OpenConstructor offers a free, open-source, no-paywall alternative to v0 and Bolt

A solo developer has launched OpenConstructor, a free, open-source AI website builder that runs entirely in the browser and can be tried without creating an account. In a launch post on dev.to, the developer pitches it as an answer to tools such as v0, Bolt and Framer AI, where a prompt yields a decent page but continued use tends to collide with paywalls, credit counters or exports that are not genuinely usable.

The tool is live at openconstructor.pw, and its source code is published on GitHub under the MIT licence, which means it can also be self-hosted.

How it works

You describe an interface in plain language — the post's example is a landing page for a coffee roastery with a menu and reviews — and watch the AI write the page onto a canvas. Once generated, any block can be selected and adjusted with a follow-up instruction such as "make this darker" or "add a pricing section", and only that block changes.

Usage is free but capped rather than unlimited: three generations per day without an account, and twenty per day with a free one. According to the developer, the built-in AI runs on open models — GPT-OSS 120B and Llama 3.3 70B — served from Cloudflare's free tier, which is why the service can stay free. Anyone who prefers Claude, GPT or Gemini can plug in their own API key, which is stored encrypted on the device.

A hybrid approach to generation

The most technically interesting detail in the post concerns reliability. The developer notes that small free models cannot design consistently, so some page types are assembled from hand-made sections while the AI only produces the content as JSON. That shift reportedly moved output quality from "sometimes nice" to consistently polished.

Beyond generation, the editor ships more than 320 hand-made components — heroes, pricing tables, dashboards, sign-in screens, chat widgets — that can be dropped onto a free-form canvas and mixed with AI-generated blocks. Free templates cover businesses such as coffee shops, SaaS products, restaurants and gyms, and the editor works on phones, with a mobile preview showing exactly what visitors will see.

Publishing and export

Publishing is a single click and produces a free hosted link under the project's own domain, with an optional custom domain, working contact forms that deliver messages by email, view counts, and link previews that render the actual page.

Export is where the project tries hardest to avoid lock-in. Users can download a static HTML site, a ready Vite plus React project, or Vue and Svelte components. For game developers there are also Roblox UI exports in Luau and .rbxmx form, plus LÖVE 2D exports — a combination the developer believes no other builder offers.

Published pages run under a strict content security policy with script-src set to none, meaning nothing on a user-created page can execute JavaScript. Animations and the advertised "cinematic 3D" style — glowing CSS 3D objects and text that lights up on scroll — are pure CSS. The stack itself is deliberately light: a vanilla JavaScript editor, a Cloudflare Worker and Supabase, with no heavy framework.

Caveats

This is a week-old solo project, and every claim above comes from the developer's own announcement rather than independent testing. The developer acknowledges as much, explicitly asking users to report where the AI gets things wrong and what is missing before the tool can be relied on for real projects. Updates are being shipped daily, but the longevity of a free service built on free tiers remains an open question.

Why it matters

The friction OpenConstructor targets is real: the dominant AI site builders gate continued use behind subscriptions or credits, often immediately after the first impressive generation. A browser-based, MIT-licensed tool with genuine code export — and unusual targets like Roblox and LÖVE 2D — drops the entry cost to near zero for anyone experimenting with AI-assisted web design.

The hybrid generation strategy is arguably the broader lesson. Rather than waiting for large models to become cheap, the project routes design decisions through hand-made components and leaves the AI to fill in content. That is a pragmatic template for building reliable products on top of small, open models, and the no-JavaScript publishing model is a sensible security default that other hosted page builders could adopt.