AudienceBench

beehiiv LLMs.txt: What's in the File, the 6,144-Character Cap, and When to Customize

beehiiv auto-generates llms.txt on paid plans. What goes in it, why busy newsletters hit the 6KB cap, what AI tools say about it, and when to customize.

By AudienceBench Editorial · Published · Pricing & docs checked

Every beehiiv website on a paid plan gets an llms.txt file at yourdomain.com/llms.txt. beehiiv builds it automatically from your publication, and you can replace it with your own version in SEO & sharing. It’s a short Markdown summary meant to help AI tools understand what your site is about.

This guide covers what beehiiv puts in the file, the 6,144-character limit (which matters more than it sounds), what AI companies actually say about llms.txt, and when it’s worth writing your own.

Our sources: beehiiv’s LLMs.txt, SEO settings, AI Crawl Control, and free trial help articles, beehiiv’s pricing page and its Aug 20, 2026 “AI Discovery” product update, the llms.txt proposal at llmstxt.org, Google Search Central’s AI features page, and the crawler docs from OpenAI, Anthropic, and Perplexity. We also read two live llms.txt files published by beehiiv sites. We checked all of them on October 28, 2026.

How we researched this: Everything below comes from beehiiv’s help center, pricing page, and product updates, the llms.txt spec, AI companies’ own docs, and two public llms.txt files we downloaded. We haven’t edited an llms.txt file in a beehiiv account, and we haven’t measured whether a custom file changes AI citations or traffic. So there are no screenshots or test results here. Where the docs leave gaps, we say so.

About our links: beehiiv links on this page are affiliate links (/go/beehiiv). That’s the only program we earn from here. Our recommendations would be the same either way.

The short version

QuestionAnswer (per today’s sources)
What is it?A Markdown file that summarizes your site for AI tools, following the llms.txt proposal
Which plans?All paid plans (Lite, Pro, Enterprise), and the 14-day Pro free trial. Not on Free
Which websites?Publications using beehiiv’s Website Builder
Where is it?yourdomain.com/llms.txt (public)
Where do you edit it?Website → Builder → Settings icon → Site settings → SEO & sharing, bottom of the page
What’s in the default?Generated from your posts, pages, authors, categories, products, and podcast episodes, up to 50 posts
Size limit6,144 characters (6KB). Auto-generated content over the limit is trimmed from the end (oldest posts first)
Can you customize it?Yes. Upload a .txt file or paste text, then Save llms.txt. It goes live right away
Can you undo it?Yes. Reset to default brings back the auto-generated file
Does it block or allow bots?No. That’s robots.txt, Discoverable on the web, or AI Crawl Control

Our suggestion: leave the default on if you publish often and mostly want AI tools to see recent posts. Write a short custom file if you have evergreen guides, a paid tier, or a back catalog that the default trims away. Don’t expect it to move Google traffic either way.

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What llms.txt is (and isn’t)

llms.txt is a proposal, not a web standard. It was published by Jeremy Howard in September 2024; the version at llmstxt.org is labeled “v2” and was last modified August 10, 2026. The idea: put a short Markdown file at /llms.txt that tells AI agents what your site is and links to the pages worth reading, so they don’t have to dig through navigation, ads, and scripts.

The spec’s format, in order:

  1. An H1 with the site name. This is the only required part
  2. A blockquote with a short summary
  3. Optional paragraphs or lists with more detail (no headings)
  4. Optional H2 sections that are lists of links: - [Name](url): optional note
  5. By convention, a section called Optional for links an agent can skip when it’s short on space

The spec says llms.txt is used “on demand, when an agent needs information about a topic while assisting a user,” mainly for inference rather than training. It’s also clear that llms.txt and robots.txt do different jobs: robots.txt says what bots may access, llms.txt gives them a map.

What AI companies say about it

This is the part most llms.txt articles skip.

