How to Use SingleFileZ in Firefox to Archive a Webpage
Save a webpage from Firefox as one self-extracting HTML/ZIP file, then learn how to open it, capture tabs or selections, and fix incomplete saves.
To archive the page open in Firefox, wait for it to finish loading, then click the SingleFileZ button in the extension toolbar. When processing finishes, Firefox saves one self-extracting HTML file that is also a ZIP archive containing page resources. The current SingleFileZ repository says the project has been merged into SingleFile; if you are following the maintained path or cannot install SingleFileZ, use SingleFile’s “File format” options to save a self-extracting file.
The Firefox Add-ons listing for SingleFileZ still lists version 1.4.45, released February 15, 2024. That listing and the maintainer’s migration notice coexist. Check current Firefox Add-ons availability, and do not assume the listed version is current software.
1. Install and save the current webpage
- In Firefox, check whether SingleFileZ is available to install. If it is unavailable, or you prefer the maintained path, install SingleFile and use its “File format” option for self-extracting files. The SingleFileZ repository states that SingleFileZ has been completely merged into SingleFile.
- Open the page you want to preserve and wait until it has fully loaded. Pages that are still loading may not have all their content or resources ready to capture.
- Click the SingleFileZ toolbar button. Wait for processing and for Firefox to finish saving the file. If processing is underway and you need to stop it, click the button again to cancel.
- Find the saved file in Firefox’s configured download location. The output is a single HTML file that is also a valid ZIP containing page resources; the default filename extension is
.zip.html. - Open the saved file in Firefox. JavaScript must be enabled for these saved pages to open correctly. Keep the original archive if you plan to move or share it.
2. Save a selection, frame, link, or multiple tabs
Right-click the SingleFileZ toolbar button or the webpage to open its context menu. The available actions include saving the current tab, selected content, a selected frame, or a selected link. The menu can also process selected tabs, unpinned tabs, or all tabs in one action.
For a keyboard shortcut, use the customizable Ctrl+Shift+Y shortcut to save the current tab or selected tabs. If the shortcut conflicts with another extension or browser command, change it in Firefox’s extension shortcut settings.
The context menu also offers auto-save after pages load for the current tab, unpinned tabs, or all tabs. Auto-save is useful for repeated capture workflows, but it can produce many files; check the download destination and naming settings before enabling it across all tabs.
3. Configure destinations and save behavior
Right-click the toolbar button and choose “Manage extension” to open SingleFileZ’s options. The add-on listing describes optional Google Drive and GitHub destinations under “Destination.” They are optional settings; the basic workflow saves locally through Firefox’s configured download location.
SingleFileZ performs page processing in the browser and its maintainer says it does not upload data to third-party servers. It may still fetch page resources such as images, CSS, frame contents, and fonts that are present in the page but not displayed or cached. If you choose an optional Google Drive or GitHub destination, that changes where the resulting archive is saved.
4. Understand the archive and where it opens
The saved artifact is a self-extracting HTML/ZIP hybrid: it presents as an HTML page and is also a valid ZIP containing the page’s resources. This format keeps the page and its assets together in one file, which is convenient for local storage and offline reading.
Opening behavior depends on the browser. The maintainer’s FAQ says Firefox can view these files from the filesystem. Safari’s instructions require choosing “Disable Local File Restrictions” in the Develop menu. Chrome requires the SingleFileZ extension to open these files from the filesystem. The FAQ says those local-file restrictions do not apply when the saved page is hosted on a server. These are format- and browser-specific qualifications, not a guarantee that every interactive part of the original site will work offline.
5. Make slow saves faster without losing needed content
SingleFileZ’s default configuration is optimized to make small pages, and that can make processing slower and use more CPU. In the extension options, the maintainer suggests disabling these optimizations to reduce save time and CPU use:
- HTML content > remove hidden elements
- Stylesheets > remove unused styles
If processing remains slow, the FAQ also suggests disabling HTML content > remove frames or Images > save deferred images. These changes can make an archive less complete: frames or images may be missing. Change one setting at a time, then inspect the saved page before relying on it as a complete record.
