Substack Privacy Analysis

Substack currently has a not rated privacy classification on Noizz. Users concerned about data privacy should carefully evaluate Substack's data practices and consider privacy-focused alternatives.

Ask two separate questions about Substack rather than one: is data encrypted while travelling, and is it encrypted while stored, and if stored, who holds the keys. The last part is the one that matters most and the one marketing pages are vaguest about. Confirm it in the product's own security documentation before treating anything sensitive as protected.

Read what Substack commits to in writing, not what the homepage implies: what is collected, how long it is kept, and whether it is used to train or improve anything. The current policy on the product's own site is the authority, and policies are revised more often than reviews are updated.

Your data rarely stops with Substack alone. Analytics, infrastructure, and support tooling behind it can each hold some of it, which is why the subprocessor or third-party list is worth finding, it is usually more revealing than the privacy policy summary. If that list is not published anywhere, treat the absence itself as the answer.

The honest verdict on Substack is less a score than a matching exercise. It is a marketing-seo product with a freemium model, and none of that decides anything until you set it against the work you actually do. Where its newsletter-platform and paid-subscriptions emphasis overlaps your priorities, expect it to pull its weight; where it does not, no amount of polish elsewhere will close the distance. The cheapest way to find out is unchanged in 2026: take whatever no-cost path it offers, bring one real task, and let the result argue for or against it.