Most advice about llms.txt and llms-full.txt assumes a website in one language. Plenty of Canadian businesses do not have that luxury. An Ottawa clinic, a Toronto accounting firm with Francophone clients, or a manufacturer selling into Quebec often runs English and French pages side by side, and the proposal behind these files says nothing about languages. We bring two decades of SEO work to this question, have practised AEO since the first AI answers appeared in search, and we work in both official languages every day. Here is how we would handle both files on a bilingual site, what the evidence says, and where your effort pays off more.
What are llms.txt and llms-full.txt, in plain terms?
llms.txt is a Markdown file at the root of your domain. Jeremy Howard of Answer.AI introduced the proposal on September 3, 2024, so that language models could find a site’s most useful pages without fighting through menus and scripts. It needs only an H1 with your name. Most files then add a blockquote summary, a few notes, and H2 headings with lists of links. A heading called “Optional” marks links that a tool may leave out. The proposal also floats the idea of Markdown (.md) versions of pages.
llms-full.txt takes a heavier approach: rather than linking out, it carries the whole text of your important pages in one document. According to Mintlify’s April 2025 post, the company built it in collaboration with its customer Anthropic before it became part of the wider proposal.
How do llms.txt and llms-full.txt compare?
| llms.txt | llms-full.txt | |
|---|---|---|
| In one line | A short, curated guide to your best pages | Your key pages’ full text, stitched into one file |
| Format | Markdown: H1 (required), summary blockquote, notes, H2 link lists | Markdown: page after page of body text |
| Usual size | Around 1 to 10 KB | Around 100 KB up to several MB |
| Origin | Proposed by Jeremy Howard, Answer.AI, September 2024 | Created by Mintlify with Anthropic, later added to the proposal |
| On a bilingual site | Two language sections fit easily in one small file | Doubles in size, and every French edit must be mirrored |
| Who benefits most | Any business wanting a tidy summary for AI tools | Software firms and organizations with large help centres |
Does the llms.txt proposal say anything about French and English?
No. It describes one file at the root of a site and does not mention languages, translations or regional versions. So every bilingual approach below is a judgment call, not a standard. Anyone who tells you there is an official “correct” way for a bilingual Canadian site is guessing.
With that said, these are the three realistic options:
| Option | How it works | Strengths | Weaknesses |
|---|---|---|---|
| A. One file, two language sections | A single /llms.txt with English and French H2 sections | Follows the proposal’s one-file-at-the-root model; easiest to maintain | A large site’s file gets long; the H1 and summary need both languages |
| B. Separate /fr/llms.txt | English file at the root, French file under the /fr/ folder | Mirrors how many bilingual sites split their URLs | A convention you would be inventing; nothing is documented as looking for it |
| C. English file that points to French pages | Root /llms.txt in English, with a section listing the French equivalents | Simple; keeps French URLs discoverable | Summary and notes exist in English only |
Our default for most Ontario businesses is option A. It keeps everything in the one place the proposal actually names, and a small or mid-size bilingual site rarely needs more than 20 or 30 links in total.
What does a bilingual llms.txt look like?
This example is for a fictional Ottawa physiotherapy clinic that serves patients in both languages:
# Rideau Physiotherapy / Physiothérapie Rideau
> Physiotherapy clinic in Ottawa, Ontario, serving patients in English and French.
> Clinique de physiothérapie à Ottawa (Ontario), services en français et en anglais.
Registered physiotherapists. Most insurance plans can be billed directly.
Physiothérapeutes autorisés. Facturation directe à la plupart des assureurs.
## English
- [Physiotherapy](https://www.example.ca/en/physiotherapy/): assessment and treatment plans
- [Concussion care](https://www.example.ca/en/concussion/): return-to-work and return-to-sport programs
- [Book an appointment](https://www.example.ca/en/book/): hours, location, parking
## Français
- [Physiothérapie](https://www.example.ca/fr/physiotherapie/): évaluation et plans de traitement
- [Commotions cérébrales](https://www.example.ca/fr/commotion/): retour au travail et au sport
- [Prendre rendez-vous](https://www.example.ca/fr/rendez-vous/): heures, adresse, stationnement
## Optional
- [Blog](https://www.example.ca/en/blog/)
- [Blogue](https://www.example.ca/fr/blogue/)A few details worth copying. The H1 carries both trade names, exactly as they appear on signage and the Google Business Profile. The summary and notes are written in both languages, not machine-translated afterward. The language sections are simply “English” and “Français”. The last heading stays as the English word “Optional”, because that exact label is the one the proposal defines; translating it to “Facultatif” would remove the one signal a tool might act on.
What about llms-full.txt on a bilingual site?
