Does Your Law Firm Need an llms.txt File?

If your firm has spoken to a marketing agency about AI search this year, there's a good chance "llms.txt" came up. It's often presented as the AI-era equivalent of a sitemap: add the file, and AI systems will understand your firm. Some firms are being charged to create one. Others have been told they're "invisible to AI" without it.

The question deserves a straight answer, because a law firm's marketing budget is finite, and time spent on a file nobody reads is time not spent on the things that matter. So here is what the primary sources actually say, what remains unknown, and what I'd do.

What is llms.txt?

llms.txt is a proposal, published by technologist Jeremy Howard in September 2024, for a plain-text Markdown file placed at the root of a website (yourfirm.com.au/llms.txt). The idea is to give AI systems a concise, curated summary of a site and a list of its most important links, so a language model doesn't have to wade through navigation, scripts and layout to find what matters.

A minimal file looks something like this:

# Example Lawyers
> A Brisbane family law firm advising on separation, property and parenting matters.

## Key pages
- [Family law services](https://example.com.au/family-law/)
- [Our lawyers](https://example.com.au/lawyers/)

It's a sensible idea, particularly for software documentation, which is where it started. The proposal's own site notes that companies including OpenAI, Anthropic and Google publish llms.txt files for their developer documentation. But publishing a file and reading other people's files when answering a user's question are different things. That distinction is where most of the confusion comes from.

What does Google say about llms.txt?

In May 2026 Google published a guide to optimising for its generative AI features in Search (AI Overviews and AI Mode), and clarified its llms.txt guidance in a June update. It is unusually direct.

On special files, the guide says: "You don't need to create new machine readable files, AI text files, markup, or Markdown to appear in Google Search." It adds that Google Search itself doesn't use them. If you maintain one for other services, Google says that's fine; it won't help or harm your visibility in Google Search.

The guide lists llms.txt alongside other tactics it treats as myths:

• llms.txt files and other "special" markup;
• "chunking" content into small pieces for AI;
• rewriting content just for AI systems;
• seeking inauthentic "mentions";
• overfocusing on structured data.

And it is clear about what does matter: to appear in its generative AI features, a page must be indexed and eligible to be shown in Google Search with a snippet. Google says its AI features are rooted in its core ranking and quality systems, which is why it describes optimising for them as, in effect, still SEO.

For a law firm, that's the most important point in this article. If a vendor's AI plan for Google starts with llms.txt rather than with whether your pages are indexed, eligible and genuinely useful, it starts in the wrong place.

Why does Chrome check for llms.txt, then?

This is the detail vendors often cite as proof the file matters. Google's Chrome team has added an experimental category to Lighthouse, its website-auditing tool, called Agentic Browsing. It checks how well a site is built for software agents that browse and act on the web. One of its checks, in Chrome's words, "checks for the presence of a machine-readable summary at the domain root", which is llms.txt.

Three points put that in context:

1. It's experimental. Chrome describes the category as experimental and based on proposed standards. It needs Chrome 150 or later to run.
2. It's not a search signal. The Lighthouse documentation makes no claim that llms.txt affects Google Search or AI Overviews, and Google's Search guidance says Search doesn't use it.
3. It measures agent readiness, not recommendation. It's a checklist for whether software could navigate your site, not evidence that any AI system recommends firms with the file.

So a "fail" on that one Lighthouse check isn't evidence your firm is invisible to AI. It's evidence an experimental audit didn't find a file.

What about ChatGPT, Claude and Perplexity?

Here the honest answer is: unknown. As at November 2026, I could find no public statement from OpenAI, Anthropic or Perplexity that their assistants read websites' llms.txt files when deciding what to cite or recommend. Their published crawler documentation focuses on robots.txt and named user agents. That isn't proof they never look at llms.txt, and it could change. But it means anyone claiming llms.txt will get your firm recommended by ChatGPT is making a claim the providers themselves haven't made.

So should your firm have one?

My view, which is interpretation rather than finding:

• If you already have one, keep it. It does no harm, and it may help some agents or tools later.
• If you don't, it's a low priority. It's a short file your web developer can create in under an hour. It shouldn't be a project, a retainer line or a reason to delay anything else.
• Don't pay a premium for it. If it appears on an invoice as "AI optimisation", ask what evidence supports the value.
• Keep it accurate if you have it. An llms.txt that lists old practice areas or departed lawyers is worse than none, because it's another place for stale information to live.

What actually matters instead

Google's guidance points to a less glamorous list. In 20 years of working with law firms, I've found the unglamorous list is usually the one that pays.

1. Indexable, snippet-eligible pages. Check that your key practice and lawyer pages are indexed and not blocked by noindex, nosnippet or robots rules.
2. Content that answers real client questions. Clear explanations of what you do, for whom and where, written for people, not for machines.
3. Accurate, consistent facts. Names, locations, practice areas and lawyers that match across your site, profiles and directories.
4. Deliberate crawler settings. Know what your robots.txt allows. (I've written separately about why your robots.txt is now an AI policy.)
5. Measurement. Use the generative AI reporting now in Search Console, and test repeatedly rather than trusting a single screenshot.

What we don't know

• Whether any AI assistant other than Google's will adopt llms.txt as an input, and when.
• Whether the Lighthouse Agentic Browsing category will become a stable standard, or change.
• Whether llms.txt affects AI agents that browse sites on a user's behalf. That's a plausible use, but I haven't seen evidence either way.

Confidence summary

Questions to ask a vendor selling llms.txt

1. Which AI systems have publicly said they use it?
2. What's your evidence that it changes whether a firm is cited or recommended?
3. How does it fit with Google's guidance that Search doesn't use it?
4. What are you fixing first: indexing, content, consistency or the file?

Frequently asked questions

Does llms.txt help law firms rank in Google? No. Google says Search doesn't use llms.txt and that having one neither helps nor harms visibility in Google Search.

Does llms.txt get my firm into AI Overviews or AI Mode? No. Google says pages need to be indexed and eligible for a snippet; no special files are required.

Do ChatGPT or Claude read llms.txt? As at November 2026, I couldn't find a public statement from OpenAI or Anthropic saying their assistants use websites' llms.txt files when answering users.

Is llms.txt bad for my website? No. It's harmless if accurate. Just don't treat it as an AI strategy.

Conclusion

llms.txt is a reasonable idea that has been oversold. For Google, the question is settled: it doesn't matter for Search. For other AI systems, there's no public evidence it does. The firms that do well in AI-mediated discovery won't be the ones with the neatest text file. They'll be the ones whose websites are accessible, accurate and genuinely useful, and who measure the result.

FirmRanker, the research platform I founded, is designed to test what actually changes whether AI systems discover and cite law firms. Its methodology explains how it measures that. At Practice Proof, we help firms prioritise the AI visibility work that matters. For a structured starting point, the AI Visibility Checklist covers the basics.

FirmRanker was founded by Dan Toombs. Practice Proof, also founded by Dan, provides digital and AI visibility services to law firms.