Asciidoctor.js Live Preview

Render AsciiDoc (.ad, .adoc, .asc, .asciidoc) as HTML inside your browser!

This project uses Asciidoctor.js to render AsciiDoc as HTML. Usage 1. Check Allow access to file URLs in chrome://extensions 2. Open local or remote .adoc or .asciidoc file in Chrome 3. Enjoy! Options The extension can be configured via an options page. To open the options page, right-click the extension icon and choose Options on the menu. You can also go to chrome://extensions and click the Options link. The options page let you add custom attributes or change the theme of the AsciiDoc HTML output. Changelog 4.1.0 (2026-08)07 • Remove the redundant broad `file://*/*` entry from the manifest's `host_permissions`: reading a local file with a non-AsciiDoc extension (e.g. an `include::` or `chart::` target like a `.csv` chart data file) already works through the `file://*/*` access already granted via `web_accessible_resources`, so declaring it a second time in `host_permissions` had no effect other than showing up in the install-time permission list • Fix a redundant border appearing under the document title on wide screens (`toc2` layout) when the document has an author or revision info • Fix a `file://` document failing to reload (`TypeError: Failed to fetch`, or on Chrome "'file:' URLs are treated as unique security origins") after clicking an in-page anchor link (e.g. a ToC entry): the tab's URL keeps the `#fragment` from the anchor, which fetch() doesn't strip for `file://` the way it does for http(s); the fragment is now stripped before fetching, and before computing the `docfile`/`docname` attributes and the auto-reload cache key • Remove the `fontawesome-webfont.ttf` and `fontawesome-webfont.woff` entries from the manifest's `web_accessible_resources`: only the `.woff2` file is actually bundled, and the Edge Add-ons validator rejects the package when a listed resource doesn't exist in the archive • Remove the `downloads` permission: "Export as HTML" now triggers the download through a hidden `<a download>` link injected into the page instead of `chrome.downloads.download()`, which also makes the feature available on Safari and Firefox for Android, where the `downloads` API doesn't exist (#722) • Fix a Chrome console error ("Denying load of .../fontawesome-webfont.woff... Resources must be listed in the web_accessible_resources manifest key") on every page: the vendored Font Awesome stylesheet still declared `@font-face` fallbacks (`.eot`, `.woff`, `.ttf`, `.svg`) for font files that were dropped from the extension a decade ago, so the browser kept trying to load them; the build now rewrites the stylesheet to only reference the bundled `.woff2` file 4.0.0 (2026-08-06) • Migrate to Asciidoctor.js 4.0 (replace `XMLHttpRequest` by `fetch`) • Remove Bulma and Sass, replace the generated options page stylesheet with a small hand-written CSS file • Fix custom JavaScript being blocked on pages with a strict Content-Security-Policy: run it in the page's main world via `chrome.scripting.executeScript`, loaded from a `Blob` URL script `src`, instead of appending an inline `<script>` from the content script • Prevent a flash of unstyled/light content while the document is being fetched and converted: hide the page at `document_start` (matching the reader's OS-level dark/light preference) and reveal it once rendering finishes • Add a "Remove" button next to the JavaScript dropdown in the options page, to delete a previously added custom script, and fix the existing theme "Remove" button to also clear the entry from `browser.storage.local` (it was only clearing `localStorage`, leaking the stylesheet content indefinitely) • Make the default `asciidoctor` theme dark-mode compatible, matching the reader's OS-level `prefers-color-scheme`: dark syntax highlighting (`atom-one-dark`, when the `github` highlight theme is in use), fix table row striping and admonition icon colors that a specificity conflict in the base theme had left unstyled or too dark, and restyle inline Kroki `<svg>` diagrams (`filter: invert(1) hue-rotate(180deg)`) for documents that opt in with `:kroki-default-options: inline` (requires an `asciidoctor-kroki` version with the browser `toDataUri` fix) • Fix removing a custom theme not reliably restoring the default `asciidoctor` theme (even after a refresh): the reset relied on a debounced autosave that could be skipped or lost, so save it immediately instead • Render the author(s) and revision info (number, date, remark) in a `#header` block above the table of contents, matching Asciidoctor's standalone output, since the embeddable output the extension uses never included them, with a small margin below it so the preamble isn't flush against the title/details (#460) • Add support for the `:favicon:` document attribute (#688) • Fix the "Render selection" context menu action, which was broken in several ways: `inject.html` referenced JavaScript files that no longer exist (`namespace.js`, `converter.js`, `renderer.js`, leftovers from before the switch to ES modules) and loaded `inject.js` as a classic script even though it uses `import`; the context menu handler used `tabs.executeScript` and `extension.getViews`, both removed in Manifest V3; and applying the theme CSS failed too because `chrome.scripting` can't target the extension's own pages -- CSS is now applied directly to the document in that case, and a configured custom JavaScript is skipped there since there's no CSP-compliant