Layouts.dev vs Umwelt

A side-by-side comparison built from both listings. Blank cells mean the company has not given that detail; we never guess.

Layouts.dev compared with Umwelt
Detail	Layouts.dev	Umwelt
What it does	A notebook-style editor for building interfaces with Tailwind	An epistemic state engine that tracks what each character knows, and how they learned it
Stage	MVP	Not given
Founded	Not given	Not given
Based in	Not given	Not given
Pricing model	Freemium	Open source
Pricing	Free: $0/mo (unlimited public projects, 100s of pre-loaded components, pre-loaded asset libraries, AI accelerations, unlimited HTML export). Frontend: $7/mo (35% off when billed yearly, includes everything in Free plus private projects, theming & styling, export to Figma, unlimited React export, liv	AGPL-3.0-only open source license. Commercial license available for closed-source products, services and hosted APIs. Free Play Exception covers free games, mods, interactive fiction and tabletop tools (excluding games with price, in-game purchases, ads, paid content or early access).
Key features	Instant preview and live updates at every keypress One-click deployment Hundreds of pre-loaded components from Radix, shadcn/UI and Layouts UI Built-in asset libraries for illustrations, icons, images and videos AI assistance for generating Tailwind utility classes Export to production-grade HTML and React code NextJS CLI integration for syncing code to projects Real-time visual and code preview on multiple devices Export to Figma (Frontend plan and above) Private projects (Frontend plan and above)	Tracks what each character knows and how they learned it Prevents AI models from leaking story information or twists Records confirmed history that is never deleted Single portable .umw file for entire world state Works across TypeScript, .NET, CLI and any language via JSON protocol Query from any character's point of view at any moment in time Performance of 55-65 microseconds per query with half a million holdings Free Play Exception for non-commercial games and tabletop tools
What makes it different	No setup, deploy, or servers required Simpler, more readable syntax than HTML and React with superpowers Accessible to both designers and developers with minimal learning curve Instant results at every keystroke with live preview on all screens Complete visual development environment with pre-built components eliminating wheel reinvention	Separates world state from character knowledge to prevent narrative leakage Guarantees written down with conformance testing across all clients Idempotent writes ensure consistency across retries Works without AI or can control what AI models are allowed to know Open source with commercial licensing option for closed-source products
Free plan	Not given	Not given
Open source	Not given	Not given
Platforms	Not given	Not given
Public API	Not given	Not given
Community votes	0	0
DR (Domain Rating by Ahrefs)	12 +1 (up) since last check	Not checked yet no change since last check
Trust Flow (Majestic)	9	4
Citation Flow (Majestic)	22	12
Referring domains (Majestic)	134	1

5 details filled in for both companies.

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