Google’s Mason Freed proposes eliminating XSLT browser support, directly threatening RSS feed display and podcast industry infrastructure that relies on XML styling for content distribution.

Google Pac-Man consuming RSS feeds and XML technologies, illustrating browser vendor attack on open web standards Google engineer Mason Freed has initiated a formal proposal to remove XSLT (Extensible Stylesheet Language Transformations) support from web browsers, threatening the technical foundation that enables RSS feeds to display attractively in browsers. The proposal, submitted through the Web Hypertext Application Technology Working Group (WHATWG) this month, directly impacts the podcast industry and content syndication infrastructure that millions of publishers rely upon for automated content distribution.

According to the WHATWG Github issue #11523, Freed characterizes XSLT as a “niche, rarely-used feature” despite immediate pushback from developers highlighting extensive RSS feed usage. Dave Jones, representing podcast hosting companies, noted that “XSLT is extensively used by podcast hosting companies to beautify their raw feeds,” pointing to Buzzsprout’s implementation as a prominent example. The BBC also maintains XSLT styling for their news RSS feeds, demonstrating continued adoption by major media organizations.

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The timing proves particularly significant as RSS feeds experience renewed adoption following user migration away from centralized social media platforms. Industry observers estimate over 500 million WordPress websites automatically generate RSS feeds, while the entire podcast ecosystem depends on RSS XML for content distribution to platforms including Apple Podcasts, Spotify, and Google Podcasts. Removing XSLT support would force these feeds to display as raw XML code, significantly degrading user experience for direct feed access.

The XSLT removal proposal specifically threatens RSS feed functionality, which industry professionals immediately recognized as the technology’s primary remaining use case. When questioned about RSS feed display, Freed acknowledged this represents “the largest source of current usage” but suggested his WebAssembly-based polyfill could provide replacement functionality. However, polyfill solutions require JavaScript execution and additional resource loading, contradicting RSS feeds’ design principles of simplicity and universal accessibility.

Podcast hosting companies emerged as vocal opponents of the proposal, with representatives noting extensive XSLT implementation across the industry. Buzzsprout’s RSS feeds exemplify sophisticated XSLT styling that transforms raw XML into readable, branded content when accessed directly through browsers. This functionality proves essential for content verification, debugging, and direct subscriber access without requiring dedicated feed reader applications.

Major media organizations including the BBC maintain XSLT-styled RSS feeds, continuing practices established during RSS’s initial popularity surge in the early 2000s. Mary Hamilton noted the BBC’s continued XSLT usage and referenced the extensive 2013 discussion when Google first proposed XSLT removal. That earlier proposal generated opposition for five years, with developers continuing to submit counter-arguments as late as 2018.

The Podcast Standards Project, representing industry stakeholders including major hosting platforms and content creators, would face significant technical disruption from XSLT removal. RSS feeds serve as the universal distribution format enabling podcast content to reach multiple platforms simultaneously without platform-specific modifications. Degraded feed presentation could impact content discovery and subscriber acquisition for independent podcasters who lack resources for complex technical workarounds.

Industry coordination reveals browser vendor alignment

The WHATWG discussion demonstrates concerning coordination between major browser vendors, with Mozilla engineer “smaug” expressing immediate support for XSLT removal. WebKit representatives indicated “cautious support,” suggesting they would wait for another browser to implement removal first before following suit. This pattern reflects the oligopolistic nature of modern browser development, where a small number of companies control the fundamental technologies that power internet content distribution.

Anne van Kesteren from Mozilla proposed coordinating console warnings across browsers, indicating pre-planned deprecation strategies similar to those used for other web technologies. The discussion reveals browser vendors treating XSLT removal as inevitable rather than debatable, despite substantial developer opposition documented in the Github issue comments.

Firefox’s historical removal of RSS support in 2018 established precedent for browser vendors abandoning XML-based technologies despite user objections. Mozilla’s decision to give RSS feeds worse treatment than generic XML documents demonstrated willingness to actively obstruct feed functionality rather than simply maintaining existing capabilities. This aggressive stance toward RSS contradicted Mozilla’s stated mission of supporting an open web.

