: A powerful, modern choice that works in both Node.js and the browser. It automatically handles the fetching of images and fonts, which is often the most tedious part of the process.

: Fetch your blog articles. You can use a tool like JSZip to start bundling files together.

If you're not looking to write a custom script today, there are excellent existing tools to bridge the gap: Generating an EPUB File in the Browser - Jim Nielsen's Blog

: This library uses a "template" approach, gutting a sample EPUB and refitting it with your specific content and metadata.

If you're building your own script, here is the general logic used by most open-source tools:

: Let users "download as eBook" without needing a backend.

: Every EPUB needs a container.xml and an .opf file to tell the reader where the chapters are and who wrote the book. Libraries like @smoores/epub for Node.js are built specifically to manage these requirements. Beyond Coding: No-Code Alternatives

: While primarily a world-class reader for displaying EPUBs in a browser, it is the industry standard for interacting with eBook data via JavaScript. The 3-Step Conversion Workflow