Save a web page/selection as an eBook (.epub format) - a Chrome/Firefox/Opera Web Extension
JavaScript
1,129
185 commits
updated Sep 1, 2026
Save a web page/selection as an eBook (.epub format) - a Chrome/Firefox Web Extension
or manually
1. Navigate to chrome://extensions/
2. Load unpacked extension ...
3. Select the extension's directory
or manually
1. Navigate to about:debugging
2. Load temporary add-on ...
3. Select the extension's directory
| Keep the page's colours and fonts | Carries the page's own look into the book (colours, fonts, borders, lists, alignment), so code, tables and pull quotes still look like they did. Off, the book is plain text laid out by the reading system. |
| Apply Readability.js | Keeps only the article, dropping navigation, sidebars and comments. Applies to Save Page and Add Page as Chapter only; pages that are not articles are saved whole. |
| Review Before Saving | Opens Save Page and Save Selection in the chapter editor instead of downloading straight away, so the book can be previewed, edited and described first. The editor's Generate button saves the file. |
| Style Library ... | Opens the library of CSS applied to pages while they are captured, so what is saved is the page without its banners and sidebars. The line beneath the button lists the styles the current page would take. |
| Capture this page first | Takes a copy of the current page for the library to preview against, which also allows picking an element by clicking it. This is a capture, so it takes as long as saving does. Clear it to open the library straight away on the last page captured. |
| Save Page | Saves the whole page as a one-chapter eBook. |
| Save Selection | Saves only what is selected on the page as a one-chapter eBook. |
| Add Page as Chapter | Appends the whole page to the book being collected, without downloading anything yet. |
| Add Selection as Chapter | Appends only the selection to the book being collected. |
| Edit Chapters ... | Opens the chapter editor with everything collected so far: reorder, rename, edit and style the chapters, set the book's details, then generate the .epub. |
These two make a book on their own, of one chapter, rather than adding to the book being collected. Each of them starts a new book, so anything gathered with Add Page as Chapter or Add Selection as Chapter and not yet generated is discarded when one of them runs.
Save Page takes the page you are on, in full. If Apply Readability.js is on, only the article is kept and the navigation, sidebars and comments are dropped; on a page that is not an article the whole page is saved and you are told that is what happened.
Save Selection takes only what is selected on the page, so make the selection first: with nothing selected the save stops and says the selection is empty. Readability.js is not applied here, because a selection is already you saying what the content is.
Both of them capture the page through whatever styles the Style Library has switched on for that address, and both carry the page's own colours and fonts into the book if Keep the page's colours and fonts is ticked.
Without Review Before Saving, the .epub is built and downloaded as soon as
the page has been read, with no further questions. The file is named after the
page's title, or eBook.epub if the page has no title. Nothing is kept
afterwards, so the next save starts from a clean sheet.
With Review Before Saving, nothing is downloaded. The chapter is opened in the chapter editor in a new tab, where you can:
The Generate button in the editor is what writes the file. The book is already named after the page, so a review you make no changes to produces the same file the immediate save would have. Close the tab without generating and the chapter stays where it is: Edit Chapters ... opens it again, and Add Page as Chapter appends to it.
The keyboard shortcuts for saving a page and a selection go the same way, so they follow this setting too.
These three build a book out of several pages. Add Page as Chapter and Add Selection as Chapter put one page, or one selection, at the end of the book being collected and tell you it went in. Nothing is downloaded and no window opens, so you can walk through a series of articles, adding each as you go. Both read the page the same way Save Page and Save Selection do: the styles the Style Library has switched on for the address are applied first, Keep the page's colours and fonts decides whether the page's own look comes with it, and Apply Readability.js narrows a page to its article but leaves a selection alone. Adding with nothing selected stops and says the selection is empty.
The chapters wait in the extension, not in a file. They survive closing the tab and closing the browser, and they stay there until you generate the book, remove them, or run Save Page or Save Selection, which start a new book and discard what was collected.