The coordination between Google and Mozilla on XSLT removal suggests broader strategic alignment on eliminating decentralized content distribution technologies. Critics argue this cooperation serves to consolidate web content around platform-controlled APIs and centralized services that provide greater data collection and monetization opportunities for major technology companies.

The XSLT removal proposal represents the latest phase in a systematic campaign against RSS feed infrastructure that began with Google Reader’s discontinuation in 2013. Google Reader served as the dominant RSS aggregation service, introducing millions of users to feed-based content consumption. Its closure forced users toward platform-specific social media feeds and centralized content discovery mechanisms controlled by major technology companies.

Mozilla’s 2018 decision to remove RSS support from Firefox marked another significant blow to feed infrastructure. Firefox actively prevents RSS feeds from displaying properly in browsers, treating them worse than generic XML documents. This hostile approach contradicts Mozilla’s stated commitment to supporting decentralized web technologies and user choice in content consumption.

Browser vendors consistently characterize RSS and XSLT as “legacy” technologies despite continued widespread usage across content publishing industries. The podcast ecosystem alone represents hundreds of millions of users consuming RSS-distributed content daily, while WordPress installations numbering over 500 million automatically generate RSS feeds for content syndication purposes.

Each removal of RSS-supporting infrastructure forces content creators toward platform-specific distribution channels. Without browser-based RSS display capabilities, users must install dedicated feed reader applications or rely on social media platforms for content discovery. This shift benefits centralized platforms that can collect user data and control content algorithmic distribution while reducing independent publisher reach and audience ownership.

Google’s XSLT removal proposal continues a documented pattern of actions specifically targeting RSS and XML-based content distribution infrastructure. The 2013 discontinuation of Google Reader eliminated the most popular RSS aggregation service, forcing millions of users toward social media feeds and centralized content platforms. This strategic decision preceded Google’s first XSLT removal proposal by several months, indicating coordinated efforts to undermine RSS ecosystem viability.

Subsequent actions reinforced this pattern. Google’s 2015 Fetch API introduction deliberately excluded XML document processing methods while providing dedicated JSON handling capabilities. The same year brought proposals to deprecate SMIL for SVG animation and remove the keygen cryptographic element, both technologies that enable decentralized content creation and secure communication outside platform-controlled environments.

Mozilla’s 2018 RSS support removal from Firefox represented successful coordination between browser vendors to eliminate feed functionality. Firefox now actively prevents RSS feeds from displaying properly, giving them worse treatment than generic XML documents. This aggressive approach contradicts Mozilla’s stated mission while supporting Google’s broader strategy to eliminate RSS infrastructure.

The pattern extends beyond technical removals to include policy changes that favor centralized platforms. Google’s search algorithm adjustments consistently prioritize large platform content over independent publisher RSS feeds. Social media platforms receive preferential treatment in search results while RSS-distributed content faces reduced visibility, creating economic pressure for publishers to abandon decentralized distribution methods.

Alternative solutions and industry response

Technical workarounds for potential XSLT removal include JavaScript-based XSLT processors like SaxonJS. These solutions provide similar functionality but with performance penalties and increased complexity. Browser extensions could potentially restore XSLT support, though extension API restrictions may limit effectiveness, particularly in Chrome’s Manifest V3 framework.

The broader developer community has begun documenting XSLT use cases and tutorials in response to removal threats. Multiple guides emerged focusing on RSS feed styling, data visualization applications, and template replacement scenarios. This grassroots documentation effort aims to demonstrate practical XSLT value beyond Google’s characterization of limited adoption.

Some technology professionals advocate for alternative browser adoption to maintain XML support. Browsers like Firefox, Safari, and Edge maintain independent development teams, though coordination through WHATWG often leads to feature convergence. Truly independent browsers like Pale Moon or emerging projects like Servo could preserve deprecated technologies, but market share limitations reduce their influence.

Industry observers note parallels between current XML restrictions and historical technology suppression efforts. Microsoft’s 1990s browser strategy involved embracing standard technologies, extending them with proprietary features, then abandoning standard compliance to lock users into Microsoft-specific solutions. Critics argue Google follows similar patterns with modern web standards.

