How to Build an AI-Powered Web App from Scratch
Web applications (often called web apps) are computer programs designed for user interaction and functionality.
The programs enable users to interact with the real-time content on the page and usually include features such as push notifications, live chat, online payments, data processing, user authentication, and social media integration.
For example, web apps include webmail apps such as Gmail and Outlook, online banking apps such as PayPal and Wise, social media platforms such as Facebook and X (formerly Twitter), eCommerce sites such as Amazon and eBay, workplace collaboration tools such as Zoom and Slack, and project management tools such as Monday.com and Trello.
Users can access web apps on any device with a web browser and an internet connection, including smartphones, tablets, laptops, and desktops.
This makes them different from desktop and mobile applications, which are installed onto the respective devices, and native applications, which are preinstalled and configured on the device.
Web apps differ from blogs, news sites, and business pages, including restaurant websites and menus.
Websites are a static collection of interconnected pages that provide users with information and content, rarely interactive or updated in real-time.
Meanwhile, web apps are created to bridge the gap between downloadable software and static websites.
(Image Source: Buildfire)
Here are some of the key advantages of building and launching a web app to support your business:
- Accessibility. Users can access a web app from various browsers, such as Chrome and Google, and from different devices, such as laptops, desktops, tablets, and smartphones. This makes it highly accessible.
- Always up to date. Users don't need to install a web app onto their devices and keep up with software updates. Web apps are automatically updated, ensuring that what a user sees when they access them through an internet browser is always up to date.
- Scalable. Web apps can easily and quickly scale to accommodate increasing user bases or data loads, which enables businesses to expand their services without costly infrastructure changes.
- Protected customer data. Many web apps have advanced security measures, such as encryption, to protect sensitive customer data.
- Improved collaboration. Most web apps allow multiple users to visit the same page or work on the same project simultaneously. This can be very useful for enhancing real-time collaboration among geographically dispersed teams. For example, with Trello, teams in different locations can access shared documents through the web app.
- Cost-effective. Web apps often require a low-cost initial investment and are easy to maintain and update, making them a more cost-effective option than mobile or desktop applications. For example, a single version of a web app can work seamlessly on all browsers and devices, removing the need to create multiple iterations.
Unfortunately, there are also some disadvantages to note when building and launching a web app, including:
- Dependent on internet connectivity. Web apps require the user to have a stable internet connection to function effectively. If the user's internet is slow, they may experience some disruptions, and if they have no connection, they may not be able to access the web app.
- Limited performance. Due to the reliance on web browsers and internet connectivity, web apps can often perform and respond more slowly than native applications, such as Apple's Photos and Mail. These performance limitations can affect the user experience.
- Limited functionality. Some web apps don't offer the same functionality as native apps, especially regarding device-specific features like GPS and cameras.
- Security issues. Although we mentioned that web apps have advanced security measures, they are still vulnerable to various cybersecurity threats, such as data breaches and malware attacks. This can put sensitive information transmitted over the internet at risk.
Business owners and entrepreneurs often need website design and development skills, such as coding and graphic design, to build and launch a web app.
However, with AI-powered tools like Hostinger’s Horizons, business owners and entrepreneurs can build and launch full-stack web apps without writing code.
Follow this step-by-step guide to build an AI-powered web app from scratch using Horizons.
- Web apps enable real-time interactions, differing from static websites and downloadable applications.
- Key benefits include accessibility, automatic updates, scalability, data protection, and collaboration features.
- Disadvantages involve reliance on internet connectivity, limited performance, and potential security vulnerabilities.
- AI tools like Hostinger Horizons allow non-coders to create full-stack web apps easily.
- The article provides step-by-step guidance on building an AI-powered web app with Hostinger Horizons.
How To Build An AI-Powered Web App With Hostinger Horizons
Step 1. Describe what you want to create.
Tell Hostinger's AI tool more about your web app idea by writing a brief prompt (known as messages on Hostinger Horizon). For example, ‘create a web app that allows users to find like-minded people to attend events such as concerts, sports games, and art exhibitions'.
This section also has prompts for premade web apps, such as a QR code maker, a game, or an image compressor, which you can click to fast-forward to step two.
Step 2. Improve and edit with prompts
Next, you will see a lot of code as the AI model outlines each step of the implementation process so that you know what it is building. For example, ‘create a modern, visually appealing interface' and ‘add event listing and filtering functionality'.
(Image Source: Hostinger)
Following this, the AI model will tell you what it has created so far. For example, ‘a profile page for users to set up their preferences’. You can continue to type messages and attach files to improve and edit your web app, ensuring it is exactly as you envisioned. For example, if you think your web app lacks a section for group travel to each event, then let the AI model know that is what you want.
In addition, the AI model may ask you questions about data management and give you the best advice on how to store data.
Step 3. Go live
Once your web app looks and works how you want it to, you can publish it instantly with just a few clicks. However, you do need to have a paid plan to do this.
How Much Does Hostinger Horizons Cost?
