We will click on copy as text. Once that is done, we will open another Google I studio instance and you can see that right now we are in playground. However, we need to go to build tab. If you click on build, then this window will open and here we can just copy past and we can choose Gemini 3 flash preview. If you remember Gemini 3 flash preview is the model that is quite quick.
3:21 However, I want to use the most intelligent version. So, I will choose Gemini 3 Pro preview in here. And once we choose the model then we can scroll down and here you can see underneath supercharge your app with IE we have nano banana powered up. This is for creating images. Then we have create conversational voice apps for creating voice agents as we want to do for this exercise. But then we can see that there are even different options. There is animate images with VO if we want to create videos. We have even the option use Google search data for searching data and so much more. However, for this exercise, we need create conversational voice apps and we will click and choose this version and click on build button and the application is being built.
4:08 We can see that there are different options in here. Right now we are in preview mode but we can see even the code and then we can even see everything in full screen which means that this chat button will be closed and we can see our application in full screen mode. Then on the right side we have devices. We can choose current screen which is the size of your current device but we can even choose the size of mobile or tablet. Then we have a button for reload the application and we can even download and save this app locally on our computer. We can even save this on GitHub. If we click on save to GitHub and alternatively we can deploy this application on Google cloud. There is another button that is about share the app and we can use this button if we want to share this application.
4:56 We can see that the application was created and it says allow this app to request access to a microphone. Click on allow and here it is. We can see that our voice agent is called central budget which is the name of the website that I used. If I come back in here, you can see that it is the name of the website. We can see the window to nature small text that was taken from central ballot website. And then we have opening hours and today's highlight. So this is looking pretty legit at this point. And let's now start to test it. If we click on start conversation. Hey, my name is Annie and I want to book a visit with my husband on 29th of December. So, you can see that it is talking. It is talking in Swedish, but as soon as I started to talk, it stops, which is amazing.
5:42 So, right now, I will ask you to change the language. Can you please change the language to English? Certainly, I can help you with that in English. You mentioned wanting to book a visit with your husband on December 29th. How can I assist you with that today? Amazing. I'm super excited. Okay. I want to come to Central Bit with my husband on 28th of December. Can you please let me know what are the options that we can book? Welcome to Central Budget. December 28th is a Sunday. On Sundays, we are open from 9:00 a.m. to 6:00 p.m. You can book your entry or any treatments you'd like via our website, centralbodit.se. Is there a specific service you're interested in? Can you please tell me what are the treatments that me and my husband can book?
6:30 We offer a variety of treatments including massages, facial treatments, and nappropathy. You can see all of the available options and book them on our website. Is there a particular type of treatment you are interested in? Do you have different type of saunas? And if you have, can you please list all the saunas? Yes, we have a variety of saunas, including mixed saunas, a female only sauna, a steam room, and our unique Nordic and Tyler saunas. You can relax in all of them after your bath experience. Okay. Can you give information about the pricing? How much it will cost for me and my husband to come and visit you on Sunday? The exact price depends on whether you are just booking entry or also including treatments. You can find the current prices and package options on our website.
7:20 What if I want to just book the entry for me and my husband? Please tell me what is the price of that? I don't have the exact price for entry only. Okay. So, right now we realized that it was working quite good. It could change the languages. However, it doesn't have the detailed information about the different types of treatments. Also, it didn't have the detailed information about the prices. And I want to correct that. Let's ask the Gemini to enter that information. Pay please enter detailed information about all the treat and prices. Then we click on send prompt. Yeah. So in here we have the new version. We have different suggestions as well. For example, it suggest us what are the options of developing this app f.
8:06 So we have list all treatments. For example, add booking info and so on. But let's try to test and see if it now knows about the pricing. Hey, my name is Annie. I want to come and visit central bad tomorrow and I want to know how much is the pricing for one time entry for me and my husband on Sunday. Hello Annie, it's lovely to hear from you. The entrance to the bath on Sundays is 595 SE per person. So for two people the total would be €1,190 SEC or approximately €15. Is there anything else I can help you with regarding central badit? Can you tell me what are the treatments that we have in central bad? Thank you. Certainly. We offer a variety of treatments including classic massages, lymphatic drainage and facials.
8:55 We also offer napy. You can find a full list and book your treatment on our website. Would you like me to give you an example of the price for a specific treatment? No, that's fine. Amazing. Thanks a lot. Here we can just finish the conversation as I did right now. And the next option that I want to show you is that this is a very good business opportunity for you. So what you will do in the next step and from here you can just copy the URL. Now the next step is actually contacting a lot of local businesses, sharing your voice agents and asking if they want real agent for their production environment. Please make those calls because you can land on different consultancy opportunities and let me in the comments how this goes.
9:40 If you like this video, please click on the like button and have a good day. But
Want this working inside your finance team?
Ani Björkström — founder of QvantX Sweden AB, a Stockholm consultancy building AI solutions for banks, asset managers and finance teams. Anthropic partner. Every article starts from a real client build, minus the confidential parts. LinkedIn →
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