XSLT Polyfill - XML to HTML Viewer & XSLTProcessor

Turns XML into readable HTML via its XSL stylesheet, offline: RSS feeds, sitemaps, e-invoices, local files. Plus an XSLT playground.

XSLT polyfill for Chrome: restore XML sitemaps, RSS feeds and XSL-styled pages, enable XSLTProcessor in web apps, and open local XML files. When an XML document references an XSL stylesheet, the extension transforms it into the readable HTML page you were meant to see. On November 17, 2026, Chrome is scheduled to stop applying XSLT stylesheets for most users. Feeds, sitemaps, invoices and reports that rely on XML plus a stylesheet may open as raw XML instead of formatted pages. This XSLT polyfill keeps turning that XML into HTML, directly in your browser tab, using libxslt compiled to WebAssembly and running in its own worker. It works offline, on your computer, and collects no data. WHAT YOU OPEN, WHAT YOU GET • RSS and Atom feeds: a feed that ships with its own XSL design opens as that designed page, not a wall of tags. • XML sitemaps: the readable sitemap table your SEO plugin's stylesheet builds comes back, so you can scan your URLs at a glance. • E-invoices (FatturaPA, UBL): an invoice that names its stylesheet opens formatted. One that doesn't opens as a searchable tree, and you can run it through the official stylesheet in Loom Lab. • XML files on your computer: open an .xml file in Chrome and the stylesheet it names, from the same folder or a subfolder, is applied. • Plain XML with no stylesheet: opens in the XML Viewer, a collapsible tree with search and an inspector that shows any node's XPath (one click to copy), attributes and namespace. • Web apps built on XSLTProcessor: turn the JavaScript API back on for the sites you choose, and only those. LOOM LAB: AN XSLT PLAYGROUND THAT STAYS OFFLINE Try a stylesheet before it goes live, or find out why one misbehaves. 1. Put your XML and your XSL side by side, or start from a built-in sample (news feed, sitemap, e-invoice, book list). 2. Watch the result update as you edit, or run it with Ctrl+Enter. 3. Set xsl:param values to try different inputs. 4. Read every xsl:message, error and timing in the console. Nothing is uploaded and there is nothing to sign in to, so client files and invoice data stay on your machine. TWO SHORTCUTS • Alt+Shift+X: switch between the rendered page and its XML source. • Alt+Shift+L: open Loom Lab. YOU CHOOSE WHERE IT RUNS • Pause the extension on any site from the toolbar panel. • Restore XSLTProcessor only on the sites that need it. Every other site is left alone. THE DATES • Before November 17, 2026: the XML Viewer and Loom Lab work right away. Until the cut-off, Chrome still styles XSLT pages itself, and the extension adds its source view and Lab to them. • November 17, 2026: Chrome is scheduled to stop applying XSLT for most users. From then on, the extension renders supported XML pages with their stylesheets, with nothing to set up. • August 17, 2027: the last exceptions (managed browsers with the enterprise policy, and sites in Google's origin trial) are scheduled to end too. FINE PRINT • This XSLT polyfill supports XSLT 1.0 using libxslt, the version traditionally supported by browsers. Stylesheets requiring XSLT 2.0 or 3.0 are not supported. • For local XML files, open the extension's details in chrome://extensions and enable "Allow access to file URLs".