Open-source AI website builders exist in 2026, but most of the ones with AI built in are app builders in the Bolt or Lovable mold that you run yourself on your own model API key, not builders made for marketing sites. The safest bets are bolt.diy (MIT) and Dyad (mostly Apache 2.0), while open-source visual website builders such as Webstudio and Silex get their AI through MCP, from an agent you bring. Whichever you pick, read the actual license file and budget for API keys, sandboxes, hosting and upkeep.
If the license doesn't matter and you just want the right tool, start with our comparison of the best AI website builders, which covers hosted options too.
Four kinds of "open-source AI builder"
The label covers four different things:
- Prompt-to-app builders you run yourself. An agent writes and runs the code on your own model key. Most aim at web apps.
- Visual builders where the AI comes from outside. Open editors in the Webflow mold, where AI arrives through an MCP server or a paid cloud service.
- Page generators. A prompt or screenshot in, one page or component of front-end code out.
- Frameworks and starters. Code you build your own builder or app on.
Our guide to AI app builders versus AI website builders explains why that split matters.
The map
Dates are each project's last commit on GitHub, checked October 15, 2026. "Your own key" means your own model key or AI agent.
| Project | License | What it builds | Your own key? | Active in 2026? |
|---|---|---|---|---|
| bolt.diy | MIT | Full-stack web apps and sites | Yes, 22+ providers incl. local | Yes (Oct 14) |
| Dyad | Apache 2.0 + FSL (src/pro) | Web apps | Yes | Yes (Oct 14) |
| Quests | Apache 2.0 | Full-stack apps (desktop) | Yes, 20+ providers | Quiet since Apr 7 |
| sandboxd | MIT | Web apps, one container each | Yes | Yes (Oct 12) |
| Tinykit | MIT | Web apps (early alpha) | Yes | Likely stalled (Jan 9) |
| OpenThorn | "MIT" in README only, no LICENSE file | Websites and apps | Yes, 12 providers | Quiet since Aug 31 |
| Llama Coder | MIT | Small one-prompt apps | Together AI key only | Yes (Sep 15) |
| Open Lovable | MIT | React apps, site recreations | Yes, plus Firecrawl and sandbox keys | Barely (2 commits, Oct 9) |
| Chef | Apache 2.0 | Full-stack apps on Convex | Yes | Barely (3 commits, Mar 13) |
| Puter AI Builder | Apache 2.0 | Websites and apps | No, uses Puter's services | Yes (new; Oct 14) |
| Libra AI | AGPL-3.0 | Web apps on Cloudflare | Yes | No (Sep 24, 2025) |
| Webstudio | AGPL-3.0 core, one proprietary package | Websites | Your own agent, via MCP | Yes (Oct 14) |
| Silex | AGPL-3.0 | Static websites | Your own agent, via MCP | Yes (Oct 9) |
| Plasmic | MIT + AGPL-3.0 (platform/) | Websites and apps | Yes, self-hosted copilot | Yes (Oct 14) |
| ChaiBuilder Core | BSD-3-Clause | Next.js websites | Yes | Yes (Sep 21) |
| Onlook | Apache 2.0 | Next.js + Tailwind sites and apps | Yes (OpenRouter) | Barely (6 commits, Jul 22) |
| ToolJet | AGPL-3.0 | Internal tools | Partly, via MCP | Yes (Oct 14) |
| screenshot-to-code | MIT | Single pages, prototypes | Yes | Yes (Oct 9) |
| OpenUI | Apache 2.0 | UI components, single pages | Yes, or local Ollama | Maintenance only (Jun 30) |
| Fragments | Apache 2.0 | AI-generated apps (template) | Yes, plus an E2B key | Yes (Oct 13) |
| Reflex | Apache 2.0 | Python web apps (framework) | No built-in AI | Yes (Oct 14) |
| Puck | MIT | Pages inside your React app | No, AI runs on Puck's cloud | Yes (Oct 14) |
| GrapesJS | BSD-3-Clause | HTML templates and emails | No AI in the core | Yes (Oct 13) |
GPT Pilot is missing on purpose; see the warning below.
