How to Open a SingleFile HTML Archive Offline

To open a SingleFile archive offline, open its saved .html file in a browser. Find the file in the folder where it was saved—usually your browser’s configured download folder—and double-click it, or choose the browser’s Open File command and select it. You do not need the SingleFile extension just to view the saved page.

SingleFile saves a web page and captured resources such as images, stylesheets, fonts, and frames into one HTML file. It is an ordinary HTML document that browsers can display offline. The result is a snapshot, though: it does not guarantee that every interactive feature or remote service from the original site will work without a network connection. See the SingleFile project overview and its README.

1. Open the saved HTML file

1. Locate the SingleFile output. Check the folder configured for downloads in your browser, or the alternate folder you chose when saving.
2. Confirm the file name ends in .html. It should be the saved page itself, not a bookmark or shortcut to the original website.
3. Open the file in a current browser. Double-click it in your file manager, or use the browser’s Open File command and select the file.
4. If your computer asks which app to use, choose a web browser.

The extension is for capturing pages and providing extension features; it is not required to display an existing archive. If the file opens as source code in a text editor, close it and open it from a browser instead.

2. What works offline, and what may not

Captured and embedded page resources can be rendered from the local HTML file without contacting the original site. However, the archive is a saved representation of a page, not a guarantee of a complete offline copy of the site’s behavior.

Page content	What to expect offline
HTML and resources embedded in the archive	Usually display from the local file.
Links to other pages	May navigate to a remote URL and need a connection.
Features backed by a remote service	May not load or respond without that service.
JavaScript-driven controls	May be absent or behave differently. SingleFile removes scripts by default because they can alter rendering and may not work offline.
Resources that were not captured	May be missing. For example, the SingleFile FAQ notes that some sites require a Referer header to retrieve images.

The SingleFile FAQ specifically mentions folding titles, dynamic maps, and carousels as features that may not behave properly offline. Keeping scripts for a future capture may help with some pages, but it cannot make remote services available without a connection. Changing extension settings after a file has been saved also cannot add content that is already missing from that file. Read the official SingleFile FAQ for its notes on scripts and resource capture.

3. SingleFile infobar and file access permission

If the saved page opens but SingleFile’s infobar does not appear, the archive can still be opening correctly. The extension’s Allow access to file URLs permission is relevant when you want the extension’s infobar on local files; it is not a requirement for the browser to display the HTML.

1. Open your browser’s extensions management page.
2. Find SingleFile and open its details or permissions.
3. Enable Allow access to file URLs if you specifically need SingleFile’s local-file infobar.
4. Reopen or refresh the local archive if needed.

Browser labels and settings locations can vary. If the archive itself displays normally, you can skip this permission.

4. Troubleshooting

Symptom	Likely cause	What to do
The file cannot be found	It was saved to the browser’s configured download folder or another chosen location.	Check the browser’s download history and configured download location, then open that file.
The browser shows markup as text	The file was opened in a text editor or another app instead of a browser.	Use the browser’s Open File command or choose a browser from the file manager’s Open With menu.
The SingleFile infobar is missing	The extension may not have permission to access local file URLs.	Enable Allow access to file URLs if you need the infobar. Its absence alone does not mean the archive failed.
Images or layout are incomplete	A resource may not have been captured or embedded; some sites restrict resource retrieval, including through Referer-dependent behavior.	Reconnect and check whether remote resources become available. If they do, the file is not fully self-contained. For a durable offline copy, recapture the page with the needed content available and review the capture settings.
A map, carousel, or control does not respond	It may depend on JavaScript that was removed, or on a service that needs the network.	Reconnect to distinguish a network dependency from a script limitation. For a new capture, review SingleFile’s options for retaining scripts; this does not repair an existing archive.
The file opens a live website instead of a local page	You may have opened a shortcut or link rather than the saved HTML file.	Check the extension and file details, then open the actual saved .html document.

5. When an HTML snapshot is not enough

For professional or academic web archiving, SingleFile’s own FAQ cautions that it is not a complete preservation solution and points readers toward tools based on the WARC specification. Choose an archiving workflow based on your preservation requirements; this guide does not compare particular WARC tools.

Or skip the browser setup

If your goal is to capture a live web page as an image or PDF instead of opening an existing SingleFile archive, ScreenshotNeo provides a screenshot API and MCP server for developers. See the API documentation.

curl -G "https://api.screenshotneo.com/v1/shot" -d access_key=YOUR_API_KEY --data-urlencode url=https://stripe.com -o shot.webp

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)

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}`);
await Bun.write('shot.webp', new Uint8Array(await res.arrayBuffer()));

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; paid plans start at $5 for 3,000. Sign up for free and get 1,000 screenshots a month with no card.

FAQ

Can I open a SingleFile archive on a computer without the extension?

Yes. Open the saved HTML file in a browser; the extension is not needed to display it.

Does no infobar mean the file did not open?

No. The infobar is an extension feature. File URL access is only needed if you want that feature on a local file.

Will every interactive feature work offline?

No. Scripts may be removed, and remote services or uncaptured resources may remain unavailable.

Is a SingleFile HTML file a professional archive?

For professional or academic preservation, the project FAQ recommends considering WARC-based tools.