XSLT is leaving Chrome: what breaks and what to do

What changes on 17 November 2026

XSLT is the language that turns an XML document into a readable page, using an XSL stylesheet that the XML file points to. Chrome is removing it. Chrome’s announcement gives this timeline:

Chrome version	Date	What happens
Chrome 143	2 December 2025	XSLT is officially deprecated. Warnings appear in the developer console and in Lighthouse.
Chrome 158	17 November 2026	XSLT stops working on Stable releases, for all users other than origin trial and enterprise policy participants.
Chrome 176	17 August 2027	The origin trial and the enterprise policy stop working. XSLT is disabled for all users.

Chrome Beta, Dev and Canary began disabling XSLT by default from Chrome 145, as an early warning.

The reason is security. Chrome explains that the libraries that run these transformations, such as libxslt, are complex C and C++ code, and that this kind of code is prone to memory safety vulnerabilities such as buffer overflows.

Pages you may notice

Chrome says that only about 0.02% of web page loads use XSLT at all, and less than 0.001% use XSLT processing instructions, the line in an XML file that points to a stylesheet. Rare, then, but concentrated on a few kinds of pages:

• WordPress sitemaps. Since WordPress 5.5, WordPress exposes a sitemap index at /wp-sitemap.xml and provides XSL stylesheets to style all its sitemaps. See how to view a WordPress sitemap.
• Styled RSS and Atom feeds. Chrome notes that in many existing feeds, XSLT is used to make the raw XML human-readable when you open the feed directly in the browser. See what to do when an RSS feed shows as plain text.
• Embedded devices. Chrome mentions commercial devices that generate XML data for users on the local network, and adds that many such devices are difficult or impossible to update. For those, Chrome points to the browser extension.

What you see instead

When XSLT is off, the stylesheet is no longer applied, so the layout it built disappears: no table, no headings, no clickable links. According to Chrome’s announcement, Chrome shows a warning banner that links to a Chrome Web Store search for “xslt polyfill”, to help you find an extension.

We checked what the page itself looks like. In Chromium 156 with XSLT turned off, an XML page linked to an XSL stylesheet showed the message “This document cannot be formatted as intended”, followed by the raw XML: the tags and the text of the file, without any layout.

Your options

Option	For	Effort
XMLNest	Visitors	One click
Official XSLT Polyfill extension	Visitors	One click
xslt-polyfill script on the site	Site owners	Small code change
Render to HTML on the server	Site owners	Larger change
XSLTEnabled enterprise policy	IT teams	Until 17 August 2027

A visitor cannot change the site, but an extension can apply the stylesheet again in their own browser. A site owner can fix the page for every visitor at once. IT teams that manage Chrome can use the XSLTEnabled policy to buy time, until Chrome 176.

XMLNest or the official XSLT Polyfill extension?

Chrome’s announcement links to one extension, XSLT Polyfill, which applies the xslt-polyfill library to raw XML pages that use XSLT. XMLNest is an independent extension built on the same open-source library. Here is how they differ:

	XSLT Polyfill (official)	XMLNest
Engine	xslt-polyfill	xslt-polyfill
Site access at install	All sites, according to Chrome-Stats	None: turn it on everywhere in one click, or site by site
JavaScript that uses XSLTProcessor	Supported, according to its Store page	Not offered
XML without a stylesheet	Its Store page says it does nothing there	Collapsible tree with search, source view, reader views for feeds and sitemaps
Price	Free, according to Chrome-Stats	Free

Both process pages locally, in your browser. XMLNest also keeps scripts contained in transformed pages from running unless you allow them for that site.

If you only need styled XML pages back and want the extension Chrome links to, the official one is a good choice.

For site owners

Chrome lists several ways to keep XML pages readable without the browser’s own XSLT.

Transform on the server. Run the XSLT transformation on your server and send the resulting HTML.

Add the xslt-polyfill script. The xslt-polyfill README shows a script element placed directly in the XML document, as a child of its root element, after the line that links the stylesheet:

<script src="../xslt-polyfill.min.js" xmlns="http://www.w3.org/1999/xhtml"></script>

Keep the xmlns attribute: the README explains that the script element must be in the XHTML namespace to run. The polyfill implements XSLT 1.0 only; for newer XSLT, the README points to SaxonJS.

For feeds. Chrome suggests adding a <link rel="alternate" type="application/rss+xml"> element to the HTML pages of your site, or adding the polyfill script to the feed itself.

Move to JSON. Chrome also lists serving JSON instead of XML and rendering it on the page with JavaScript.

Need more time? Chrome’s origin trial lets a site keep XSLT past 17 November 2026, until Chrome 176 on 17 August 2027.