Prompt-to-app builders you run yourself
bolt.diy and Dyad: the safest bets
bolt.diy is the open-source, community-run version of Bolt. You prompt, run, edit and deploy full-stack web apps in the browser, choosing the model per prompt, including local ones through Ollama. It runs with pnpm, Docker or an Electron desktop app, and exports a ZIP, pushes to Git, or deploys to Netlify, Vercel or GitHub Pages. Two notes: its README says the WebContainers API it uses has separate commercial terms for enterprise deployment, and the original bolt.new repository hasn't been updated since December 2024.
Dyad is a desktop app for Mac and Windows with no sign-up and bring-your-own keys, positioned as a local alternative to Lovable, v0 and Bolt. Everything is Apache 2.0 except the src/pro folder, which uses the Functional Source License.
The rest, with their catches
- OpenThorn is one of the few aimed at websites: an agent writes the code, previews it in the browser and deploys to Cloudflare Pages, with full code export. It's small and new, stores your keys encrypted server-side, and self-hosting needs Supabase, a Cloudflare API token and Vercel functions.
- Quests is a desktop builder with exportable apps, but no commits since April 7.
- sandboxd is the engine behind a builder: a Go program on Docker that runs a coding agent such as OpenCode in isolated containers and serves each app at a live preview URL.
- Llama Coder accepts a Together AI key only, and needs Postgres and S3 to self-host.
- Open Lovable, Firecrawl's example app, needs Firecrawl, model and sandbox keys; its README points to Lovable for a complete cloud product.
- Chef, Convex's fork of bolt.diy, still uses Convex's hosted control plane when run locally.
- Puter AI Builder is new and busy, but its AI, storage, database and hosting come from Puter's platform.
- Tinykit and Libra AI have gone quiet.
Visual builders where the AI comes from outside
For a website rather than an app, this group is closer, but the AI usually isn't in the box.
- Webstudio is an open-source Webflow alternative you can self-host and connect to any headless CMS. There's no built-in AI chat; its CLI runs an MCP server with connect commands for Codex, Cursor and VS Code, so you drive it with the agent you already pay for. (Model Context Protocol is the open standard that lets an AI assistant use another tool.)
- Silex builds static websites visually. Its AI comes through an MCP server in the Silex Desktop app, still in alpha, so you can use local Ollama models, OpenCode or Goose.
- Plasmic plugs into your React or Next.js codebase. Its README doesn't advertise AI, but the platform includes a copilot that reads model API keys from server secrets.
- ChaiBuilder Core is a block-based builder you install inside your own Next.js App Router app, with AI through the Vercel AI SDK. It's the closest thing here to an AI editor for Next.js sites, and it's a developer's tool.
- Onlook, a visual editor for Next.js and Tailwind projects, saw mostly docs commits in 2026; the company's next product is hosted.
- ToolJet builds internal tools. Its built-in AI is Enterprise, but its beta MCP server lets your own agent build apps on your subscription.
Page generators and frameworks
screenshot-to-code turns screenshots, mockups, Figma designs and screen recordings into HTML with Tailwind or CSS, React, Vue and more. OpenUI, which Weights & Biases calls a less polished open-source v0, is in maintenance.
Fragments is E2B's Next.js starter for AI-generated apps run in sandboxes. Reflex is a Python framework; its AI Builder is linked from the README, but we found no source for it in Reflex's GitHub organization, so treat it as hosted. Puck and GrapesJS are editors you embed in your own app: Puck's AI runs on Puck's cloud, and GrapesJS's README steers you to its commercial Studio SDK.
A warning about GPT Pilot
GPT Pilot, the engine behind Pythagora, still appears on older lists. Don't use it. Its README says the repository is no longer maintained, and that a credential-stealing supply-chain worm hidden in core/telemetry/ from August 2025 until June 11, 2026 was found and removed. Its only 2026 commits are that cleanup, and its license (FSL) is source-available, not open source. If you ran it in that window, treat any keys it could reach as exposed and rotate them. Don't confuse it with gpt-engineer, a separate MIT-licensed project that is now archived.
Licenses in plain words
General information, not legal advice; how licenses are applied varies by country.
- MIT, BSD-3-Clause and Apache 2.0 are permissive: use, change and sell the code, even inside a closed product, as long as you keep the notices.