Edit Chapters ... opens all of it in a tab of its own. It is the same editor Review Before Saving opens, holding a whole book rather than one page.
| eBook Title | What the book is called, and what the file is named after. Left empty, the book is called eBook. |
| eBook Stylesheet | Folded away until you open it. CSS for the whole book, every chapter of it. Not the same as the Style Library, which cleans up pages on the way in. |
| eBook Details | Also folded away. Authors, language, publisher, date and description for the book. A field left empty shows in grey what would be taken from the chapters instead, which is what will be used. |
| The chapter rows | One per chapter, in the order they will be bound. Drag the handle on the left to reorder them, and type in the box to rename one, which renames it in the table of contents. |
| Preview | Opens that chapter on its own, to read it, edit it, style it and describe it. See The Preview dialog. |
| Remove | Takes one chapter out, after asking. It goes when the changes are saved. |
| Cancel | Closes the tab and keeps everything as it was when it opened. |
| Remove Chapters | Throws away the whole collection, after asking: the chapters, the title, the stylesheet and the details. |
| Save changes | Writes the order, the names, the title, the stylesheet and the details, says so, and closes the tab. The chapters stay where they are, ready to be added to. |
| Generate eBook ... | Saves all of that and then builds the .epub and downloads it. An empty book is refused. |
Generating does not empty the collection. The chapters are still there afterwards, so a book can be generated, read, then corrected and generated again. Use Remove Chapters when you want to start the next one from nothing.
Every chapter row in the editor has a Preview button, which opens the chapter over the list. The page it shows is built by the same code that writes the book, so what you are looking at is the chapter as it will be packaged. Pagination, fonts and margins are not in it: those belong to the reading system and differ between devices.
The dialog is also where a chapter is edited, and the rendering is the editing surface, so what you remove is the thing you saw. The toolbar shows only the buttons the current mode can use, and the line under it says what the mode does and, while removing, names the element a click is about to take.
| X | Closes the dialog. Content edits, chapter CSS and chapter details all live in the dialog until they are saved, so if any of them are unsaved you are asked before they go. Escape and a click on the background outside the dialog do the same thing. |
| View | Reading mode, where nothing can be changed by accident. Clicks on links inside the chapter go nowhere. |
| Remove elements | The element under the pointer is outlined, and clicking it takes it out of the chapter. Pictures that nothing points at any more are dropped from the book as well, so removing an image also removes its weight. |
| Select parent | Widens what a click would take, one level up at a time, from a paragraph to the figure or the block around it. Arrow Up does the same. It stops at the outermost element that is yours to remove. |
| Select child | Narrows it back down one level. Arrow Down does the same. Off until you have widened something. |
| Edit text | Makes the chapter editable, so you can click into it and type. Pasting and dropping insert plain text only, because markup from somewhere else would pull in that site's images and would not survive saving anyway. The chapter's title is not edited here, it is edited in the chapter list. |
| Add paragraph before | Puts an empty paragraph in front of the block the cursor is in, or at the very start of the chapter if the cursor is nowhere. It arrives holding the words "New paragraph", selected, so typing replaces them. |
| Add paragraph after | The same, on the other side of that block, or at the end of the chapter. |
| Chapter CSS | Opens a box of CSS for this one chapter, applied after the styles captured from its page. The preview redraws as you type. This is the exception for a single chapter; the stylesheet for the whole book is in the editor behind the dialog. |
| Chapter details | Opens what this chapter says about itself: title, authors, language, publisher, date and description. A field left empty shows what the page said in grey, which is what will be used. Language is the one field a reading system acts on chapter by chapter. |
| Undo | Steps back one change, up to thirty of them. A run of typing counts as one step rather than one character. Ctrl+Z, or Cmd+Z, does the same. |
| Save chapter | Writes the edited content, the chapter CSS and the chapter details onto the chapter. It stays greyed out until there is something to write. Nothing else in the dialog saves anything, so closing without pressing it throws the work away. |
Saving a chapter puts it back in the list. The book itself is still not written until Generate in the editor.
The Style Library holds CSS that is applied while a page is captured. Use it to remove cookie notices, menus, ads, sidebars, comments, and other content that should not enter the EPUB.
This differs from the eBook Stylesheet in the chapter editor:
The extension includes nineteen capture styles. Some apply to particular sites. Others can apply to every page. You can enable them, edit them, duplicate them, or create your own.
To make a style for the current page:
Clear Capture this page first to open the library with its last captured page. This is faster when you do not need a new preview.
A style can apply to every captured page or to addresses matched by domain, URL prefix, glob, or regular expression. The library also supports JSON import and export.