Economic and strategic considerations

The removal proposal extends beyond technical considerations into broader economic territory. XML technologies enable cost-effective content publishing by reducing server processing requirements and simplifying development workflows. Publishers particularly benefit from XSLT’s ability to generate multiple output formats from single XML sources.

Podcast industry infrastructure depends entirely on RSS XML for content distribution. Apple Podcasts, Spotify, Google Podcasts, and other platforms consume RSS feeds to populate their directories. Any degradation in browser RSS support affects the broader podcast ecosystem, though dedicated applications typically maintain independent XML processing capabilities.

Content management system vendors face technical debt from browser feature removals. WordPress, Drupal, and other platforms must maintain compatibility across browser versions while adapting to deprecated functionality. These adaptation costs ultimately affect pricing and feature development for millions of websites.

Google’s broader privacy initiatives demonstrate similar patterns of replacing open standards with company-specific alternatives. Privacy Sandbox APIs provide Google-controlled replacements for industry-standard technologies. Publishers must adopt Google’s solutions or accept reduced functionality and revenue potential.

The marketing technology landscape increasingly reflects vendor consolidation around major platform ecosystems. Google’s advertising infrastructure, Meta’s social media APIs, and Amazon’s e-commerce tools create dependencies that limit independent innovation. Each removed standard technology reduces options for companies seeking vendor-neutral solutions.

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Timeline

• 2013: Google discontinues Google Reader RSS service eliminating dominant feed aggregator, proposes first XSLT removal targeting RSS feed styling, removes MathML support, closes XMPP federation
• 2015: WHATWG introduces Fetch API excluding XML processing methods while providing JSON support, Google proposes SMIL deprecationaffecting RSS feed enhancement capabilities
• 2018: Mozilla removes RSS support from Firefox version 64, actively preventing RSS feed display and treating them worse than generic XML documents
• 2019: Google announces Extension Manifest V3 changes that restrict RSS feed reader browser extensions
• 2023: Google renames Bard to Gemini overshadowing independent RSS-based protocol, proposes Web Environment Integrity API threatening RSS reader applications
• 2024: Chrome delays third-party cookie deprecation while maintaining pressure on RSS-based content distribution
• August 20, 2025: Google abandons cookie deprecation but launches new XSLT removal proposal through WHATWG targeting RSS feed display capabilities Subscribe PPC Land newsletter ✉️ for similar stories like this one. Receive the news every day in your inbox. Free of ads. 10 USD per year.

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Summary

Who: Google engineers led by Mason Freed propose XSLT removal through WHATWG, with Mozilla support from employee “smaug” and others including Tab Atkins Jr. and Domenic Denicola

What: Proposal to remove XSLT support from web browsers, eliminating ability to style XML documents including RSS feeds directly in browsers

When: WHATWG Github issue created August 20, 2025, following earlier Chromium issue, marking Google’s second major XSLT removal attempt since 2013

Where: Proposal submitted through WHATWG standards organization affecting Chrome, Firefox, Safari, and Edge browsers globally

Why: Google cites security vulnerabilities and resource constraints, though critics argue strategic motivation to eliminate decentralized web publishing technologies favoring Google alternatives

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PPC Land explains

XSLT (Extensible Stylesheet Language Transformations): A declarative programming language designed for transforming XML documents into other formats, primarily HTML for web browser display. XSLT operates through template matching and pattern-based transformations, enabling publishers to separate content structure from presentation logic. The technology processes XML data client-side, reducing server computational overhead while maintaining clean separation between data and styling. Current browser implementations support XSLT 1.0 from 1999, though more advanced versions like XSLT 2.0 and 3.0 remain unimplemented despite offering enhanced functionality including JSON processing capabilities.

XML (Extensible Markup Language): A markup standard that defines rules for encoding documents in both human-readable and machine-readable formats. XML serves as the foundation for numerous web technologies including RSS feeds, sitemaps, configuration files, and data exchange formats. The specification emphasizes structural validation, namespace support, and platform independence, making it valuable for content syndication and automated processing workflows. XML’s hierarchical structure enables complex data relationships while maintaining compatibility across different systems and programming languages.