- AGPL-3.0 is copyleft that reaches network use. If you modify an AGPL builder and let others use your version over the internet, you must offer them your modified source. That matters if you'd offer a modified Webstudio, Silex or ToolJet as a service to others.
- FSL (Functional Source License) is source-available: you can read and run the code, but not build a competing commercial product, and each release converts to Apache 2.0 or MIT after two years.
Then check what the GitHub sidebar won't tell you:
- Open the LICENSE file. GitHub labels Dyad, GrapesJS and GPT Pilot "Other"; the files say Apache 2.0 plus FSL, plain BSD-3-Clause, and FSL.
- Look for parts with their own terms. Dyad's src/pro, Plasmic's platform/ (AGPL), Webstudio's proprietary animation package and bolt.diy's WebContainers dependency.
- Check that a license exists. OpenThorn says MIT in its README, but has no LICENSE file and GitHub detects none. Code without a clear license generally falls back to ordinary copyright, so ask for one before you build on it.
- Find where the AI lives. Puck AI runs on Puck's cloud, ToolJet AI is an Enterprise feature, and Puter's builder depends on Puter's services.
What self-hosting actually costs
The code costs nothing to download. Running it does.
- Model usage. Every prompt is billed to your own key. Local models through Ollama (bolt.diy, Quests, OpenUI, Fragments) avoid that but need a capable machine.
- Extra accounts. E2B for Fragments, a sandbox plus Firecrawl for Open Lovable, CodeSandbox for Onlook, Postgres and S3 for Llama Coder. Each has its own terms.
- A backend. Supabase for Onlook and OpenThorn, a stack of Cloudflare services for Libra AI. Desktop apps like Dyad and Quests skip the server.
- Hosting the output. The builder and the sites it makes are separate deployments.
- Maintenance. Updates, security fixes, and keys on a server you now look after. When maintainers stop, you inherit the code.
Fine for a developer who wants control; a lot to own for a business that just needs a website. If cost is your real reason for looking, also compare the free AI website builders.
Where FNJ fits, and why it isn't open source
FNJ is not open source. It's a paid AI website builder, and FNJ runs the AI, so there's no API key, sandbox or builder server to manage.
What it shares with open source is what many people actually want from it: no lock-in. When your site is ready, you download a Next.js App Router project or static HTML, or push it to a branch of your own GitHub repository. There's no FNJ runtime, script or badge in the code; you host the HTML on Cloudflare Pages or any static host, or the Next.js project on a host that runs Next.js such as Vercel or Netlify, and it keeps working if you stop using FNJ. That's what AI website builder code export means here, and our guide to website builder lock-in covers what to check in any tool.
It's the wrong tool for an app: FNJ builds marketing websites, with no forms, log-ins, databases, store checkout or blog engine.
Open source or owned code?
Open source gives you the builder's code, not a finished website, and the bill moves to your API keys, sandboxes and time. If you want a marketing site whose code you own without running any of that, see how FNJ compares in our guide to the best AI website builders.
Frequently asked questions
Is there an open-source version of Bolt or Lovable?
bolt.diy is the open-source, community-run version of Bolt, MIT-licensed and still updated in October 2026. Dyad is a desktop app positioned as an alternative to Lovable, v0 and Bolt, mostly Apache 2.0 with one source-available folder.
Are open-source AI website builders free?
The code costs nothing under its license, but running it usually doesn't: you pay your model provider per prompt, plus any sandbox, database or hosting service the project needs.
Can I self-host an AI website builder without an API key?
Mostly no; nearly every self-hosted AI builder expects a model key or your own AI agent. The exceptions are local models through Ollama, which bolt.diy, Quests, OpenUI and Fragments support, and Puter AI Builder, which uses Puter's platform services instead.
Is FNJ open source?
No. FNJ is a paid AI website builder that runs the AI for you. The sites it builds export as a Next.js project or static HTML with no FNJ runtime, so you own the code and host it yourself.
Which licenses count as open source?
MIT, BSD-3-Clause, Apache 2.0 and AGPL-3.0 are all approved by the Open Source Initiative. The Functional Source License is source-available rather than open source, and a README that names a license without a LICENSE file is a weak basis to build on.