WebSim.ai

WebSim.ai is a platform for creating and sharing interactive games and web pages from prompts. Users describe ideas, AI writes the code, and projects can be published for others to play, comment on, and remix. Its early browser simulation supplied the starting point for this broader creation workflow.[2][4][1][3]

WebSim began as a one-day hackathon project inspired by WorldSim, according to Latent Space’s April 27, 2024 account. Rob Haisfield recalled that Karan Malhotra’s WorldSim demonstration inspired him and that Malhotra introduced him to his cofounder at a hackathon. Haisfield described the premise as “what if we simulated a world, but like within a browser instead of a CLI, right?”[1]

The early product used Claude 3 to generate nonexistent webpages from invented URLs; its URL bar also accepted natural-language prompts. Form POST requests were intercepted and answered, while links generated further imagined destinations. Pages could be cached, modified, and regenerated, making navigation itself a way to extend the simulation.[1]

A generated Figma imitation illustrated how users could turn an appearance into working software. In Haisfield’s demonstration, a user named Neil first added rectangles, then addressed disappearing shapes by prompting WebSim to use HTML canvas, script tags, and familiar drawing tools. Haisfield demonstrated drawing and saving an image from the resulting Windows 95-style interface. Shareable browser links let other users open and remix a particular creation.[1]

South Park Commons lists Sean Lee, Rob Haisfield, and Max Bittker as Websim’s founders, and True Ventures and Abstract Ventures as other investors.[2]

In its November 13, 2025 product explanation, Websim positioned itself as a beginner-focused alternative to developer tools such as Cursor, aimed at people learning through prototyping and experimentation. The workflow combined user-supplied ideas and assets with AI-written code. Users could also enable an AI ability to build chatbots, image generators, voice tools, and other interfaces without managing API keys or servers.[4]

Publishing sent projects to a feed where people could like, comment, remix, or gift creators credits. Credits could pay for model use or unlock features in other people’s projects. Multiplayer and remixing made shared experiences part of the platform’s creation process.[4]

The August 21, 2026 update introduced more structured collaboration. Users could offer a remix back through “Suggest to original”; the original creator decided whether to merge it, with the agent pulling in relevant changes. Group building let visitors submit and vote on ideas that the agent would implement. Websim reported that Websim City 2.0 used this workflow and had over 30 contributors.[5]

The same update announced multiplayer continuity during publishing, automatic reconnection, and persistent project roles and permissions configured through the agent. Project agents could read comments, answer questions, and act on bug reports; their replies carried an AI badge. Build mode also gained a premium Websim Max model and support for modern app frameworks without setup.[5]

Websim also announced view-based credit rewards for videos about projects, reporting that one short had recently earned 11,000 credits. That figure described an in-platform reward for a single video.[5]