Remote url() and @import references are removed from imported CSS. This
prevents an imported style from contacting another site during capture.
Three panels, left to right: the library, the style being edited, and the page they are tried on.
The library, on the left
| Search name, pattern or CSS | Narrows the list by what you type, looking inside the CSS as well as at the names, so a style can be found by the selector it hides. |
| All, Applies here, Site styles, Every page, On | Filters for, in order: everything; only what covers the page in the preview; only styles tied to a pattern; only styles applied to every capture; only what is switched on. |
| Mine, Built-in | Splits the list by where a style came from: written or imported by you, or shipped with the extension. |
| The checkbox on each row | Switches that style on or off. Off means it exists but is not applied to anything. |
| The row itself | Click to open the style in the middle panel. Underneath the name it says where the style applies, and a badge on the right says Built-in, Edited built-in, Imported or Yours. |
| New site style | Starts a style tied to a pattern, for one site or one part of one. |
| New every-page style | Starts a style applied to every page captured, whatever the address. |
| Import ... | Opens a style file, or takes one pasted in. It says what would be added and what already exists under the same name before writing anything, so a clash can be kept as a separate copy or written over. |
| Export all | Writes the whole library to a JSON file. |
The style, in the middle
| The badge, Duplicate, Export | The badge says where this style came from. Duplicate makes a copy to change freely, which is the way to keep a built-in as it is while trying something else. Export writes this one style to a file. A built-in you have edited also gets Reset to built-in, which puts the shipped version back. |
| Name | What the style is called in the list. |
| Note | A line to yourself about what the style is for. |
| Applies to | Either every page that is captured, or pages matching a pattern. Choosing the pattern reveals how to match (by domain, by address prefix, by a * glob, or by a regular expression), a box for the pattern, and a box holding an address to test it against, which says as you type whether that address matches. |
| CSS | The rules themselves, applied to the page while it is captured, not to the eBook. |
| Hide images, Hide sidebars, Unstick headers, Hide comments, Single column, Bigger text | Ready-made rules, written into the CSS box at a click, to be kept or changed. |
| Remove Style, Save Style | At the foot of the window. Remove asks first. Nothing is applied to a capture until it is saved. |
The preview, on the right
The preview shows a copy of a real page, rendered the way the eBook will show it, with the styles above applied as you type them. Above it, the address it was taken from, and the styles it is showing, listed in the order they were applied.
| Pick element | Point at something in the preview and click it to write the rule that hides it into the style you have open. The line underneath says what the click would hide, and how many elements on the page that rule covers, before you click. |
| Select parent, Select child | Move the pick outwards to the box around what you are pointing at, or back inwards, when the thing you want is not what sits under the cursor. |
| Discard | Throws away the captured page, leaving the library with nothing to preview against. |
The page comes from the popup's Capture this page first checkbox, which is ticked by default unless the page has already been captured. Capturing takes as long as saving the page does, so leave the box clear to open the library straight away on the last page captured. Fonts, margins and pagination are not part of the preview: those belong to the reading system.
Remote url() and @import references are removed from imported CSS: they
would fetch a file from another site every time you saved a page, which tells
that site what you are reading.
sudo apt-get install calibre
ebook-convert "book.epub" "book.mobi"
NOTE These shortcuts are not fixed and the browser will assign a different shortcut if the default one is taken
| Shortcut | Description |
|---|---|
| Alt + Shift + 1 | Save current page as eBook |
| Alt + Shift + 2 | Save current selection as eBook |
| Alt + Shift + 3 | Add current page as chapter |
| Alt + Shift + 4 | Add current selection as chapter |
in Chrome:
1. Navigate to chrome://extensions/
2. Scroll down
3. Click on Keyboard shortcuts
<picture>, srcset, and common lazy loaded images more reliably, including pages that use placeholder pixels.image-set(), imports, and other disguised remote references.images/ directory in text only books, eliminating the associated EPUBCheck warning.Some pages carry things a book should not: a sidebar, a cookie banner, a header that reappears in the middle of a chapter. The old custom style editor was a bare text box where the CSS had to be written by hand. It is a proper library now.
A new option in the popup. With it on, Save Page opens the chapter in an editor instead of downloading straight away, so things can be fixed before the book is made:
The tests are in tests/, and they run the code in web-extension/ rather than
a copy of it.
