Google Warns Against Using Markdown for AI SEO Optimisation

Google’s John Mueller and Martin Splitt have advised caution when it comes to relying on markdown as a separate format for AI search optimisation. According to them, this approach may introduce unnecessary complexity into what is otherwise a straightforward publishing process.

Markdown and the User Experience Problem

Martin Splitt explained that markdown on its own is not well suited for delivering a strong user experience. He noted that traditional HTML pages allow for richer presentation, including layouts, images, styling and colour, all of which help make content easier to engage with.

In contrast, markdown is limited in how it can present information visually. While it can structure text, it lacks built-in support for design and layout features unless additional systems are introduced.

He pointed out that attempting to enhance markdown for users would effectively mean rebuilding many of the features already handled by web browsers. In his view, since HTML rendering is already a mature and well-established system, it makes more sense to continue using it rather than recreating similar functionality elsewhere.

Double Work for Publishers

Another concern raised was the idea of maintaining both HTML and markdown versions of the same content.

Splitt highlighted that this would effectively double the workload for website owners, who would need to manage two separate formats for each piece of content. This, he suggested, runs counter to the goal of simplifying publishing workflows.

Mueller agreed, noting that while some websites are poorly structured or difficult to use, the solution is not necessarily to create separate simplified versions for machines. Instead, the focus should remain on improving the quality of the main website itself.

He acknowledged the temptation to optimise differently for users and automated systems, but stressed that this can quickly lead to unnecessary duplication and maintenance issues.

The Importance of Visual Communication

Although not stated directly as a technical point, their comments also touched on the importance of visual presentation in communication.

Human users naturally respond strongly to visual cues such as layout, colour, imagery and structure. These elements help make information clearer and easier to process.

For this reason, well-designed HTML pages can often communicate content more effectively than plain text formats like markdown.

The Risks of Maintaining Parallel Versions

Both Mueller and Splitt also warned against the creation of separate content versions for different audiences or systems.

Mueller explained that once multiple versions of a page exist, complexity increases significantly. Website owners must ensure that each version remains functional and up to date, which can be difficult to manage at scale.

He also pointed out that while users will usually report broken pages, machine-facing versions such as those intended for AI systems may fail silently without anyone noticing. As a result, technical issues could persist for long periods without being detected.

Automated systems may also continue indexing incomplete or broken content if they still find readable text, even when the page is not functioning correctly.

Splitt added that this challenge is not new, referencing earlier attempts such as dynamic rendering. While those solutions were designed to help search engines process content more easily, they often introduced additional complexity and debugging difficulties in practice.

Key Takeaways

The main message from Google’s comments is that creating separate markdown versions of websites for AI systems is unlikely to be beneficial and may introduce unnecessary complications.

Rather than maintaining multiple formats of the same content, publishers are encouraged to focus on improving their existing HTML pages.

While markdown may appear simpler on the surface, it can lead to duplicated effort, maintenance challenges and potential inconsistencies between versions.

HTML also offers significant advantages for user experience, including structured layouts, visual design and navigational clarity, all of which help people engage with content more effectively.

Finally, Google’s comparison to past approaches like dynamic rendering suggests that maintaining separate machine-optimised versions of content has historically created more problems than it has solved, reinforcing the preference for a single, well-structured web experience.