  • Google says you don’t need it for Search. Its “AI features and your website” page states: “You don’t need to create new machine readable files, AI text files, or markup to appear in these features.” Google’s AI Overviews and AI Mode use normal Search indexing.
  • OpenAI and Perplexity both publish llms.txt files for their own developer docs (their crawler pages link to them). Their crawler documentation doesn’t say their bots read llms.txt on other websites.
  • Anthropic’s crawler help article, which covers ClaudeBot, Claude-User, and Claude-SearchBot, doesn’t mention llms.txt at all.
  • The llms.txt spec says “thousands of sites” publish one, that documentation platforms generate them automatically, and that Chrome’s Lighthouse checks for one in its agentic browsing audits.

So llms.txt is cheap to have and may help AI agents that look for it, but no major AI search provider we checked says it uses llms.txt to rank or cite pages. beehiiv’s own wording is careful too: it says the file “can improve how AI platforms index and represent your publication’s content.”

What beehiiv generates by default

beehiiv’s help article says the auto-generated file pulls from your publication data: posts, pages, authors, categories, products, and podcast episodes, for up to 50 posts in total. beehiiv’s Aug 20, 2026 product update calls it a “dynamic llms.txt file from your content” that you can customize “or put it on autopilot.”

To see what that looks like, we downloaded two public beehiiv llms.txt files on October 28, 2026: beehiiv’s own Product Updates publication (product.beehiiv.com) and Superhuman AI (superhuman.ai). Both use the same template:

# Product Updates

> The latest product drops on beehiiv.

This file provides information about Product Updates to help large language models understand and reference this publication's content.

## Posts
- [Podcasts that Pay](https://product.beehiiv.com/p/podcasts-that-pay): Bring your own sponsors, add programmatic ads, and let every episode earn.
- ...

What we noticed in those two files:

  • Title, blockquote, one sentence, then posts. The H1 is the publication name and the blockquote is its description, so your publication description in settings matters here.
  • Each post line has a short note that reads like the post’s subtitle (the help article doesn’t say where it comes from). Some posts get a bare link with no note.
  • Newest posts first.
  • Posts filled the whole file. The Product Updates file listed 42 posts at 6,116 bytes; Superhuman AI listed 31 posts at 5,976 bytes. Neither file had sections for pages, authors, categories, products, or podcast episodes.

That last point is the practical one. beehiiv says it trims from the end when the 6,144-character cap is hit. In both files we read, posts alone reached the cap well before 50, so nothing else was listed. Two files are a small sample, and a site with fewer or shorter posts may get the other sections. But if you post often or write long subtitles, expect your default file to be a list of your most recent posts and nothing else: no About page, no subscribe page, no paid-tier page, no evergreen guides from last year.

How to customize it

From beehiiv’s help article (updated Oct 1, 2026):

  1. Go to Website → Builder
  2. Click the Settings icon in the left panel, then Site settings
  3. Choose SEO & sharing and scroll to the LLMs.txt section at the bottom
  4. Click the link under Current llms.txt to view the live file
  5. Click Customize
  6. Either Upload .txt file or paste your content into the field (you can edit in the field either way)
  7. Click Save llms.txt. beehiiv says it’s live immediately

To go back, click Reset to default, then Reset in the confirmation box. That removes your custom content and restores the auto-generated file.

When a custom file is worth it

A custom file makes sense when the default list of recent posts doesn’t represent your site well:

  • You have evergreen guides. Point AI tools at your best explainers, not last week’s news recap.
  • You run a paid tier. Link the subscribe or upgrade page and say what paid readers get. The default file doesn’t include it in the samples we read.
  • Your subtitles are jokes or teasers. Write a one-line description per link that says what the page actually covers.
  • You want an “About” summary. The spec allows plain paragraphs after the blockquote: who writes it, how often it comes out, what topics it covers.

The default is fine when your newsletter is mostly timely news and you’d rather not maintain a file by hand.

The trade-off: beehiiv describes customizing as replacing the auto-generated content, and Reset as the way back. Its docs don’t say a custom file picks up new posts, so treat a custom file as static. Review it when you publish a major new guide.