RSS (Really Simple Syndication): A web feed format built on XML that enables automated content distribution and syndication across websites and applications, representing one of the most successful and enduring technologies for decentralized content publishing. RSS feeds contain structured metadata about articles, podcasts, and other content, allowing aggregation services and applications to track updates automatically without requiring users to manually visit multiple websites. The format powers the entire podcast industry infrastructure, with platforms like Apple Podcasts, Spotify, Google Podcasts, and hundreds of other applications consuming RSS feeds for content discovery and distribution. Over 500 million WordPress installations generate RSS feeds automatically, creating a vast network of syndicated content that operates independently of any single platform or company. News organizations, blogs, and content creators rely on RSS for audience retention and direct content distribution that bypasses social media algorithms and platform dependencies. The technology enables users to aggregate content from diverse sources into personalized reading experiences through feed readers, maintaining the original vision of an open, user-controlled web. RSS feeds also serve critical business functions including SEO through content syndication, automated marketing workflows, and integration with email marketing systems that convert feed content into newsletters. Google’s 2013 decision to shut down Google Reader significantly impacted RSS adoption, though recent years have seen renewed interest as users seek alternatives to centralized social media platforms and algorithmic content curation.

Google: The multinational technology corporation that developed and maintains the Chrome web browser, which holds dominant market share globally. Google’s influence extends through various web standards organizations, advertising technologies, and developer tools that shape internet infrastructure. The company’s strategic decisions regarding browser features directly impact millions of websites and applications worldwide. Through initiatives like Privacy Sandbox and deprecation proposals, Google significantly influences web technology evolution, often prioritizing its ecosystem of services and advertising revenue models.

Chrome: Google’s web browser launched in 2008, built on the open-source Chromium project and currently commanding over 60% global market share. Chrome’s technical decisions effectively set industry standards due to its widespread adoption among developers and consumers. The browser serves as the primary implementation platform for Google’s web technology initiatives, including Privacy Sandbox APIs and various deprecation proposals. Chrome’s development team actively participates in standards organizations like WHATWG, often driving adoption of technologies that align with Google’s broader business objectives.

WHATWG (Web Hypertext Application Technology Working Group): A standards organization formed in 2004 by browser vendors to accelerate web technology development outside traditional W3C processes. Originally founded by Apple, Mozilla, and Opera, WHATWG now includes Google as a dominant participant following Chrome’s market success. The organization develops HTML specifications and related technologies through collaborative processes, though critics argue Google’s influence has transformed WHATWG into a vehicle for promoting company-specific solutions rather than truly open standards development.

Browser: Software applications that interpret and display web content, serving as the primary interface between users and internet resources. Major browsers include Chrome, Firefox, Safari, and Edge, each implementing web standards with varying degrees of compliance and feature support. Browser vendors make technical decisions that directly impact website functionality, content accessibility, and developer workflows. The competitive dynamics between browser companies influence web standard adoption, with dominant browsers like Chrome effectively setting industry directions through feature implementations and deprecations.

Web standards: Technical specifications that define how internet technologies should function across different platforms and implementations. Organizations like W3C and WHATWG develop these standards through collaborative processes involving browser vendors, technology companies, and developer communities. Standards ensure interoperability between different systems while enabling innovation within defined frameworks. The standardization process balances competing interests including user privacy, developer convenience, performance optimization, and commercial objectives from major technology companies.

Publishers: Content creators and media organizations that produce and distribute information through websites, applications, and syndication channels. Publishers rely on various web technologies including RSS feeds, content management systems, and browser features to reach audiences effectively. Many publishers use XML-based workflows for content production, automated syndication, and multi-platform distribution. Browser feature deprecations directly impact publisher technical infrastructure, potentially requiring costly adaptations or reducing content accessibility for end users.

Marketing: Professional activities focused on promoting products, services, or content to target audiences through various digital channels. Digital marketing increasingly depends on web technologies including tracking systems, content syndication, analytics platforms, and browser APIs for campaign measurement and optimization. Browser vendor decisions regarding privacy controls, feature deprecations, and API availability directly impact marketing effectiveness and measurement capabilities. The industry must continually adapt to technological changes while maintaining compliance with evolving privacy regulations and platform requirements.