Node.js. There is nothing to install, the tests have no npm or yarn dependencies.
Google Chrome or Chromium, for the DOM tests. Those need a real browser,
because the extraction code uses getComputedStyle, layout measurements,
canvas.toDataURL and the HTML5 parser behind <template>. Chrome is found
automatically on macOS, and through google-chrome or chromium on PATH.
Otherwise set CHROME=/path/to/chrome.
EPUBCheck, to validate a generated book. Install it with
brew install epubcheck, or download a
release and set
EPUBCHECK_JAR=/path/to/epubcheck.jar, which also needs java on PATH.
When Chrome or EPUBCheck is missing, the steps that need them print SKIP and
everything else still runs.
cd tests
./run-all.sh
It prints a section per stage. It ends with ALL PASSED and exit code 0, or
with a list of the failures and exit code 1. A full run takes a couple of
minutes. The books it builds are written to tests/out/, which is git ignored,
so you can open them in a reader afterwards.
cd tests
./run-dom-tests.sh # every fixture in tests/dom/, in headless Chrome
node utils.js # pure helper functions
node style-library.js # style matching, and the v1 custom style migration
node background.js # background jobs and message state
node outline.js # chapter outline and navigation tree
node epub-builder.js # EPUB builder scenarios
# build a book with the extension's own saveEbook.js, then check it
node build-epub.js out/fixture.epub # a book of several chapters
node build-epub.js out/single.epub --single # a one chapter book
node check-epub.js out/fixture.epub # structural checks, no JVM needed
./run-epubcheck.sh out/fixture.epub # the official validator
# build a book out of chapters edited in the chapter editor, then validate it
./build-edited-epub.sh
# check that each test in check-epub.js rejects a broken archive
node check-epub-negative.js out/fixture.epub
To run one DOM fixture instead of all of them, open it in a browser, for example
tests/dom/mathml.html, and read the PASS and FAIL lines it renders.
check-epub.js and check-epub-negative.js need a book to inspect, so run the
matching build-epub.js first. run-epubcheck.sh builds one itself when the
file is not there.
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Save a web page/selection as an eBook (.epub format) - a Chrome/Firefox/Opera Web Extension
JavaScript
1,129
185 commits
updated Sep 1, 2026
Save a web page/selection as an eBook (.epub format) - a Chrome/Firefox Web Extension
or manually
1. Navigate to chrome://extensions/
2. Load unpacked extension ...
3. Select the extension's directory
or manually
1. Navigate to about:debugging
2. Load temporary add-on ...
3. Select the extension's directory
| Keep the page's colours and fonts | Carries the page's own look into the book (colours, fonts, borders, lists, alignment), so code, tables and pull quotes still look like they did. Off, the book is plain text laid out by the reading system. |
| Apply Readability.js | Keeps only the article, dropping navigation, sidebars and comments. Applies to Save Page and Add Page as Chapter only; pages that are not articles are saved whole. |
| Review Before Saving | Opens Save Page and Save Selection in the chapter editor instead of downloading straight away, so the book can be previewed, edited and described first. The editor's Generate button saves the file. |
| Style Library ... | Opens the library of CSS applied to pages while they are captured, so what is saved is the page without its banners and sidebars. The line beneath the button lists the styles the current page would take. |
| Capture this page first | Takes a copy of the current page for the library to preview against, which also allows picking an element by clicking it. This is a capture, so it takes as long as saving does. Clear it to open the library straight away on the last page captured. |
| Save Page | Saves the whole page as a one-chapter eBook. |
| Save Selection | Saves only what is selected on the page as a one-chapter eBook. |
| Add Page as Chapter | Appends the whole page to the book being collected, without downloading anything yet. |
| Add Selection as Chapter | Appends only the selection to the book being collected. |
| Edit Chapters ... | Opens the chapter editor with everything collected so far: reorder, rename, edit and style the chapters, set the book's details, then generate the .epub. |
These two make a book on their own, of one chapter, rather than adding to the book being collected. Each of them starts a new book, so anything gathered with Add Page as Chapter or Add Selection as Chapter and not yet generated is discarded when one of them runs.
