Chrome is removing XSLT: what happens and when

Last verified against Chrome's published timeline: October 23, 2026

Timeline

These dates and version numbers come from the official Chrome page on deprecating XSLT and the Chrome Platform Status entry, as read in October 2026. Some early reports said Chrome 155; Chrome's current documentation and Platform Status entry say Chrome 158, with the same November 17, 2026 date. Some earlier posts gave different version numbers for the same dates, so follow the dates.

Other engines are moving the same way. Mozilla posted an “Intent to Unship: XSLT” in August 2026 (Mozilla's “Intent to Unship: XSLT” post, tracking bug), planning to disable it first in Nightly and in all channels in August 2027. WebKit has indicated support for removal; Chrome's page links to its position, and no Safari date is published.

What is removed

Two things go. The XSLTProcessor JavaScript class, and the XSLT processing instruction in XML files: <?xml-stylesheet type="text/xsl" href="..."?>. The same xml-stylesheet instruction keeps working with type="text/css".

Who is affected

• Sites with styled sitemaps. Several WordPress SEO plugins, static site generators and sitemap tools add an XSL file so the sitemap looks like a table.
• Sites with styled feeds. RSS and Atom feeds that link an XSL file for people who click the feed address.
• Web apps that call XSLTProcessor to turn XML from an API into HTML in the browser.
• Devices and internal tools that serve XML plus XSL from firmware or an old back end and cannot be updated easily.

Not affected: search engine crawlers and feed readers, XML styled with CSS, and any transform that runs on a server or in a build step.

What breaks

Open an XML file with an XSLT stylesheet line in Chrome after the date and you see the XML tree, with element names, instead of a table. A page that creates an XSLTProcessor in a script loses that class and the script fails at that point. Nothing in your XML data is lost, and nothing about how crawlers read it changes.

What to do

1. Check your sitemap and feed addresses to see which ones use XSLT.
2. For each one choose: remove the line, swap it for a CSS stylesheet, render HTML at build time, or add the polyfill.
3. For script code that uses XSLTProcessor, run the transform on the server, or load the polyfill.

What the removal does and does not affect

Think of two audiences. People who open the XML address in a browser lose the styled view. Software that downloads the XML, such as search engine sitemap fetchers and feed readers, never ran the stylesheet and keeps working. The sitemap or feed remains valid XML either way, so the data you publish is unchanged. This is general information; confirm with the documentation of any tool you depend on.

Finding XSLT use with the Reporting API

Chrome emits a deprecation report with the id XSLT when a page uses it. To collect these reports in a page you control:

new ReportingObserver((reports) => {
  for (const r of reports) {
    if (r.body.id === 'XSLT') console.log('XSLT used:', r.body.message, r.body.sourceFile, r.body.lineNumber);
  }
}, { types: ['deprecation'], buffered: true }).observe();

For files served as raw XML, use the checker, since there is no page script to observe. Our method section explains exactly what it looks at and what it cannot see.

Migration options at a glance

• Render HTML at build time:xsltproc -o sitemap.html sitemap.xsl sitemap.xml, then publish the HTML next to the XML.
• Polyfill: self-host xslt-polyfill.min.js (BSD-3-Clause, npm xslt-polyfill) and add <script src="xslt-polyfill.min.js" xmlns="http://www.w3.org/1999/xhtml"></script> inside the XML root.
• CSS: swap the line for <?xml-stylesheet type="text/css" href="/style.css"?>.
• Feeds: advertise them with <link rel="alternate" type="application/rss+xml" href="/feed.xml"> in your HTML pages.
• Script code: JSON with client-side rendering, or SaxonJS for XSLT 3.0.

Snippets and trade-offs for each are in the migration section on the home page.

Source

the official Chrome page on deprecating XSLT. This site is not run by the Chrome team and does not speak for it. Dates can change; check the official page before you plan around them.