Cross-Post Substack to LinkedIn, Medium and X (2026)

The problem

Writers want each Substack post to reach the people who follow them elsewhere, especially on LinkedIn. Some have built their own pipelines:

"Every time I post an X article, claude takes it and posts it in beehiiv, substack, medium, linkedin and my personal blog" (@AunySillyMe, X, 2026-10-16)

Others don't trust the way those pipelines work:

"agree, browser automation for this stuff feels like a ticking time bomb" (r/MarketingAutomation, 2026-09-27)

The good news is that cross-posting out of Substack doesn't need a login, a bot or a private API. Every publication has a public RSS feed, and LinkedIn, Medium and X each have an official way in. This guide shows the native options first, then no-code tools, then a tested script.

What can Substack do natively?

As of October 2026, Substack has three features that touch this job. None of them publishes a written post to LinkedIn for you.

• Video clips to LinkedIn. If you connect LinkedIn under Settings → Connected accounts, Substack can upload up to two auto-generated clips from a video post when you publish it. The connection is tied to your profile, not the publication, so Substack suggests a shared LinkedIn account for multi-author publications (Substack Help).
• Social preview. In the post editor, Settings → Social preview controls the title, text and image LinkedIn and X show when someone shares your link. Substack recommends images of at least 1200 × 630 (Substack Help).
• "Cross post" is something else. Substack's Cross post button sends another publication's free post to your subscribers. It works only inside Substack (Substack Help).

After you share, check what worked. Each post's page lists traffic sources, including "Popular sites" such as the social network a reader clicked from (Substack Help).

How do I cross-post Substack to LinkedIn automatically?

Start from your feed. Substack's help centre gives the address as https://your.substack.com/feed (Substack Help); with a custom domain, use https://yourdomain.com/feed. Free posts appear in full and paid posts are truncated. See our Substack RSS feed guide for details.

Then choose a tool. Facts below are from each vendor's own page, read on October 24, 2026.

Tool	How it uses your Substack	LinkedIn	Medium	X	Entry price
IFTTT	"New post by user" trigger, polled hourly on Free, every 15 min on Starter, every 5 min on Pro (IFTTT)	Ready-made "Share Substack posts to LinkedIn" applet	No	Ready-made applet	Free plan
Buffer	Your RSS feed as a content feed; you pick items to share (Buffer)	Yes	No	Yes	Free: 3 channels, 10 scheduled posts each, up to 3 feeds (pricing)
Typefully	Schedules LinkedIn and X posts; also Substack Notes, "free to all users" (changelog)	Yes	No	Yes	See Typefully's site
Narrareach	"Connect any blog or RSS feed"; new posts are "cross-posted to Substack, Medium and LinkedIn" (pricing)	Posts, Articles and newsletters	Yes	From the $39/mo plan	$19.99/mo or $199/yr

Pick by how much control you want. IFTTT is fully automatic but posts the same template every time. Buffer brings each new post into your queue so you write a LinkedIn-specific intro first. Narrareach republishes full articles across platforms. Buffer is also an official Substack Notes partner, so you can announce each post as a Note from the same queue (Buffer Help). See Substack Notes.

How do I post to LinkedIn from my Substack RSS feed with code?

If you'd rather own the pipeline, LinkedIn's Share API is documented and free to use with your own developer app. Per LinkedIn's docs:

1. Create an app in the LinkedIn Developer Portal and add the Share on LinkedIn product, which grants the w_member_social scope.
2. Get a member access token through OAuth 2.0 with that scope, and your person URN.
3. POST https://api.linkedin.com/v2/ugcPosts with the header X-Restli-Protocol-Version: 2.0.0. An ARTICLE share carries your post URL in originalUrl.

LinkedIn lists a limit of 150 requests per member per day (LinkedIn), far more than a newsletter needs.

This Node 18+ script has no dependencies. It reads your feed, remembers which posts it has seen in seen.json, and shares only new ones. The first run just records existing posts, so you don't flood LinkedIn with your back catalogue. Without a token it prints the request bodies (a dry run). We tested the dry run against a live Substack feed on October 24, 2026.