Save Page takes the page you are on, in full. If Apply Readability.js is on, only the article is kept and the navigation, sidebars and comments are dropped; on a page that is not an article the whole page is saved and you are told that is what happened.
Save Selection takes only what is selected on the page, so make the selection first: with nothing selected the save stops and says the selection is empty. Readability.js is not applied here, because a selection is already you saying what the content is.
Both of them capture the page through whatever styles the Style Library has switched on for that address, and both carry the page's own colours and fonts into the book if Keep the page's colours and fonts is ticked.
Without Review Before Saving, the .epub is built and downloaded as soon as
the page has been read, with no further questions. The file is named after the
page's title, or eBook.epub if the page has no title. Nothing is kept
afterwards, so the next save starts from a clean sheet.
With Review Before Saving, nothing is downloaded. The chapter is opened in the chapter editor in a new tab, where you can:
The Generate button in the editor is what writes the file. The book is already named after the page, so a review you make no changes to produces the same file the immediate save would have. Close the tab without generating and the chapter stays where it is: Edit Chapters ... opens it again, and Add Page as Chapter appends to it.
The keyboard shortcuts for saving a page and a selection go the same way, so they follow this setting too.
These three build a book out of several pages. Add Page as Chapter and Add Selection as Chapter put one page, or one selection, at the end of the book being collected and tell you it went in. Nothing is downloaded and no window opens, so you can walk through a series of articles, adding each as you go. Both read the page the same way Save Page and Save Selection do: the styles the Style Library has switched on for the address are applied first, Keep the page's colours and fonts decides whether the page's own look comes with it, and Apply Readability.js narrows a page to its article but leaves a selection alone. Adding with nothing selected stops and says the selection is empty.
The chapters wait in the extension, not in a file. They survive closing the tab and closing the browser, and they stay there until you generate the book, remove them, or run Save Page or Save Selection, which start a new book and discard what was collected.
Edit Chapters ... opens all of it in a tab of its own. It is the same editor Review Before Saving opens, holding a whole book rather than one page.
| eBook Title | What the book is called, and what the file is named after. Left empty, the book is called eBook. |
| eBook Stylesheet | Folded away until you open it. CSS for the whole book, every chapter of it. Not the same as the Style Library, which cleans up pages on the way in. |
| eBook Details | Also folded away. Authors, language, publisher, date and description for the book. A field left empty shows in grey what would be taken from the chapters instead, which is what will be used. |
| The chapter rows | One per chapter, in the order they will be bound. Drag the handle on the left to reorder them, and type in the box to rename one, which renames it in the table of contents. |
| Preview | Opens that chapter on its own, to read it, edit it, style it and describe it. See The Preview dialog. |
| Remove | Takes one chapter out, after asking. It goes when the changes are saved. |
| Cancel | Closes the tab and keeps everything as it was when it opened. |
| Remove Chapters | Throws away the whole collection, after asking: the chapters, the title, the stylesheet and the details. |
| Save changes | Writes the order, the names, the title, the stylesheet and the details, says so, and closes the tab. The chapters stay where they are, ready to be added to. |
| Generate eBook ... | Saves all of that and then builds the .epub and downloads it. An empty book is refused. |
Generating does not empty the collection. The chapters are still there afterwards, so a book can be generated, read, then corrected and generated again. Use Remove Chapters when you want to start the next one from nothing.
Every chapter row in the editor has a Preview button, which opens the chapter over the list. The page it shows is built by the same code that writes the book, so what you are looking at is the chapter as it will be packaged. Pagination, fonts and margins are not in it: those belong to the reading system and differ between devices.
The dialog is also where a chapter is edited, and the rendering is the editing surface, so what you remove is the thing you saw. The toolbar shows only the buttons the current mode can use, and the line under it says what the mode does and, while removing, names the element a click is about to take.