You can get through steps one and two without paying a penny, but you can only send up to five messages to the AI model. Additionally, you cannot publish your web app and set it live online without purchasing a plan.
Hostinger Horizons plans range from $9.99 to $99.99 a month, depending on what is included.
The most basic plan, Explorer, allows you to send just 50 messages to the AI model monthly. The Hustler plan will enable you to send up to 500 messages monthly. The higher the message allowance, the more you can edit and improve your web app by sending prompts to the AI model.
All Hostinger Horizons plans allow you to create 50 web apps and offer a 30-day money-back guarantee, 24/7 customer support, one month of free web hosting, unlimited bandwidth, and easy domain connection. In addition, you can cancel your paid subscription at any time.
Ready To Build An AI-Powered Web App?
Hostinger Horizons lets you build and launch an AI-powered web app in just a few minutes, with little development, design, and coding experience. This can help business owners and entrepreneurs put their services in front of a wide range of users, enhance service accessibility, improve user collaboration, and save money.
Whether you want to create a social media platform, an eCommerce site, a workplace collaboration tool, or anything else, you can use Hostinger Horizon to get started. Remember to ensure your web app has a mobile-friendly interface, as smartphones account for 63% of the world's web traffic.
How to Build an AI-Powered Web App from Scratch: FAQs
Do I need to be a coding genius to build an AI web app?
Here's the thing – you don't need to be the next Einstein to build an AI app. You need to be persistent and willing to learn. I see people spending months “getting ready” to start coding. Stop it. Start with a simple tutorial, build something rubbish, then make it less rubbish. The difference between someone who builds apps and someone who doesn't isn't intelligence – it's starting before you feel ready.
Which programming language should I learn first?
Python or JavaScript. That's it. Don't overthink this. Python, if you want to focus on the AI bits (machine learning, data processing). JavaScript is used to build the front-end that users see. Pick one, stick with it for 3-6 months, then add the other. People who try to learn five languages at once learn none properly.
How much will it cost me to build and run an AI web app?
Most people think it costs thousands. Reality? You can start for under £50 per month. Domain (£10/year), hosting (£20/month), AI API calls (£10-30/month for starting). The expensive part isn't the tech – it's your time. Budget 6-12 months of learning if you're starting from scratch. Your most significant cost is not quitting when it gets difficult.
Should I use ChatGPT's API or build my own AI model?
Use the API. I see beginners thinking they need to train their models like Google. You wouldn't build your own electricity grid to power your house, would you? OpenAI, Anthropic, and others have spent billions building these models. Use their APIs, focus on solving actual problems for real people. You can always make custom models later when you have revenue.
What's the biggest mistake beginners make when building AI apps?
They build solutions looking for problems. They think, “I'll make an AI that writes poems about cats” without asking if anyone wants that. Start with a real problem you or someone you know has. Then figure out if AI can help solve it. The best apps solve boring issues well, not exciting problems poorly.
How long does it take to build a working AI web app?
For a basic app that works? 2-4 weeks if you know what you're doing. 3-6 months if you're learning as you go. But nobody tells you that “working” and “good enough to charge money for” are different things. Most people quit after building the basic version because they think they're done. The real work starts after you have something working.
Do I need to understand how AI models actually work inside?
No more than you need to understand combustion engines to drive a car. You need to know enough to use them effectively – what inputs they take, what outputs they give, how much they cost to run. Focus on the practical stuff: prompt engineering, handling API responses, managing costs. Leave the theoretical deep dive for later.
What tech stack should I use for my first AI web app?
Keep it simple: React or vanilla HTML/CSS/JavaScript for the front-end, Node.js or Python Flask for the back-end, PostgreSQL for the database, and deploy on Vercel or Railway. Don't get fancy with microservices and complex architectures. You're not Netflix. Build something that works, then optimise when actual users complain about speed.
How do I handle the costs of AI API calls when users are using my app?
Set limits from day one. Give users a free tier (maybe 10 daily requests), then charge for more. Most people forget to add usage tracking until their first £500 API bill arrives. Implement request limits, user authentication, and usage monitoring before you launch. After all, adding features is easier than adding billing controls.
Should I learn machine learning and data science first?
Only if you want to spend 2 years learning before building anything useful, most successful AI apps use existing models through APIs. You need to know enough to prompt models effectively and handle their responses, not how to train neural networks from scratch. Get good at solving problems first, and become a data scientist later if you want to.
What's the first AI feature I should add to my web app?
Something that saves people time or money. Text summarisation, content generation, or basic chatbots are good starting points because they're simple to implement and immediately useful. Don't try to build the next revolutionary AI breakthrough. Build something that does one thing well, then add features based on users' requests.
How do I know if my AI app idea is worth building?
Find 10 people with the problem you're solving and ask if they'd pay £10-50/month for a solution. If you can't find 10 people, or if they all say “maybe” instead of “absolutely”, pick a different problem. The market tells you if your idea is good – your friends and family will lie to be nice. Trust strangers with money over friends with opinions.
