wtf is multistack-converter?

MultiStack Converter is a web application that takes old or static website code, such as plain HTML pages or PHP templates, and converts it into modern, component based code ready for frameworks like React, Next.js, or Astro. It uses Google's Gemini AI model to understand the uploaded code and rewrite it into typed, responsive components rather than doing a simple find and replace. A user can drag and drop a single file or a whole zip archive containing HTML, PHP, Astro, or React source files. The tool then lets them choose a target setup to export to, including a Vite based React app, a Next.js 15 project with its full folder structure, an Astro project, or a Create React App style project. Converted styling can come out as Tailwind CSS, CSS Modules, or Styled Components, depending on what the user picks. The interface includes a file explorer that highlights the components it identified, a side by side preview showing the converted result rendered live, and a code editor panel with several syntax highlighting themes to choose from. Once conversion is done, the tool bundles the entire generated project, including assets and folders, into a zip file the user can download directly from the browser using a JavaScript library called JSZip, without needing a server round trip for that step. To run the project, a user needs Node.js and a Google Gemini API key, which they add to a local environment file before starting the development server. The README states that code conversions happen server side and that API keys are never exposed to the browser. The project is open source under the MIT license, and the author invites others to fork it and contribute.