| X | Closes the dialog. Content edits, chapter CSS and chapter details all live in the dialog until they are saved, so if any of them are unsaved you are asked before they go. Escape and a click on the background outside the dialog do the same thing. |
| View | Reading mode, where nothing can be changed by accident. Clicks on links inside the chapter go nowhere. |
| Remove elements | The element under the pointer is outlined, and clicking it takes it out of the chapter. Pictures that nothing points at any more are dropped from the book as well, so removing an image also removes its weight. |
| Select parent | Widens what a click would take, one level up at a time, from a paragraph to the figure or the block around it. Arrow Up does the same. It stops at the outermost element that is yours to remove. |
| Select child | Narrows it back down one level. Arrow Down does the same. Off until you have widened something. |
| Edit text | Makes the chapter editable, so you can click into it and type. Pasting and dropping insert plain text only, because markup from somewhere else would pull in that site's images and would not survive saving anyway. The chapter's title is not edited here, it is edited in the chapter list. |
| Add paragraph before | Puts an empty paragraph in front of the block the cursor is in, or at the very start of the chapter if the cursor is nowhere. It arrives holding the words "New paragraph", selected, so typing replaces them. |
| Add paragraph after | The same, on the other side of that block, or at the end of the chapter. |
| Chapter CSS | Opens a box of CSS for this one chapter, applied after the styles captured from its page. The preview redraws as you type. This is the exception for a single chapter; the stylesheet for the whole book is in the editor behind the dialog. |
| Chapter details | Opens what this chapter says about itself: title, authors, language, publisher, date and description. A field left empty shows what the page said in grey, which is what will be used. Language is the one field a reading system acts on chapter by chapter. |
| Undo | Steps back one change, up to thirty of them. A run of typing counts as one step rather than one character. Ctrl+Z, or Cmd+Z, does the same. |
| Save chapter | Writes the edited content, the chapter CSS and the chapter details onto the chapter. It stays greyed out until there is something to write. Nothing else in the dialog saves anything, so closing without pressing it throws the work away. |
Saving a chapter puts it back in the list. The book itself is still not written until Generate in the editor.
The Style Library holds CSS that is applied while a page is captured. Use it to remove cookie notices, menus, ads, sidebars, comments, and other content that should not enter the EPUB.
This differs from the eBook Stylesheet in the chapter editor:
The extension includes nineteen capture styles. Some apply to particular sites. Others can apply to every page. You can enable them, edit them, duplicate them, or create your own.
To make a style for the current page:
Clear Capture this page first to open the library with its last captured page. This is faster when you do not need a new preview.
A style can apply to every captured page or to addresses matched by domain, URL prefix, glob, or regular expression. The library also supports JSON import and export.
Remote url() and @import references are removed from imported CSS. This
prevents an imported style from contacting another site during capture.
Three panels, left to right: the library, the style being edited, and the page they are tried on.
The library, on the left
| Search name, pattern or CSS | Narrows the list by what you type, looking inside the CSS as well as at the names, so a style can be found by the selector it hides. |
| All, Applies here, Site styles, Every page, On | Filters for, in order: everything; only what covers the page in the preview; only styles tied to a pattern; only styles applied to every capture; only what is switched on. |
| Mine, Built-in | Splits the list by where a style came from: written or imported by you, or shipped with the extension. |
| The checkbox on each row | Switches that style on or off. Off means it exists but is not applied to anything. |
| The row itself | Click to open the style in the middle panel. Underneath the name it says where the style applies, and a badge on the right says Built-in, Edited built-in, Imported or Yours. |
| New site style | Starts a style tied to a pattern, for one site or one part of one. |
| New every-page style | Starts a style applied to every page captured, whatever the address. |
| Import ... | Opens a style file, or takes one pasted in. It says what would be added and what already exists under the same name before writing anything, so a clash can be kept as a separate copy or written over. |
| Export all | Writes the whole library to a JSON file. |
The style, in the middle
| The badge, Duplicate, Export | The badge says where this style came from. Duplicate makes a copy to change freely, which is the way to keep a built-in as it is while trying something else. Export writes this one style to a file. A built-in you have edited also gets Reset to built-in, which puts the shipped version back. |
| Name | What the style is called in the list. |
| Note | A line to yourself about what the style is for. |
| Applies to | Either every page that is captured, or pages matching a pattern. Choosing the pattern reveals how to match (by domain, by address prefix, by a * glob, or by a regular expression), a box for the pattern, and a box holding an address to test it against, which says as you type whether that address matches. |
| CSS | The rules themselves, applied to the page while it is captured, not to the eBook. |
| Hide images, Hide sidebars, Unstick headers, Hide comments, Single column, Bigger text | Ready-made rules, written into the CSS box at a click, to be kept or changed. |
| Remove Style, Save Style | At the foot of the window. Remove asks first. Nothing is applied to a capture until it is saved. |
The preview, on the right
The preview shows a copy of a real page, rendered the way the eBook will show it, with the styles above applied as you type them. Above it, the address it was taken from, and the styles it is showing, listed in the order they were applied.