way to run it on an extension page (#113) • Fix auto-reload rebuilding the whole page on every poll tick even when the fetched content hadn't changed, which reset the page and dropped any in-progress text selection (most noticeable in the plain-text rendering, where selecting/copying the source is the whole point); skip the DOM update when the content is unchanged • Fix a custom theme being silently shadowed by a built-in theme of the same name (e.g. a user-uploaded `asciidoctor.css`): a custom theme now takes precedence over a built-in one when both share a name (#304) • Stop polling for changes while the tab is hidden, so a backgrounded tab doesn't keep fetching and converting the document on every tick (#232) • Add a keyboard shortcut (`Alt+Shift+R` by default, configurable at `browser://extensions/shortcuts`) to toggle between the rendered and raw view (#186) • *Behavior change*: only `.adoc` and `.asciidoc` files are rendered by default now; `.ad` and `.asc` join `.txt` as opt-in extensions, each with their own checkbox on the options page (#677) • Fix the bottom padding being too tight when a document has footnotes: the base stylesheet zeroes it out to avoid double-spacing before `#footer`, but the extension's embeddable output never renders a `#footer` (#120) • Open the quickstart guide in a new tab the first time the extension is installed (#528) • Fix the quickstart guide reopening every time the extension is turned off and back on in Safari's Extensions preferences: Safari fires `runtime.onInstalled` with reason `install` on every re-enable there, not just on a true first install, so guard it with a persisted flag instead of trusting the reason alone • Fix the on/off toolbar toggle getting stuck once the background script has been restarted since the last click (e.g. after the browser reclaims an idle MV3 background context, which Safari does aggressively): the toggle tracked its enabled/disabled status in a module-level variable that silently reset on every restart instead of reading it back from `storage.local`, so a click could flip the wrong way without any error • Document that local `file://` documents aren't supported in Safari, a platform limitation with no current workaround (`docs/modules/ROOT/pages/safari-known-issues.adoc`) • Fix Asciidoctor `WARNING` messages (e.g. an unterminated block) showing up as errors in the browser console: they're now logged with `console.warn`, reserving `console.error` for actual `ERROR`/`FATAL` messages • Add an "Export as HTML" feature (right-click menu on a rendered page, or the `Alt+Shift+E` keyboard shortcut) that saves the document as a standalone HTML file, matching what `asciidoctor file.adoc -o file.html` would produce; not available where the `downloads` API is missing (Safari, Firefox for Android) (#148) 3.0.0 • Migrate to manifest v3 -- `include` won't work anymore! • Migrate documentation to Antora: https://docs.asciidoctor.org/browser-extension/ • Reorganize use-cases to separate page, try-it-yourself to a quickstart page, diagrams try-it-yourself to a diagrams quickstart page (#652) (#654) 2.7.1 • Add `accept` header when fetching AsciiDoc content (mainly to workaround an issue on github.com) • Update dependencies 2.7.0 • Fix MathJax equation numbering (#412) • Upgrade Asciidoctor.js from 2.2.0 to 2.2.1(based on Asciidoctor 2.0.12) • Upgrade Asciidoctor Kroki from 0.8.2 to 0.12.0 (add excalidraw, bpmn and bytefield as a supported diagrams) • Global configuration using `kroki-default-format` and `kroki-default-options` attributes • Upgrade bulma from 0.8.2 to 0.9.1 2.6.1 • Do not add the toc2 class if the document has no section - thanks @mnrvwl • Stop auto reload when the extension has been disabled - thanks @mnrvwl • Remove the deprecated options_page - thanks @mnrvwl • Upgrade Asciidoctor.js from 2.1.1 to 2.2.0 • Upgrade Asciidoctor Kroki from 0.7.0 to 0.8.1 • Support sidebar toc • Compatibility with Firefox, use the same codebase again! • Remove chartist sourcemap reference 2.5.0 • Upgrade Asciidoctor.js from 2.0.3 to 2.1.1 • Show errors thrown by the background script on the page (thanks @doub) • Catch exceptions thrown by the initial XMLHttpRequest • Use the `Cache-Control` header to make sure that we fetch the latest version available • Upgrade Asciidoctor Kroki from 0.4.0 to 0.7.0 with new diagrams: `packetdiag`, `rackdiag`, `vega` and `vegalite` • Upgrade chartist from 0.11.0 to 0.11.4 • Upgrade bulma from 0.7.5 to 0.8.2 2.4.0 • Move the fetch and convert functions in the background script (as the latest version of Chrome 80+ blocks `XMLHttpRequest` sent by the content script) • Upgrade to MathJax 3.0.1 2.3.0 • Upgrade to MathJax 3.0.0 (thanks @sindzicat) • Use server-side syntax highlighting (thanks @john-cj) 2.2.0 • Fix inter-document cross references by using `.adoc` as `outfilesuffix` (thanks @jmini) • Disable the diagram extension by default (can be enabled in options page) • The Kroki server URL can now be configured in the options page (for instance, you can point to a local instance) 2.1.0 • Set built-in attributes docfile, docname and docfilesuffix (thanks @utopalex & @ehmkah) • Use Kroki extension to render diagrams (support BlockDiag, SeqDiag, ActDiag, NwDiag, C4, Ditaa, Erd, GraphViz, Mermaid, Nomnoml, PlantUML, SvgBob and UMLet diagrams!) 2.0.0 • Load additional languages for highlight.js (using :highlightjs-languages: attribute) • Upgrade to Asciidoctor.js 2.0.3 • The default safe mode is now safe (was secure)