How to build an animated AI website with Codex and GPT‑5.5

Modern landing pages are full of motion: looping hero videos, smooth scroll animations, and text that glides into view at just the right moment. Not long ago, this kind of site required a designer, a front-end developer, and a lot of custom code. Now you can get very close to that award-winning look using AI tools end to end.

This guide walks through the full process of building an animated website using AI: from finding visual inspiration, to generating an animated hero video, to building and refining the page layout with Codex and GPT‑5.5.

Overview of the AI-powered workflow

The core idea is to let AI handle both the visuals and the code, while you focus on direction and taste. The workflow looks like this:

1. Find a visual style you like using inspiration boards.
2. Use an image model (via GPT or similar) to recreate that style with your own character or concept.
3. Animate that image into a short hero video using an AI video tool with a reference animation.
4. Use an AI website builder like Codex (powered by GPT‑5.5) to generate the layout and sections from prompts.
5. Ask the AI to wire the video into the hero section and tie playback to scroll.
6. Iterate on typography, spacing, and readability with small, targeted prompts.

You don’t need design or coding experience—your main job is to describe what you want clearly and refine the results.

Step 1: Find and define your visual direction

Before touching any AI tools, you need a visual direction. A simple way to do this is to browse an inspiration platform like Pinterest.

Search for terms that match your niche or product (for example, “futuristic SaaS landing page” or “neon 3D character art”). When you find an image you like, click into it—most platforms will automatically suggest similar visuals, helping you quickly narrow down a style.

Pick one image as your main reference. This will guide the character, composition, and color palette of your hero section.

Step 2: Generate a custom hero image with AI

Once you have a reference, the next step is to create your own version of it using an image model. You can do this directly in a multimodal AI like GPT (for example, via GPT‑5.5 in Codex or a browser-based interface).

Upload your inspiration image and describe how you want to adapt it. For example:

“Create a new 4K 16:9 image inspired by this reference. Make the character larger so only the upper half of the body is visible, centered on the right side, with a clean dark background suitable for a website hero.”

The goal is not to copy the original, but to capture the same mood and composition in a unique way. Once you’re happy with the result, download the image—it will become the base for your hero video.

Step 3: Turn the static image into an animated hero video

To give your site that premium feel, you can animate the hero image using an AI video tool that supports reference-based animation (the transcript mentions Sidon’s tool, used through a platform like Hexfield, but similar tools exist across the AI video ecosystem).

The process typically looks like this:

1. Choose a short reference video whose motion you like (for example, a subtle camera pan and character movement).
2. Upload your generated hero image.
3. Upload the reference video as the motion source.
4. Use a simple prompt such as: “Animate the image in the same way the reference video is animated.”
5. Set basic parameters like duration (e.g., 8 seconds) and resolution (1080p).

After rendering, you’ll get a looping animation where your custom character moves and the camera shifts in a similar way to the reference. This is the video you’ll embed in your hero section.

If you want to go deeper into AI video generation and comparison of tools, check out our coverage of how different models handle complex 3D and motion workflows.

Step 4: Generate the hero section layout with Codex

With your hero video ready, it’s time to build the website. Codex, powered by GPT‑5.5, can generate complete layouts from a single prompt. If you’re new to the tool, our Codex beginner’s guide for GPT‑5.5 is a helpful companion.

Start by describing the hero section you want. You can either:

• Write a fresh prompt from scratch, or
• Reuse a layout prompt you like (for example, from a library such as motionsites.ai) and modify it.

A sample hero prompt might be:

“Create a full-screen hero section with a black background. Include a navbar at the top. On desktop, place the main content (headline, description, button, and small tagline) on the left, and a large video container on the right. Use clean, modern typography and keep the design minimal—no mouse reveal interactions or background textures.”

Send this to Codex or your preferred GPT‑5.5 interface. In one shot, you’ll get the HTML/CSS (and often JS) for a responsive hero with a clear structure.

Step 5: Add supporting sections with AI prompts

Before wiring in animations, it helps to have the rest of the page structure in place. You can ask the AI to extend the layout with additional sections under the hero.

