Substack Scraper - Newsletters, Authors & Post Performance

Extract newsletter data from Substack: who runs a publication, how large and how expensive it is, and how its individual posts perform. Search a topic or point the actor at specific publication URLs.

What you get

Per publication

Field	Example
publicationName, publicationSlug, publicationUrl	the newsletter
authorName, authorBio	who writes it
subscriberCount	audience size where published
subscriptionPrice	paid tier price
isPaid	whether it has a paid tier
postCount	how much has been published

Per post

Field	Example
postTitle, postUrl	the article
postDate	publication date
postType	newsletter, podcast, thread
wordCount	length
likes, commentsCount	engagement

Search filters

• searchQuery - topic to find publications in, e.g. technology, finance, parenting
• category - restrict to a Substack category
• publicationUrls - scrape specific newsletters directly
• includePosts - also collect individual posts
• maxPublications - how many newsletters to process
• maxPostsPerPublication - how deep to go per newsletter

Example input

{
  "searchQuery": "technology",
  "includePosts": true,
  "maxPublications": 10,
  "maxPostsPerPublication": 20
}

Use cases

• Sponsorship and advertising prospecting - find newsletters in a niche with a real audience, and see what a paid subscription costs as a proxy for their rates
• Media research - map who the influential writers in a topic are, with their bios
• Content strategy benchmarking - compare word counts, posting frequency and engagement across competitors
• Influencer and partner sourcing - identify writers whose audience overlaps yours
• Competitive intelligence - watch what a rival publication covers and which posts land
• Market sizing - estimate how much paid readership a category supports

Why newsletter data is hard to get elsewhere

Newsletters are deliberately outside the social platforms, so there is no public API and no follower graph to query. Substack is the exception that leaks useful signals: subscriber counts, paid tier prices and per-post engagement are all visible on the public site. That combination is what makes sponsorship rates estimable at all.

Notes

• subscriberCount appears only when the author chooses to display it; many hide it and those rows stay empty.
• likes and commentsCount are snapshots, so recent posts will be under-counted relative to older ones.
• wordCount is derived from the public post body. Paywalled posts expose only their preview, so their word count is a floor, not the full length.
• Use publicationUrls when you already know the newsletters you care about; it is faster and more reliable than searching.