A template that fits the cap

Here’s a skeleton in the spec’s format. Swap in your own pages and keep the whole file well under 6,144 characters:

# Your Newsletter Name

> One sentence on what you cover and who it's for.

Published weekly by Your Name. Free posts are public; paid subscribers get [what they get].

## Start here
- [About](https://yourdomain.com/about): Who writes this and why
- [Subscribe](https://yourdomain.com/subscribe): Free and paid options

## Best guides
- [Guide title](https://yourdomain.com/p/guide-slug): What the reader learns
- [Guide title](https://yourdomain.com/p/guide-slug-2): What the reader learns

## Recent posts
- [Post title](https://yourdomain.com/p/post-slug): One-line summary

## Optional
- [Archive](https://yourdomain.com/archive): Every past issue

Tips from the spec: use plain, specific language, give every link a short description, and test the file by giving only your llms.txt to an AI assistant and asking it questions about your site.

How it fits with beehiiv’s other AI settings

SettingPlansWhat it does
LLMs.txtAll paid plansA map of your site for AI tools. Doesn’t allow or block anything
Discoverable on the webAll plansOn by default. Off asks all search engines and AI crawlers not to index your site
Custom robots.txtPro, EnterpriseYour own robots.txt rules
AI Crawl ControlPro, Enterprise + custom domainBlocks specific AI and search crawlers, enforced by Cloudflare. See our AI Crawl Control guide
AEO settingsPro, EnterprisePer-post structured data. See our AEO settings guide

One thing to keep consistent: if you block an AI crawler or turn off Discoverable on the web, an llms.txt file won’t override that. The llms.txt spec says it complements robots.txt rather than replacing it.

What it costs

LLMs.txt is on every paid plan, so Lite is enough. Prices from beehiiv’s pricing page, checked October 28, 2026:

SubscribersLite (billed yearly / monthly)Pro (billed yearly / monthly)
1,000$49 / $59 per month$95 / $109 per month
2,500$69 / $79 per month$129 / $149 per month
5,000$95 / $109 per month$169 / $199 per month
10,000$119 / $139 per month$199 / $239 per month

beehiiv’s free trial is 14 days of Pro with no credit card, and the LLMs.txt article says the feature is available during the trial. The Free plan doesn’t get it. Full plan breakdown: beehiiv pricing explained.

Where beehiiv’s docs leave gaps

  • “Up to 50 posts” vs the cap. The 50-post figure is a ceiling. In the two public files we read, the 6KB cap cut the list at 31 and 42 posts, with no pages, authors, or products listed.
  • Paid or gated posts. The help article doesn’t say whether paywalled posts appear in the auto-generated file.
  • Custom files and new posts. Nothing says whether a custom file is ever refreshed. We assume it isn’t.
  • Advanced Website Builder. The LLMs.txt article’s notice mentions the Website Builder, and its path uses the Settings icon wording from Advanced builder articles. It doesn’t say whether both builders behave the same.
  • Downgrades. It doesn’t say what happens to the file if you drop to the Free plan.

Checklist

  • Confirm you’re on a paid plan (or the Pro trial) and using beehiiv’s Website Builder
  • Open yourdomain.com/llms.txt and read what’s there now
  • Check your publication description (it becomes the summary line)
  • Add clear subtitles to your important posts (in the files we read, the link notes look like subtitles)
  • If key pages are missing, Customize with a short file in the spec format, under 6,144 characters
  • Re-check the file after big launches; Reset to default if you stop maintaining it
  • Use AI Crawl Control or robots.txt, not llms.txt, to decide which bots get in

Our take

beehiiv’s llms.txt is a low-effort, low-stakes feature. The default works with no setup, and editing it takes a few minutes. Just keep expectations modest. Google says you don’t need it, and the AI companies we checked don’t say their crawlers use it. The most useful thing to know is the size cap: on an active newsletter, the default file is basically a list of your recent posts. If your best content is older or behind a paid tier, a short custom file is the better map. It’s not a reason to upgrade on its own, but if you’re already on Lite or Pro, it’s worth ten minutes.

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Sources

All sources below were checked October 28, 2026.