6. Troubleshoot common problems
| Symptom | Likely cause | What to do |
|---|---|---|
| The toolbar action does nothing on a page | Browsers block extensions from running on some browser-controlled or restricted pages for security reasons. | Try an ordinary webpage. A blocked browser page is an extension-access restriction, not necessarily a configuration problem. |
| The saved page is missing content or resources | The page may not have finished loading, or the resource may be deferred, inside a frame, or otherwise unavailable during capture. Speed-oriented settings can also omit frames or deferred images. | Wait for the page to finish loading and save again. Review the frame and deferred-image options, then inspect the archive. |
| Saving takes a long time or uses substantial CPU | Removing hidden elements and unused styles can take extra processing. | Disable “HTML content > remove hidden elements” and “Stylesheets > remove unused styles.” If needed, test the frame and deferred-image options, accepting the possibility of missing resources. |
| The file downloads but will not open locally | Local-file support differs by browser, and JavaScript is required. | Use Firefox with JavaScript enabled. For Safari, consult the FAQ’s local-file instruction. Chrome requires the extension for local files in this format. Hosting the saved file on a server avoids the local-file restriction described in the FAQ. |
| The keyboard shortcut does not save the intended tab | The shortcut may have been customized or may conflict with another command. | Use the toolbar button or context menu, or inspect and customize the extension shortcut in Firefox. |
| The archive is unexpectedly large | The page may contain many resources, including resources not visible or cached when you viewed it. | Review the capture options and expected completeness. Disabling resource-saving options can reduce what is included, so verify the archive meets your needs. |
7. Choose the right capture for the job
- Offline reading or a local record: use SingleFileZ or SingleFile’s self-extracting format, then open the resulting file in a compatible browser.
- A particular passage or embedded frame: use the context menu’s selected-content or selected-frame action.
- A repeatable set of pages: use selected-tabs, unpinned-tabs, or all-tabs actions, and consider auto-save only after choosing a suitable destination.
- A visual record rather than an interactive page archive: a screenshot can preserve the rendered appearance, but it is an image or PDF, not a self-contained HTML archive.
Or skip the browser setup
For a rendered screenshot or PDF rather than an offline HTML archive, ScreenshotNeo is a website screenshot API and MCP server. One GET request captures a URL; its API options include full-page capture, PDF, custom viewport, and waiting for a selector, delay, or network idle. See the ScreenshotNeo API documentation.
curl -G "https://api.screenshotneo.com/v1/shot" -d access_key=YOUR_API_KEY --data-urlencode url=https://stripe.com -o shot.webpimport requests
r = requests.get("https://api.screenshotneo.com/v1/shot", params={"access_key": "YOUR_API_KEY", "url": "https://stripe.com"}, timeout=90)
open("shot.webp", "wb").write(r.content)const q = new URLSearchParams({ access_key: 'YOUR_API_KEY', url: 'https://stripe.com' });
const res = await fetch(`https://api.screenshotneo.com/v1/shot?${q}`);ScreenshotNeo removes cookie banners, popups, and chat widgets before the shot; bot checks, blank pages, and failed loads are never billed. Its MCP server lets AI agents take screenshots. The free plan includes 1,000 screenshots a month with no card, and paid plans start at $5 for 3,000. Create a free ScreenshotNeo account.
FAQ
Can I save a webpage in Firefox as one file?
Yes. SingleFileZ saves a self-extracting HTML/ZIP file. The maintained SingleFile extension also supports self-extracting files through its “File format” options.
Can I use SingleFileZ on every Firefox page?
No. Browser security rules prevent extensions from running on some pages, including certain browser-controlled pages.
Does the archive preserve the live website?
It preserves a captured page and its resources as a local file. It is not a live copy of the site: remote services, dynamic behavior, or resources unavailable at capture time may not work offline.
Does saving a page send it to a server?
The maintainer says SingleFileZ processes locally and does not upload data to third-party servers. Optional cloud destinations such as Google Drive or GitHub are separate destination settings.
