lil-gui — Live Parameter Tweaking for Three.js
lil-gui is the modern dat.gui replacement — drop sliders next to your scene to tune materials, lights, and shader uniforms live.
lil-gui (formerly dat.gui) is a tiny library that builds a live-tweaking panel for any object's properties. Drop it in during dev, expose your shader uniforms / light intensities / material colors as sliders, tune the scene visually rather than typing-and-reload. Removed before production. The old dat.gui is unmaintained; lil-gui is its modern replacement with proper ES module support, smaller bundle, and cleaner API. I use it on every Three.js project for the first 50% of dev work, then bake the chosen values into code and remove the panel. For production tunables that survive ship (admin-only debug mode), I keep it behind a `?debug=true` URL flag.
What this delivers
Concrete output: a working lil gui three js integration on a real production site, not a demo. The integration includes device-tier detection so weak phones get a lighter version automatically. Source files are handed over in their original formats — Blender, GLSL, glTF — so any future developer can continue where I stopped.
How I work with it
On a typical project, lil gui three js ships as a self-contained module: one entry-point JS file, one CSS file, asset bundle below 1.5MB total. I keep the integration sandboxed so the rest of the site stays SEO-friendly classical HTML. Frame budget targets 60 FPS on a mid-range Android, with a measurable fallback below.
Performance budget
Lighthouse mobile target: 85+ across all categories. I measure on real devices, not just emulator. Asset compression: glTF + Draco for meshes, KTX2 for textures, Brotli for shaders. Lazy-load any lil gui three js scene that isn't above the fold so the first paint stays under 1.5s.
When this is overkill
If the goal is a simple e-commerce listing or content blog, a full lil gui three js setup is overkill — a CSS-driven hero plus static images converts just as well at 1/10 the cost. lil gui three js earns its keep when the brand needs a memorable visual moment or when 3D actually clarifies the product (configurators, tours, demos).
Frequently asked questions
Why pick this technology over alternatives?
What if a newer tool comes out next year?
How long does this take?
What does it cost?
What if my visitors are on weak phones?
Ready to ship a 3D experience?
Tell me what you need — fixed price, fixed deadline, no surprises.