How to Install SingleFileZ in Firefox on Ubuntu and Save Webpages
SingleFileZ has merged into SingleFile. Install its successor in Firefox on Ubuntu, save a webpage as one file, and choose self-extracting output.
Short answer: SingleFileZ has been merged into SingleFile. On Ubuntu, install the current SingleFile extension from Firefox Add-ons, open the page you want to keep, wait for it to load, and click the SingleFile toolbar button. The saved file goes to Firefox’s configured download folder. If you specifically want SingleFileZ’s self-extracting style of file, choose the appropriate option under SingleFile’s File format settings.
The old SingleFileZ listing may still appear on Firefox Add-ons, but its listed version 1.4.45 was last updated February 15, 2024. Treat it as a legacy listing: the project points users to SingleFile following the merger. See the SingleFileZ listing and the current SingleFile project.
1. Install the current extension in Firefox on Ubuntu
- Open Firefox on Ubuntu.
- Go to the SingleFile page on Mozilla Add-ons.
- Choose the control to add the extension to Firefox and accept Firefox’s confirmation prompt.
- When installation finishes, look for the SingleFile button in the toolbar. If it is not visible, open Firefox’s extensions menu and pin the button to the toolbar.
This is a Firefox extension installation, not an Ubuntu package installation. The project documents the Firefox Add-ons route; it does not provide a separate Ubuntu package or Ubuntu-specific terminal command for installing SingleFile. Mozilla also documents installing add-ons from its add-ons site and, in some cases, from a saved XPI through Add-ons Manager. Use the official listing for the normal installation path.
2. Save a webpage as one file
- Navigate to the page you want to preserve.
- Wait until the page has finished loading. If it relies on images or other content that appears later, wait for that content too.
- Click the SingleFile toolbar button. The extension processes the page and starts a download.
- Open the file from Firefox’s downloads panel, or find it in Firefox’s configured download folder.
SingleFile saves a complete page and its resources, such as images and styling, into one HTML file. The exact result depends on what the page exposes to the browser when it is captured. A page that requires a live server, account session, streaming media, or dynamic application code may not behave exactly the same when opened offline.
Save a selection, frame, or multiple tabs
For alternatives to saving the entire current tab, use the extension’s context menu. The project documents options to save selected content, a selected frame, or multiple tabs. The exact menu labels can vary with the extension version and browser language.
3. Choose the self-extracting format associated with SingleFileZ
SingleFileZ’s project directs users to SingleFile’s options to choose a self-extracting file format. Open SingleFile’s options, find File format, and select the format that matches your needs before saving. Existing SingleFileZ settings can be imported according to the project’s merger notice.
Older SingleFileZ documentation describes a .zip.html filename convention. That is legacy behavior; follow the current SingleFile format choices rather than assuming every old filename or setting is unchanged. A saved file can preserve page content, but it cannot guarantee that every interactive feature or externally hosted resource will work offline.
4. Manual installation and extension updates
If you have a reason to install manually, the SingleFile project documents a project ZIP download and Mozilla’s temporary add-on installation process. This is primarily useful for development or troubleshooting, not the recommended everyday setup:
- Download the project ZIP from the SingleFile repository and extract it.
- In Firefox, open
about:debugging, then choose This Firefox. - Choose Load Temporary Add-on and select the extension manifest from the extracted Firefox extension directory, following the project README’s instructions.
A temporary add-on installation is for the current Firefox session and may need to be repeated after the browser restarts. For a regular installation, use the Mozilla Add-ons listing so Firefox manages installation and updates.
5. Troubleshooting
| Problem | Likely cause | What to do |
|---|---|---|
| Searching for SingleFileZ finds an older extension | The old listing remains visible although its project has merged into SingleFile. | Install SingleFile for the current project and configure the file format there. |
| The add-on cannot be installed | Firefox may be managed by an administrator, the browser may be unable to reach Mozilla Add-ons, or installation may be blocked by browser policy. | Check the Firefox error message, network access, and any managed-browser restrictions. Mozilla’s add-on installation troubleshooting covers common blocks. |
| The toolbar button is missing | The button may be in the extensions menu or not pinned. | Open Firefox’s extensions menu and pin SingleFile to the toolbar. |
| The page is missing images or content | Some content may not have loaded before capture or may be loaded only after scrolling or interaction. | Wait for the page and its important content to appear, then capture again. For content revealed only by interaction, trigger it before saving. |
| The saved page does not work fully offline | Some sites depend on server responses, external resources, login sessions, or scripts that need a live service. | Use the saved file as a preserved page snapshot; keep the original URL for functionality that depends on the site. |
| A temporary manual installation disappears | Firefox temporary add-ons are intended for temporary loading. | Use the Mozilla Add-ons listing for a persistent user installation. |
| The output is HTML rather than the format expected | SingleFile’s selected file format controls output; historical SingleFileZ settings may not carry over automatically. | Review SingleFile options under File format and choose the self-extracting option before saving. |
6. Reliability, privacy, and file-size considerations
- Capture after loading: A capture reflects what Firefox can access at capture time. Waiting for lazy-loaded images and page content improves completeness.
- Offline behavior varies: Static text and embedded resources are better candidates for offline viewing than pages built around live APIs, login checks, or media streams.
- File size: Embedding page resources into one file can make the output larger than the HTML source alone. Pages with many large images or fonts require more disk space.
- Local restrictions: Browsers can apply different restrictions to pages opened from the filesystem. Do not assume that every saved page can access local or remote resources identically across browsers.
- Ubuntu specifics: The documented workflow is the Firefox extension workflow and does not depend on an Ubuntu-only command. Ubuntu Firefox packaging variants are outside the extension’s documented installation path.
7. Or skip the browser setup
If your goal is to capture a URL from code rather than keep a local browser archive, ScreenshotNeo provides a website screenshot API and MCP server. A single request returns an image or PDF. This is a rendered screenshot, not a self-contained HTML archive like SingleFile.
See the ScreenshotNeo API documentation. cURL:
curl -G "https://api.screenshotneo.com/v1/shot" -d access_key=YOUR_API_KEY --data-urlencode url=https://stripe.com -o shot.webpPython:
import 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)Node.js:
const q = new URLSearchParams({ access_key: 'YOUR_API_KEY', url: 'https://stripe.com' });
const res = await fetch(`https://api.screenshotneo.com/v1/shot?${q}`);
if (!res.ok) throw new Error(`Screenshot request failed: ${res.status}`);
const bytes = new Uint8Array(await res.arrayBuffer());
await import('node:fs/promises').then(fs => fs.writeFile('shot.webp', bytes));ScreenshotNeo removes cookie banners, newsletter popups, and chat widgets before capture. 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; paid plans start at $5 for 3,000 screenshots. Create a free ScreenshotNeo account to get started.
Frequently asked questions
Is SingleFileZ still a separate current project?
The SingleFileZ repository says it has been completely merged into SingleFile and directs users to the successor project.
Can I use the saved page as a backup of a web application?
It preserves the page as captured, but a snapshot is not a substitute for the application’s data, backend, or account services.
Does this require a terminal command on Ubuntu?
No. The documented regular installation route is through Firefox Add-ons. The instructions do not specify an Ubuntu package or terminal command for the extension.
