Google’s John Mueller says markdown pages serve a specific purpose for developer documentation sites but won’t help most websites, even as search becomes more agentic.
Mueller laid out his reasoning in a Bluesky thread. He was responding to a question from Lily Ray about why Google publishes LLMs.txt files and markdown pages, even though they aren’t needed for search performance.
His response focused mainly on markdown versions of developer documentation, not llms.txt as a standalone file.
Mueller wrote:
“The short answer is that it’s not done for search. There’s more to websites than just SEO :-).”
Mueller’s Discovery Vs. Functionality Framework
His reasoning focuses on two different website goals.
He called the first “discovery,” or being found via a search engine, and the second “functionality,” which helps users complete tasks on the page.
Mueller acknowledged the term wasn’t precise. “There’s probably a more accurate term for this,” he wrote in the thread.
He compared the distinction to calls to action on traditional pages, stating:
“You don’t ‘do them’ for SEO (to be found), but if you’re responsible for the website overall, ensuring a high ‘discovery rate’ (SEO) together with a high conversion rate is useful to justify your work.”
Why Developer Docs Are Different
On developers.google.com, he noted, markdown versions make sense.
Mueller said;
“AI coding has gotten very popular, and these coding systems can be (I think) efficient and accurate with the code they produce if they can easily read / parse reference material, such as developer documentation.”
He added that markdown can help AI systems “understand the context of the documentation they’re looking at, as well as a simplified version of the reference page.”
Mueller called this a workaround rather than a long-term need, adding:
“OF COURSE they can read HTML just fine, so this is imo more of a temporary crutch, perhaps to save some tokens.”
Non-Developer Sites Should Skip It
For everyone else, Mueller was direct, stating:
“For non-developer sites, I don’t think this makes much sense, even with more agentic traffic in the future. Making a markdown version of a shoe’s specs is not going to get you more sales (competitors appreciate it tho).”
He went further in a follow-up post, pushing back on the idea that sites should prepare for a future where agents drive more traffic.
Mueller added:
“And (I know, nobody reads this far), if you think this is important to prepare for when agents are everywhere: your site (all sites) have much more important things to do for SEO than to prepare for a potential future situation that may or may not come. Prioritize needs before dreams.”
Why This Matters
Mueller’s comments show a more detailed position than his earlier statements on the topic.
In February, Mueller called the idea of serving markdown pages to bots “a stupid idea.” His Bluesky comments carve out an exception for developer documentation while holding the line for every other type of site.
The thread also arrived on the same day we reported that Google’s guidance on llms.txt now depends on which product you ask. Google’s generative AI optimization guide says to skip llms.txt, while Lighthouse 13.3 added an experimental audit that checks for the file as part of agentic browsing readiness.
Looking Ahead
Mueller’s distinction between discovery and on-page functionality can help you evaluate whether agentic optimization is worth their time. The test is whether building for agents right now produces measurable results for a specific site.
The “prioritize needs before dreams” line captures a broader tension in the industry right now. Vendors have been promoting llms.txt and markdown optimization as emerging practices, but neither Google’s search documentation nor independent data support investing in these for non-developer sites.
Featured Image: kirill_makarov/Shutterstock
