What is SubstackContentFetch?
SubstackContentFetch is a bot operated by Substack, a newsletter and subscription publishing platform. This bot fetches content from external websites to generate link previews, embed content, or aggregate information for newsletters published on the Substack platform. Agent Analytics can track when it visits your website.
Overview
| Operated By | Substack |
| Expected To Follow Robots.txt | No |
| Insights Last Updated | July 9, 2026 |
Category
Expected Behavior
SubstackContentFetch shows up within seconds of someone sharing one of your URLs, grabs the title, description, and preview image, and leaves. Expect one hit per share, no link following, and volume that tracks how much your content circulates. A widely shared link can mean thousands of fetches in an hour.
SubstackContentFetch's User Agent
| User Agent | SubstackContentFetch/1.0 (https://substack.com/) |
How To Block SubstackContentFetch With Robots.txt
Add this rule to your robots.txt file to request that SubstackContentFetch not access your website, or use Automatic Robots.txt to request the same of all fetchers at once. You can customize which pages are blocked by swapping out / for a different path.
User-agent: SubstackContentFetch # https://knownagents.com/agents/substackcontentfetch
Disallow: /SubstackContentFetch Global Insights
As of July 9, 2026, this data reflects agent visits measured across thousands of websites using Agent Analytics, combined with daily scans of the world's top 1000 websites and their robots.txt files.
Robots.txt Blocked Percentage
Country of Origin
Robots.txt Blocking Trend
0% of top websites block SubstackContentFetch in their robots.txt files.
Overall Fetcher Traffic
3.9% of all web traffic came from fetchers.
Top Visited Website Categories
The types of websites most frequently visited by SubstackContentFetch.
Frequently Asked Questions
Should I Block SubstackContentFetch?
No. SubstackContentFetch builds the link preview that appears when someone shares your page in a chat or social feed. Blocking it turns those shares into bare links with no title or image, which fewer people click. Its traffic normally follows sharing activity rather than a crawl schedule, so if it ever starts crawling at volume, rate limit it instead of blocking it. Almost none of the top websites we track have robots.txt rules for SubstackContentFetch right now.
Does SubstackContentFetch Respect Robots.txt?
No. SubstackContentFetch is not expected to honor robots.txt, so a disallow rule only states your preference. Enforce the block with firewall or server rules, then confirm in Agent Analytics that its requests actually stop.
Does SubstackContentFetch Access Private Content?
It cannot. SubstackContentFetch loads only the exact URL someone shared, reads the title, description, and preview image, and leaves. It has no credentials and does not follow links to other pages.
Why Is SubstackContentFetch Visiting My Website?
Someone shared a link to your page. SubstackContentFetch fetched it once to build the preview card, and every new share can trigger another fetch, so spikes mean your content is spreading.
How Can I Tell if SubstackContentFetch Is Visiting My Website?
Agent Analytics tracks SubstackContentFetch visits in real time alongside every other known AI agent, crawler, and scraper. You can also check your server logs for requests whose user agent string contains "SubstackContentFetch". Look for hits on single pages moments after someone shares a link, with no crawling afterward. Keep in mind that SubstackContentFetch doesn't publish a verification method, so any client can claim its user agent string and a log match is a hint rather than proof.