Substack has quietly become one of the largest publishing platforms on the internet — millions of newsletters, from solo creators to journalists who left traditional media entirely, all running on the same infrastructure. What most Substack writers don’t realize is that every single publication on the platform already has a fully working RSS feed, sitting there unused, ready to turn every new post into an automatic social media announcement the moment it goes out to subscribers.
This guide covers exactly how to find your Substack RSS feed, what it contains, the one thing that trips people up (custom domains), and how to connect it to an auto-posting tool so new issues reach Facebook, X, LinkedIn, Pinterest, and other networks without you touching a scheduler.
Every Substack publication’s feed follows the exact same predictable pattern: take your publication’s web address and add /feed to the end of it. If your newsletter lives at https://yourname.substack.com, your feed is at:
https://yourname.substack.com/feed
Open that URL directly in a browser and you’ll see raw RSS XML — every published post, in order, with its title, a description or excerpt, a link back to the full post, and a publish date. No setting to toggle, no dashboard option to enable. Substack generates this automatically for every publication that exists on the platform, and it always has, going back to the platform’s earliest days.
A trailing slash makes no difference — both /feed and /feed/ return the identical XML. New posts typically show up in the feed within 15 to 30 minutes of publishing, which is fast enough that most auto-posting schedules checking every 15 minutes or slower will never notice a delay.
If your Substack publication uses a custom domain (something like news.yourbrand.com instead of a .substack.com address, a common setup for established writers and brands who moved their newsletter onto their own domain), the standard /feed pattern can sometimes 404 depending on how the domain is configured. When that happens, the fix is simple: open your publication’s actual homepage in a browser, add /feed to whatever that homepage URL is, and load it. If you see raw XML content rather than an error page, that’s your working feed URL — just use it exactly as it appears, custom domain and all. The underlying feed still exists; it’s just served from wherever your specific domain currently points.
Each item in a Substack feed carries the same fields a well-formed RSS 2.0 feed is supposed to have: a title, a link back to the post on Substack (or your custom domain), a publish date, and a description field that typically contains either the post’s excerpt or, depending on the publication’s settings, the full post content. Free posts generally appear with their complete content in the feed; posts marked paid-subscriber-only usually appear with just a preview or excerpt, with the full text staying behind Substack’s paywall — the feed respects the same access restrictions the web version does, rather than leaking paid content to anyone who finds the raw feed URL.
This matters directly for auto-posting: a social post built from the feed’s description field will pull whatever that field actually contains, so a paid-only post will generate a social announcement built from its preview text (a natural teaser, not a full content leak), while a free post’s social announcement can draw on the complete piece if your posting tool’s message format is set up that way.
Once you’ve confirmed your feed URL loads correctly, connecting it to PostRSS follows the same pattern as any other RSS source:
https://yourname.substack.com/feed, or your custom-domain equivalent) as a source.From that point on, every new issue you publish on Substack triggers a matching post on each connected network automatically, without a second login or a separate scheduling step.
Newsletter writers face a specific distribution problem blog authors don’t: your actual audience only ever sees a new post if they open the email, and open rates — even for engaged lists — rarely clear 40–50%. A newsletter’s social presence isn’t a nice-to-have discovery channel the way it might be for a general blog; it’s often the primary way non-subscribers ever encounter your writing at all, and frequently the mechanism that converts a social follower into an email subscriber in the first place. Automating that social announcement means every issue gets its full potential reach outside the inbox, consistently, whether you remember to manually post that day or not.
Writers who run more than one Substack (a main newsletter plus a smaller side project, or a publication with multiple named sections each generating their own feed) can add each publication’s feed as its own separate source, pointed at whichever destinations make sense for that specific audience — no need to funnel everything through one undifferentiated social presence if your publications actually serve different readers.
Substack has, over the past couple of years, built its own in-network tools for spreading a publication’s reach — “Notes” (a short-form, Twitter-like feed inside the Substack app), cross-post arrangements between publications, and recommendation widgets that surface one newsletter to another’s subscribers. These are genuinely useful, but they all share one limitation: they only reach people who are already inside the Substack ecosystem. Someone who has never opened the Substack app, and never will, is never going to see a Note, a cross-post, or a recommendation widget no matter how well it performs internally.
