By Mehdi Hassan3D on a marketing site is a choice you should make on purpose. When it works, it shows a physical product, a spatial idea or a brand world in a way flat images can't. When it doesn't, it's a heavy canvas that delays the headline. This comparison sits within our website animation guide and assumes the 3D has a job to do. If it doesn't, the best tool is neither.
Three.js vs Spline: what's the difference?
Three.js is an open-source JavaScript library for rendering 3D in the browser, while Spline is a browser-based 3D design tool that exports scenes to the web. With Three.js, a developer writes code that loads models, sets up lights and cameras, and handles interaction. With Spline, a designer builds the scene visually, adds states and events, and publishes it as an embed or exports it for code.
Spline | Three.js | |
|---|---|---|
What it is | Visual 3D design tool with web export | Open-source 3D rendering library |
Who builds it | Designer, no code needed | Developer, in JavaScript |
Interaction | States and events set in the editor | Anything you can code |
Control over weight | Limited to what the export allows | Full: models, textures, render loop |
React and Next.js | Official React component for exported scenes | React Three Fiber for component-based scenes |
Who updates it | Designer edits the scene and republishes | Developer changes code and redeploys |
The gap is less about visual quality, since both can look excellent, and more about control and ownership. Spline trades some control for speed and designer independence. Three.js trades setup time for precision.
When is Spline the right choice?
Spline is the right choice when a designer wants to build, tweak and ship a 3D scene without waiting on a developer, and the scene is a contained brand moment rather than a product feature. Hero objects that rotate on hover, floating shapes that react to the cursor, and simple interactive product teasers are where it fits best. The editor handles materials, lighting, states and events visually.
Pros
- Designers can create and update scenes without code
- Fast path from idea to live embed
- Collaborative, browser-based editor
- Official ways to use exported scenes in React or plain JavaScript
Cons
- Less control over the runtime, file weight and render loop
- Complex scenes can get heavy for phones
- Deep custom logic still needs code around the export
- Plan features and limits change, so check Spline's current pricing page
Spline also suits teams that prototype a lot. A designer can test three hero concepts in the editor before anyone commits to engineering time. If you're weighing whether the hero should move at all, see hero section animation patterns.
When is Three.js the right choice?
Three.js is the right choice when the 3D is part of the product story and needs precise control: custom interactions, scroll-linked camera moves, data-driven geometry or tight performance budgets. Because it's code, you decide exactly which models load, how textures are compressed, when the scene renders and what happens on a slow phone. Three.js includes a WebGL renderer and a newer WebGPU renderer.
Pros
- Full control over loading, rendering and interaction
- Huge ecosystem of examples, loaders and helpers
- React Three Fiber makes scenes reusable components in Next.js
- No vendor lock-in; it's open source
Cons
- Needs a developer with 3D experience to build and maintain
- Longer setup before anything looks good
- Easy to ship a scene that's too heavy without a budget
- Designers can't change it without going through code
In React and Next.js projects, we reach for React Three Fiber, the React renderer for Three.js, with its companion helper library drei. It lets 3D sit inside the same component system as the rest of the site, which matters when the scene responds to page state. If your site is moving to code for reasons like this, our take on a Next.js marketing website covers when that's worth it.
How do Three.js and Spline compare on performance?
Three.js usually wins on performance because you control every byte and every frame, but a carefully built Spline scene can be perfectly fine for a single hero object. The real costs are the same in both: model complexity, texture size, the JavaScript runtime and rendering frames when nothing is changing. Spline hides some of those choices; Three.js exposes all of them.
- Never block the headline. Render the hero text and a static poster image first, then load the 3D. web.dev defines a good Largest Contentful Paint as 2.5 seconds or less.
- Compress models and textures. In Three.js, use glTF models with mesh compression and compressed textures. In Spline, simplify geometry and reduce texture sizes before exporting.
- Render on demand. React Three Fiber can render only when something changes instead of every frame, which saves battery on idle scenes.
- Cap pixel density on phones. Rendering at full device pixel ratio on high-density screens multiplies the GPU work.
- Pause off screen. Stop the render loop when the canvas scrolls out of view.
The same scroll and main-thread rules apply to 3D as to any motion, and they're covered in scroll animations without killing performance.
For example, suppose a hardware startup wants a 3D product in the hero
For example, suppose a hardware startup has a CAD model of its device and wants visitors to rotate it in the hero, then see three features highlighted as they scroll.
With Spline, a designer imports a simplified model, sets up materials and lighting, adds a hover rotation, and publishes an embed without a developer. The scroll-linked feature highlights would need extra code around the export.
With Three.js and React Three Fiber, a developer loads a compressed glTF version of the model, ties camera positions to scroll progress, and swaps in a static image for phones and reduced-motion visitors. It takes more build time, but every step is controlled and the scene shares state with the page.
If the scroll story is the main explanation on the page, Three.js is the safer bet. If the hero only needs to look striking and the team wants to iterate visually, Spline is.
Who maintains 3D after launch?
Spline scenes are maintained by designers, Three.js scenes by developers, and that's often the deciding factor. A startup that changes its hero every quarter needs whoever owns the brand to be able to update the 3D. A product team with engineers on staff may prefer code it can review, version and test like everything else.
Think about the next two years, not just launch. If the scene lives in a Spline account, decide who owns that account and how embeds are updated. If it lives in code, make sure more than one developer understands it. Teams moving from a coded site to a visual builder face the same ownership question, covered in moving from code to a visual builder. Also add the 3D embed to your uptime monitoring checks if it loads from a third-party host.
How do you make website 3D accessible?
Treat a 3D canvas as an image: give it a text alternative, keep important content in HTML, offer a static version under reduced motion, and make any controls keyboard-operable. Screen readers can't see inside a canvas. Rotating and zooming scenes can also cause discomfort for people with vestibular disorders, which WCAG's Animation from Interactions criterion addresses.
- Label the canvas with a short description of what it shows, or hide it from assistive technology if it's purely decorative.
- Keep words in HTML. Feature names, captions and calls to action belong in the page, not baked into textures.
- Honor prefers-reduced-motion by showing a still render and disabling auto-rotation and scroll-linked camera moves.
- Use real buttons for any interaction, so keyboard users can rotate or switch views without a mouse.
For how to check this before launch, see how to test website accessibility, and for what the law expects, our overview of WCAG, ADA and the EAA.
Which should you use for a marketing site versus a product experience?
Use Spline for marketing-site brand moments a designer will keep updating, and Three.js for product experiences where 3D carries the explanation or needs tight control. Many sites need neither, and a well-shot product image or a short video does the job with far less weight. If 3D is the main reason for a redesign, a homepage-only redesign may be enough to test it.
When we build 3D in code, it's part of our Next.js development work, with the scene treated as a component that has its own performance budget and fallback. For a one-page launch, our landing page design process decides first whether 3D earns its place at all.