For example, you might request:

• A features section with three cards side by side, each containing a headline, description, and short tagline.
• A simple, centered text section for a key message or manifesto.

A prompt could look like this:

“Under the hero section, add two more sections. The second section should have three cards in a row with a ‘liquid glass’ style: white text, subtle blur, and translucent backgrounds. Each card has a headline, description, and tagline. The third section should be a centered text block (headline, description, tagline), vertically positioned about 50px above the center of the viewport.”

If you have a specific “liquid glass” style snippet (for example, copied from a design system or another project), paste it into the prompt and clearly label it, such as: “Here are the liquid glass styles, apply them to the cards: …”. The AI will integrate that CSS into the generated layout.

Step 6: Tie the hero video to scroll interactions

Now comes the most interesting part: connecting your hero video to scrolling so the page feels dynamic and immersive.

First, upload your video to a hosting service or your project’s assets and grab the direct URL. Then, in Codex or GPT‑5.5, give a focused instruction like:

“Add the following video as the background of the hero section, without any dark overlay. Tie the video playback to scroll so that as the user scrolls down, the video plays from start to finish. As the user continues scrolling, the content sections below should appear progressively.”

If you already have a working scroll-tied video prompt from another project, you can paste it and say something like:

“Implement this interaction logic into our current website. Use this video URL as the hero background. Keep all existing sections and styles, just add the scroll-tied video behavior.”

The AI will typically add JavaScript to control the video’s currentTime based on scroll position and animate the opacity or transform of the text sections so they fade or slide into view as the video progresses.

Step 7: Refine interactions and remove unwanted effects

AI-generated layouts often include extra flourishes like mouse-follow effects or exaggerated scaling. If something feels distracting, you can remove it with a precise prompt.

For example:

• “Remove the mouse interaction that scales the hero video on hover or cursor movement.”
• “Keep the video at its original scale so the character’s head is fully visible, no zoom-in or parallax.”

The model will adjust the CSS/JS, giving you a cleaner, more focused hero. This kind of micro-iteration is where AI really shines: you describe what bothers you, and it rewrites the implementation.

Step 8: Improve typography and readability

Even when the layout looks good, text can be too small, too low on the page, or hard to read against the background. You can fix this entirely with prompts—no manual CSS tweaking required.

Common refinements include:

• Increasing font sizes for headlines and body text.
• Changing font weights for better contrast.
• Moving text blocks higher or lower on the page.
• Simplifying cluttered components (for example, removing decorative numbers and lines).

Example prompts:

“In the hero section, replace the current headline, description, button, tagline, and number lines with this new content. Do not change any other sections.”

“In the third section (the one with the ‘Human shape, future signal’ text), move the entire content block—headline, description, and tagline—150px higher so it’s more readable over the background.”

By referencing specific text (like a unique phrase in the section), the AI can reliably find and adjust the right block without breaking the rest of the layout.

Step 9: Check mobile responsiveness

Finally, preview the site on mobile. A well-structured AI layout should already be responsive, but it’s worth checking:

• Does the hero video scale correctly on smaller screens?
• Is the navbar usable and legible?
• Are text blocks readable without overlapping the video too much?
• Do cards stack vertically in a clean way?

If something feels off, ask the AI to target mobile breakpoints specifically. For example:

“On screens below 768px width, stack the hero content vertically with the text on top and the video below. Increase body text size slightly for readability on mobile.”

After a couple of iterations, you’ll have a fully responsive animated site that looks polished on both desktop and mobile.

Bringing it all together

By chaining image generation, AI video tools, and Codex with GPT‑5.5, you can build complex, animated websites with surprisingly little manual coding. The key is to think in terms of clear, incremental prompts:

• Define the visual style and hero concept.
• Generate and animate a custom image into a short video.
• Use Codex to scaffold the layout and sections.
• Wire the video into the hero and tie it to scroll.
• Iterate on interactions, typography, and spacing until everything feels readable and intentional.

Once you’re comfortable with this workflow, you can reuse your best prompts across projects, swap in new visuals, and quickly spin up high-end landing pages for different products or clients—all powered by AI.