The short answer: three open-source projects do what Base44, Lovable and Bolt.new do, turning a chat into a running web app. Dyad is a desktop app for Mac and Windows and is the closest to a hosted builder. bolt.diy, from the StackBlitz Labs GitHub organisation, is an open-source Bolt-style workspace that runs in your browser from your own machine or server. Open Lovable is a small example app from Firecrawl for developers. All three are free to download; you pay your AI model provider for every prompt instead of paying the builder a subscription, and you host the result yourself.
None of them replaces the managed backend that Base44 includes. If what you want from “open source” is a portable database, the faster fix is a hosted builder on standard Postgres; see Lovable Cloud vs Supabase and lock-in and export.
The three compared
Read from each project’s README, LICENSE and package.json on GitHub, 2 November 2026.
| Attribute | Dyad | bolt.diy | Open Lovable |
|---|---|---|---|
| What it is | Desktop AI app builder, “like Lovable, v0, or Bolt, but running right on your machine” | Open-source AI developer workspace that builds full-stack apps in the browser | Example app from the Firecrawl team: chat to build React apps |
| Where it runs | Installed app, Mac or Windows; no sign-up | Local dev server (pnpm run dev), Docker, or an Electron desktop build for Windows, macOS and Linux | Next.js app you clone and run locally (localhost:3000) |
| Licence | Apache 2.0, except code under src/pro (Functional Source License 1.1) | MIT; uses the WebContainers API, which has separate commercial terms for enterprise use | MIT |
| AI models | Bring your own API keys | 22+ providers, including Anthropic, OpenAI, Google, DeepSeek, Groq, and local models through Ollama or LM Studio | Gemini, Anthropic, OpenAI or Groq key |
| Other keys required | None listed | None beyond a model provider | Firecrawl API key (required) and a sandbox: Vercel (default) or E2B |
| Backend and deploy | Not covered in the README | Supabase integration; one-click deploy to Netlify, Vercel and GitHub Pages; Git push and ZIP export | Runs generated apps in the sandbox; deployment not covered in the README |
| Project status | Main branch at version 1.22.0-beta.1; no maintenance notice in the README | Maintenance: the README says ongoing work is bug fixes and dependency updates, with “no new features” planned | Version 0.1.0; the README points to Lovable.dev “for a complete cloud solution” |
Sources: Dyad, bolt.diy, Open Lovable, each read 2 November 2026. Version numbers come from each repository’s package.json on that date.
What you pay instead of a subscription
The projects are free; the model calls are not. Every prompt goes to the provider whose key you added and is billed at that provider’s API rates, so a long build session costs what the tokens cost. Hosted builders bundle that cost into a plan:
| Hosted builder | Entry paid plan | What it includes |
|---|---|---|
| Base44 | Starter, $20 a month ($16 billed yearly) | 100 message credits and 2,000 integration credits a month, plus the managed database, auth and hosting |
| Lovable | Pro, $25 a month ($21 billed yearly) | 100 credits a month plus 5 daily build credits and hosting (Lovable’s Cloud and AI grants were documented as temporary through 31 Oct 2026; re-check) |
| Bolt.new | Pro, $25 a month | From 10M tokens a month, hosting up to 1M web requests |
Hosted prices are from each vendor’s pricing page via our pricing index, checked 29 September 2026. We have not measured how many tokens a typical Dyad or bolt.diy build uses, so this page does not claim the open-source route is cheaper. It is cheaper when your own token spend for a month is lower than the plan price, and it puts no credit ceiling on a session, which is also how it can cost more.
Two costs the hosted plans include and the open-source route does not: hosting the finished app (see custom domains and hosting and Cloudflare Pages for a Vite app), and a backend for data and logins (see connecting Supabase to any builder).
Pick by situation
| Your situation | Pick |
|---|---|
| You want a Lovable-style builder on your own laptop, with no account | Dyad |
| You want to choose a different model per prompt, including a local one | bolt.diy |
| You already have a Firecrawl key and want a small codebase to read and modify | Open Lovable |
| You want a project that is still adding features | Dyad or Open Lovable; bolt.diy’s README says no new features are planned |
| You want a managed database, auth and hosting without setup | Stay hosted: Base44 or Lovable |
| You can code and want an agent inside your own repository | An open-source coding agent instead: Cline or Aider |
The last row matters. If the reason you want open source is control over the code, an open-source coding agent working on a normal repository gives you that more directly than an open-source builder does. Both Cline and Aider are free and bill through your own API key.
Method
Researched from each project’s public repository on GitHub (README, LICENSE and package.json), read 2 November 2026, and from our pricing index for the hosted plans (vendor pricing pages, 29 September 2026). We have not installed or built an app with Dyad, bolt.diy or Open Lovable, so this page makes no claim about output quality or speed. Repositories change quickly; check the README and licence before you rely on a feature.
Common questions
Is there an open-source version of Base44?
Not that we could find: Base44 is a hosted, closed product, and we found no open-source release of its builder. The closest open-source projects are Dyad, bolt.diy and Open Lovable, none of which includes a managed backend like Base44’s. For hosted options, see Base44 alternatives.
Is Dyad free?
The app is free to download and the core is Apache 2.0. You pay your AI provider for model usage through your own key. Code in the src/pro folder is under the Functional Source License, which is free to use but not to resell as a competing product.
Is bolt.diy the same as Bolt.new?
bolt.diy lives under the StackBlitz Labs organisation on GitHub and is MIT-licensed; Bolt.new is the hosted product with plans, hosting and its own token allowance. bolt.diy lets you pick the model provider, and its README says it is now in maintenance. See our Bolt.new review.
Do I need to code to use an open-source app builder?
Dyad installs like a normal desktop app. bolt.diy and Open Lovable need Node.js and a terminal to set up, and Open Lovable needs several API keys. Without any coding, a hosted builder from our best free AI app builder list is the easier start.