Does turning on the Substack AI training block remove me from ChatGPT or Perplexity answers?

Substack does not say exactly how the signal is sent or which crawlers it covers. Its help article says the setting asks AI tools not to train on your content, applies only to tools that respect it, and may limit discoverability in tools that return AI-generated results. If being cited by AI search matters to you, weigh that before switching it on.

Can I edit robots.txt on Substack?

No. Substack generates robots.txt for every publication and offers no editor. You influence crawling only through settings such as the AI training toggle and making the publication private.

Do private Substack publications show up in search?

Only the Welcome page. Substack says it may still appear in web search, but no posts from a private publication are indexed.

AI search readiness · Website builders and CMSs

Substack SEO and AI search: the AI training toggle, sitemaps, robots

Substack runs robots.txt, sitemaps and structured data for you, and none of the files are editable. Your levers are settings: a Privacy toggle that tells AI tools not to train on your posts, the post URL and SEO options on each draft, your subdomain or custom domain, and inbound links. Substack says some SEO features, including sitemaps and Search Console verification, become available as a publication grows.

Edit robots.txt: NoManaged by Substack. No setting to edit it; the AI training and privacy toggles are the only controls documented.
XML sitemap: PartlySubstack publications serve sitemap.xml and news_sitemap.xml, but Substack says sitemap features and Search Console verification become available as a publication grows. /sitemap.xml
llms.txt: NoYou cannot upload files to a Substack publication; /llms.txt returns 404 on Substack's own publication.
AI crawlers: A Privacy setting, "Tell AI tools not to train their models on your content", signals AI tools such as ChatGPT, Claude and Gemini not to train on your posts. It only works with tools that respect it, and Substack warns it may limit discoverability in AI-generated results.
Structured data: Automatic. Substack post pages include NewsArticle and BreadcrumbList JSON-LD with the publisher as an Organization. There is no option to add your own.

What Substack controls, and what you control

Substack is a hosted publishing platform, so the technical SEO files are not yours to edit. On Substack's own publication, on.substack.com/robots.txt disallows app paths such as /publish, /sign-in, /subscribe, /action/ and comment permalinks, blocks one SEO bot (BLEXBot) entirely, and lists two sitemaps: /sitemap.xml and /news_sitemap.xml. There is no field to change any of this.

What you do control:

Subdomain. Substack recommends using your name (or an existing brand readers already search for). Change it in Settings > Danger Zone > Change subdomain.
Post URL and SEO options. On a draft, open Settings at the bottom, expand SEO Options, and set the Post Url. Slugs take lower-case letters, numbers and dashes, 2 to 48 characters.
Links. Substack's own SEO advice is that ranking depends on creator credibility and inbound links, so link the publication from your site and social bios.

The Block AI training toggle

Go to your publication's Settings, scroll to Privacy, and switch on Tell AI tools not to train their models on your content (a newer help article calls it the Block AI training toggle and says it signals to external AI crawlers). Substack says this tells AI tools such as ChatGPT, Claude and Gemini not to train on your published content.

Two caveats from Substack itself: it only applies to tools that respect the setting, and it may limit your publication's discoverability in tools and search engines that return AI-generated results. Substack does not document which user agents it names or whether it writes the rule to robots.txt. Training crawlers like GPTBot are separate from search crawlers like OAI-SearchBot, so after switching it on, run your publication through the robots.txt checker to see which bots are actually blocked.

Sitemaps and Search Console

Substack's SEO article says some features, including sitemaps and Google Search Console verification, become available as a publication grows; publishing regularly, growing your subscriber list and enabling paid subscriptions help make them available. Until then, Substack handles discovery. Once verification is available, submit /sitemap.xml for your subdomain or custom domain.

A private publication is mostly invisible: Substack says its Welcome page may appear in search, but no posts are indexed.

llms.txt and structured data

llms.txt is not possible: there is no way to upload files, and /llms.txt returns a 404 on Substack's own publication. Structured data is automatic. Post pages carry NewsArticle and BreadcrumbList JSON-LD with headline, description, images and the publication as an Organization, so a clear headline and subtitle on every post are what feed it.

Check your Substack site

Paste your domain to see which AI crawlers your live robots.txt lets in.

robots.txt checker

Test your robots.txt against every AI crawler

robots.txt generator

Allow AI search, block trainingStay citable in ChatGPT, Claude, Perplexity, Gemini and Copilot answers while opting out of model training.Allow everythingEvery crawler may read every public page. The default when there is no robots.txt.Block all AI crawlersKeep Google and Bing search, block every AI crawler. AI answers will rarely cite or recommend the site.

Sitemap URLPrivate paths (one per line)

robots.txt

# robots.txt generated with https://www.getpicked.app/tools/robots-txt-checker
# Preset: Allow AI search, block training

User-agent: *
Allow: /

# Model training crawlers
User-agent: GPTBot
User-agent: ClaudeBot
User-agent: Google-Extended
User-agent: Applebot-Extended
User-agent: Meta-ExternalAgent
User-agent: Amazonbot
User-agent: CCBot
User-agent: Bytespider
Disallow: /

Questions

Does turning on the Substack AI training block remove me from ChatGPT or Perplexity answers?: Substack does not say exactly how the signal is sent or which crawlers it covers. Its help article says the setting asks AI tools not to train on your content, applies only to tools that respect it, and may limit discoverability in tools that return AI-generated results. If being cited by AI search matters to you, weigh that before switching it on.
Can I edit robots.txt on Substack?: No. Substack generates robots.txt for every publication and offers no editor. You influence crawling only through settings such as the AI training toggle and making the publication private.
Does Substack have a sitemap?: Publications serve /sitemap.xml and /news_sitemap.xml, both listed in robots.txt. Substack's SEO article says sitemap features and Google Search Console verification become available as a publication grows, helped by publishing regularly, growing subscribers and enabling paid subscriptions.
Do private Substack publications show up in search?: Only the Welcome page. Substack says it may still appear in web search, but no posts from a private publication are indexed.

Other website builders and cmss

Sources

Checked against these pages on 2026-10-19. Operators change their crawlers; check the source before relying on a detail.