Here we are more cautious. Take a Toronto accounting firm with 30 English pages and 30 French pages. A full-text file would contain both sets, roughly doubling its size, and every time a tax deadline page changes in English, the French copy inside the file has to change too. If the two drift apart, you are publishing conflicting facts about your own firm.
For a firm like that, we would not build llms-full.txt at all. If you run bilingual software documentation or a large help centre, generate separate full-text files per language from your docs platform, link both from llms.txt, and never edit them by hand.
What does the evidence actually show?
Use is growing quickly. PPC Land reported in July 2026 that Originality.ai, which tracks more than 3 million sites, counted llms.txt on 4,088 sites in June 2025 and 36,120 in May 2026, an 8.8x increase. Sites with llms-full.txt went from 23 to 2,463 over the same period.
Being read is another story. The same report covers an Ahrefs study of server logs from 137,000 domains in May 2026: 97% of llms.txt files drew no requests at all. AI retrieval bots accounted for about 1.1% of the requests these files did get, and GPTBot was the most common named AI requester. We know of no Canadian or French-language breakdown, so we cannot tell you whether bilingual files fare any differently.
Google’s stance has not wavered. Its guide to generative AI features in Search, published in May 2026 and summarized by Search Engine Journal, describes optimizing for AI Overviews and AI Mode as still SEO and says llms.txt is not needed. In June 2026, Google called the file’s effect “purely speculative”, while suggesting you create one if a platform that genuinely brings you customers requests it. Chrome’s Lighthouse 13.3, though, now includes an experimental Agentic Browsing audit looking for llms.txt, which is why Search Engine Journal observed that Google’s guidance shifts depending on the product. That audit concerns browser agents, not Search rankings.
OpenAI, Anthropic and Perplexity each publish llms.txt files for their developer documentation. None has publicly stated that its crawlers rely on llms.txt to choose search results or citations.
What matters more for AI visibility in Canada?
Whether a buyer in Mississauga types in English or a patient in Ottawa asks in French, the same six platforms decide who gets named: ChatGPT, Gemini, Perplexity, Microsoft Copilot, and Google’s AI Overviews and AI Mode. These are the factors we see making the difference:
- French pages that stand on their own. Separate, indexable URLs for each language, linked with hreflang, with French text written for French-speaking readers rather than a rough translation.
- Indexing in Google and Bing. Google’s AI features and Gemini lean on Google’s own index, while Copilot’s answers rest on Bing. Check both Search Console and Bing Webmaster Tools, and use IndexNow where your CMS allows it.
- Open doors for search crawlers. OpenAI’s documentation says a site that shuts out OAI-SearchBot will not appear in ChatGPT search answers; GPTBot, its training crawler, is a separate setting. Allow PerplexityBot too, since Perplexity retrieves pages live and cites them by number.
- Identical business facts in both languages. Name, address, phone, hours and services should match across both versions of your site, your Google Business Profile and Canadian directories.
- Mentions from trusted Canadian sources. Professional associations, local and French-language media, chambers of commerce and regulator listings.
- Direct answers near the top of the page. In both languages, state the answer before the background.
Checklist for a bilingual llms.txt
- Confirm both language versions are indexed and linked with hreflang.
- Check robots.txt, your firewall and CDN for blocks on OAI-SearchBot, PerplexityBot, Googlebot and Bingbot.
- Choose one approach (A, B or C above) and document why.
- Write the H1 with your bilingual trade name and a summary in both languages.
- List English and French pages in their own sections, using full URLs that return a 200 status.
- Keep the “Optional” heading in English.
- Skip llms-full.txt unless you have bilingual documentation generated automatically.
- Review the file whenever either language version of a key page changes.
- Revisit your access logs in 60 to 90 days to see what, if anything, fetched it.
Mistakes to avoid on bilingual sites
- Machine-translating the file. If the French summary reads awkwardly, it reflects on your brand the moment it is quoted.
- Listing only English pages. French URLs left out of the file and thin on the site send a signal that your French service is an afterthought.
- Different facts in each language. Old hours on the French page, new hours on the English one. We see this often, and AI tools repeat whichever version they find.
- Treating llms.txt as a replacement for hreflang. It is not one. Search engines rely on hreflang and properly linked URLs to match language versions.
- Paying extra for a “bilingual llms.txt package”. It is a small text file, not a strategy.
Our verdict
For a bilingual Canadian business, a single llms.txt with clear English and French sections is a sensible, low-cost addition. Skip llms-full.txt unless you publish documentation in both languages and can generate it automatically. Neither file has shown a measurable effect on AI visibility, and Google says plainly that you can do without them. What does move the needle is the groundwork: properly indexed French and English pages, open access for AI search crawlers, consistent facts and credible mentions. That is where Answer Engine Canada puts its effort, in both languages, and where we would put yours.