| Pick element | Point at something in the preview and click it to write the rule that hides it into the style you have open. The line underneath says what the click would hide, and how many elements on the page that rule covers, before you click. |
| Select parent, Select child | Move the pick outwards to the box around what you are pointing at, or back inwards, when the thing you want is not what sits under the cursor. |
| Discard | Throws away the captured page, leaving the library with nothing to preview against. |
The page comes from the popup's Capture this page first checkbox, which is ticked by default unless the page has already been captured. Capturing takes as long as saving the page does, so leave the box clear to open the library straight away on the last page captured. Fonts, margins and pagination are not part of the preview: those belong to the reading system.
Remote url() and @import references are removed from imported CSS: they
would fetch a file from another site every time you saved a page, which tells
that site what you are reading.
sudo apt-get install calibre
ebook-convert "book.epub" "book.mobi"
NOTE These shortcuts are not fixed and the browser will assign a different shortcut if the default one is taken
| Shortcut | Description |
|---|---|
| Alt + Shift + 1 | Save current page as eBook |
| Alt + Shift + 2 | Save current selection as eBook |
| Alt + Shift + 3 | Add current page as chapter |
| Alt + Shift + 4 | Add current selection as chapter |
in Chrome:
1. Navigate to chrome://extensions/
2. Scroll down
3. Click on Keyboard shortcuts
<picture>, srcset, and common lazy loaded images more reliably, including pages that use placeholder pixels.image-set(), imports, and other disguised remote references.images/ directory in text only books, eliminating the associated EPUBCheck warning.Some pages carry things a book should not: a sidebar, a cookie banner, a header that reappears in the middle of a chapter. The old custom style editor was a bare text box where the CSS had to be written by hand. It is a proper library now.
A new option in the popup. With it on, Save Page opens the chapter in an editor instead of downloading straight away, so things can be fixed before the book is made:
The tests are in tests/, and they run the code in web-extension/ rather than
a copy of it.
Node.js. There is nothing to install, the tests have no npm or yarn dependencies.
Google Chrome or Chromium, for the DOM tests. Those need a real browser,
because the extraction code uses getComputedStyle, layout measurements,
canvas.toDataURL and the HTML5 parser behind <template>. Chrome is found
automatically on macOS, and through google-chrome or chromium on PATH.
Otherwise set CHROME=/path/to/chrome.
EPUBCheck, to validate a generated book. Install it with
brew install epubcheck, or download a
release and set
EPUBCHECK_JAR=/path/to/epubcheck.jar, which also needs java on PATH.
When Chrome or EPUBCheck is missing, the steps that need them print SKIP and
everything else still runs.
cd tests
./run-all.sh
It prints a section per stage. It ends with ALL PASSED and exit code 0, or
with a list of the failures and exit code 1. A full run takes a couple of
minutes. The books it builds are written to tests/out/, which is git ignored,
so you can open them in a reader afterwards.
cd tests
./run-dom-tests.sh # every fixture in tests/dom/, in headless Chrome
node utils.js # pure helper functions
node style-library.js # style matching, and the v1 custom style migration
node background.js # background jobs and message state
node outline.js # chapter outline and navigation tree
node epub-builder.js # EPUB builder scenarios
# build a book with the extension's own saveEbook.js, then check it
node build-epub.js out/fixture.epub # a book of several chapters
node build-epub.js out/single.epub --single # a one chapter book
node check-epub.js out/fixture.epub # structural checks, no JVM needed
./run-epubcheck.sh out/fixture.epub # the official validator
# build a book out of chapters edited in the chapter editor, then validate it
./build-edited-epub.sh
# check that each test in check-epub.js rejects a broken archive
node check-epub-negative.js out/fixture.epub
To run one DOM fixture instead of all of them, open it in a browser, for example
tests/dom/mathml.html, and read the PASS and FAIL lines it renders.
check-epub.js and check-epub-negative.js need a book to inspect, so run the
matching build-epub.js first. run-epubcheck.sh builds one itself when the
file is not there.
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