RSS-based auto-posting solves a different problem entirely: it reaches your audience wherever they already spend their time — Facebook, X, LinkedIn, Pinterest — platforms with billions of users who have no relationship with Substack as a platform at all and never will. The two approaches aren’t competitors; they’re complementary. Substack’s own tools grow your reach within an ecosystem of other newsletter readers, which is valuable audience-acquisition territory. RSS auto-posting grows your reach among people who don’t read newsletters yet, or who discover new writers exclusively through the social platforms they already open forty times a day. A serious distribution strategy for a newsletter in 2026 uses both, not one instead of the other.
| Substack Notes / Cross-Post | RSS Auto-Posting (PostRSS) | |
|---|---|---|
| Reaches non-Substack users? | No — stays inside the Substack app/ecosystem | Yes — posts directly to Facebook, X, LinkedIn, Pinterest and more |
| Setup required per post | Manual, per post, inside Substack’s own interface | One-time source setup, then fully automatic |
| Works for other platforms too? | No — Substack-specific | Yes — the same setup pattern works for any RSS source, not just Substack |
| Best for | Growing within the newsletter-reader ecosystem | Reaching people who don’t already read newsletters |
One setup choice worth getting right from the start: most message-format options let you choose between posting just the item title, the title plus a short description, or a longer combination. For a newsletter that regularly runs 1,500+ words, posting the entire piece as the body text of a Facebook or LinkedIn post rarely performs well — long-form text buried in a social post tends to get truncated by the platform itself, and it removes the actual reason for someone to click through to Substack (and, ideally, subscribe). A title-plus-short-excerpt format that ends with a clear reason to click usually outperforms a full-text dump, and it’s a one-time setting, not something you manage per post.
If your Substack feed URL loads but shows no items, or items that are older than your latest post, the most common causes are: the feed briefly caching an older version right after a very recent publish (usually resolves itself within the normal 15–30 minute window), a custom domain pointing somewhere unexpected (revisit the homepage-first method described above), or — rarely — a publication that’s been set to fully private, which can restrict feed access the same way it restricts the web page itself. If the feed loads correctly in a browser but an auto-posting tool reports it as empty or invalid, that’s usually a sign the tool is pointed at a slightly different URL than the one that actually works in a browser — copy the URL directly from the address bar rather than retyping it.
No. The feed exists automatically for every Substack publication at the standard /feed URL pattern — there’s no setting to find or toggle in your publication’s dashboard.
No. Substack’s feed respects the same paywall the web version enforces — paid posts typically appear in the feed with a preview or excerpt only, not the full locked content.
Load your publication’s actual homepage first, then add /feed to whatever that specific URL is (custom domain included) rather than assuming the generic yourname.substack.com/feed pattern applies. If you see XML instead of an error, that’s the correct feed URL for your setup.
Typically within 15 to 30 minutes of publishing — fast enough that most standard auto-posting check intervals won’t introduce a noticeable delay between your send and your social post.
Yes — add each publication’s feed as its own separate source, each pointed at whichever destinations make sense for that specific newsletter’s audience.
The setup is identical regardless of destination — PostRSS reads the same feed and posts to whichever networks you’ve connected, though each platform’s own posting limitations (documented per-network in PostRSS’s guides) still apply the same way they would for any other RSS source.
Not every social network suits every newsletter equally. A text-heavy political or business newsletter tends to land well on X and LinkedIn, where short-form commentary and professional context both perform. A visually-driven newsletter (recipes, design, fashion, travel) tends to find a second life on Pinterest, where the pin’s linked traffic can flow back to Substack for months after the original post, far longer than a single social post’s typical lifespan. A newsletter aimed at a local or community audience often does better funneled through a Facebook Page, where algorithmic reach still favors page content shared consistently over time. There’s no requirement to pick just one — PostRSS can point the same Substack feed at several destinations simultaneously, each with its own schedule and message format, so a single new issue can go out as a short teaser on X, a fuller excerpt on LinkedIn, and a visual pin on Pinterest, all from the one publish action on Substack.
Every Substack publication already has a working, fully automatic RSS feed at a completely predictable URL — no plugin, no settings toggle, nothing to enable. For newsletter writers whose actual reach depends heavily on getting new issues in front of people who haven’t subscribed yet, connecting that existing feed to an auto-posting tool closes a real gap: instead of remembering to manually share every issue across every network, every new post reaches your social audiences automatically, within minutes of hitting publish.