// substack-to-linkedin.mjs: Node 18+, no dependencies.
//   FEED=https://yourpub.substack.com/feed node substack-to-linkedin.mjs   (dry run)
//   FEED=... LINKEDIN_TOKEN=... LINKEDIN_PERSON_URN=urn:li:person:XXXX node substack-to-linkedin.mjs
import fs from "node:fs";

const FEED = process.env.FEED;
const SEEN_FILE = process.env.SEEN_FILE || "seen.json";
const TOKEN = process.env.LINKEDIN_TOKEN;
const AUTHOR = process.env.LINKEDIN_PERSON_URN;

const text = (xml, tag) => {
  const m = xml.match(new RegExp(`<${tag}>(?:<!\\[CDATA\\[)?([\\s\\S]*?)(?:\\]\\]>)?</${tag}>`));
  return m ? m[1].trim() : "";
};

const xml = await (await fetch(FEED)).text();
const items = [...xml.matchAll(/<item>([\s\S]*?)<\/item>/g)].map(([, it]) => ({
  title: text(it, "title"),
  link: text(it, "link"),
  description: text(it, "description"),
}));

const seen = new Set(fs.existsSync(SEEN_FILE) ? JSON.parse(fs.readFileSync(SEEN_FILE, "utf8")) : []);
const firstRun = seen.size === 0;

for (const post of items.reverse()) {
  if (seen.has(post.link)) continue;
  seen.add(post.link);
  if (firstRun) continue; // first run only records what already exists

  const body = {
    author: AUTHOR || "urn:li:person:DRY_RUN",
    lifecycleState: "PUBLISHED",
    specificContent: {
      "com.linkedin.ugc.ShareContent": {
        shareCommentary: { text: `New post: ${post.title}\n\n${post.description}` },
        shareMediaCategory: "ARTICLE",
        media: [{ status: "READY", originalUrl: post.link, title: { text: post.title } }],
      },
    },
    visibility: { "com.linkedin.ugc.MemberNetworkVisibility": "PUBLIC" },
  };

  if (!TOKEN) {
    console.log(JSON.stringify(body, null, 2));
    continue;
  }
  const res = await fetch("https://api.linkedin.com/v2/ugcPosts", {
    method: "POST",
    headers: {
      Authorization: `Bearer ${TOKEN}`,
      "Content-Type": "application/json",
      "X-Restli-Protocol-Version": "2.0.0",
    },
    body: JSON.stringify(body),
  });
  console.log(post.link, res.status, res.headers.get("x-restli-id") || (await res.text()));
}

fs.writeFileSync(SEEN_FILE, JSON.stringify([...seen], null, 2));
console.log(firstRun ? `Recorded ${seen.size} existing posts. New posts will be shared from the next run.` : "Done.");

Run it every hour from cron or a scheduled GitHub Action, and commit seen.json back so state survives between runs. Member tokens expire, so plan to refresh yours. If you prefer a visual workflow, the same feed works as a trigger in n8n, and the identical pattern posts to a team channel in Substack to Slack.

How do I cross-post to Medium without hurting SEO?

Use Medium's import tool rather than pasting. Medium says it "will automatically backdate the post to the original date, as well as add a canonical link" to the original (Medium Help), which tells search engines your Substack post is the source. Publish on Substack first, wait for Google to index it, then import the URL. Our Substack vs Medium comparison covers when using both is worth it.

Does cross-posting create duplicate content?

It depends on what you post.

• A summary and a link (the LinkedIn and X default above) isn't duplicate content. It sends readers, and links, to your Substack.
• The full text on another site is syndication. Google calls rel=canonical "a signal which helps us with canonicalization, as a hint", and says that if you don't want syndicated versions in Search, they should "include a noindex robots meta tag" (Google Search Central, June 2023). Medium's import adds the canonical for you. On platforms where you can't set either, prefer an excerpt plus a link.

Our rule of thumb: give each network a native intro of three to five sentences in its own style, link to the full post, and keep Substack (or your custom domain) as the one full copy.

Where does newsletterapi fit?

The scripts above poll your feed themselves. The newsletterapi content webhook does the polling for you and calls your URL with a signed post.published event when a new post appears in your public RSS feed. Your automation then fetches the clean post from the Posts API (GET /v1/publications/yourpub.substack.com/posts/{slug}?format=markdown) and writes the LinkedIn or Medium version. Posting to those networks stays your automation's job, under your own accounts. We never log in to Substack. For the full map of official Substack surfaces, see the Substack API guide.