What it does This Page — instant single-article EPUB Open any article, blog post, or documentation page, click the extension icon, and hit Download EPUB. The extension strips away ads, navigation, and clutter using Mozilla's own Readability engine (the same one behind Firefox Reader View), then packages the clean text into a valid EPUB 3 file. The popup shows the detected title, author byline (when available), approximate word count, and estimated reading time before you download. Build a Book — multi-chapter EPUB Turn a series of web pages into a single book:

On a page that lists links to chapters or articles, select the links with your mouse.
Switch to the Build a book tab and click Import selected links.
The extension fetches and parses each chapter in the background. A check mark appears when a chapter is ready; an × marks pages that could not be parsed.
Reorder chapters with the ↑ / ↓ buttons, or remove any you don't want.
Give the book a title (auto-filled from the first successful chapter), then click Download Book.

Your chapter list and book title are remembered between popup opens, so you can build up a book across multiple browsing sessions. Features

No server, no account — everything runs locally inside Firefox. Your content never leaves your browser.
Images toggle — off by default to keep files small; flip the switch to bundle inline images into the EPUB.
Duplicate detection — importing the same URL twice is a no-op.
State persistence — the chapter list, book title, and image preference survive popup close and browser restart.
Keyboard accessible — the images toggle responds to Space and Enter.

Permissions explained

activeTab — needed to read the content of the page you are currently viewing so Readability can extract the article.
downloads — used to save the generated EPUB file to your Downloads folder.
storage — used to remember your chapter list and preferences between sessions. Nothing is sent anywhere.
\<all_urls> — needed to fetch the HTML of URLs you add as chapters in the multi-chapter mode. The extension only fetches URLs you explicitly select and import.

Supported pages The extension works on any standard HTTP/HTTPS page that contains readable article content. It cannot convert:

about: pages, chrome:// pages, or moz-extension:// pages
Local files opened via file://
Pages that block script injection (the popup will show an error with a suggestion to reload the page)

Libraries used

Mozilla Readability — article extraction (MIT licence, developed by Mozilla)
JSZip — in-browser ZIP/EPUB assembly (MIT licence)

Both libraries run entirely inside the extension and are not loaded from any external server. Privacy This extension does not collect, transmit, or store any personal data. All processing happens locally in your browser. The only network requests made are the page fetches you explicitly trigger when importing chapters.