--- title: "Feed discovery with rel=\"alternate\"" category: foundations status: recommended url: https://specification.website/spec/foundations/feed-discovery/ updated: "2026-05-29" sources: - title: "HTML Living Standard — Link types: alternate" url: "https://html.spec.whatwg.org/multipage/links.html#link-type-alternate" publisher: "WHATWG" - title: "MDN — rel=alternate" url: "https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes/rel/alternate" publisher: "MDN" - title: "RSS 2.0 Specification" url: "https://www.rssboard.org/rss-specification" publisher: "RSS Advisory Board" - title: "RFC 4287 — The Atom Syndication Format" url: "https://www.rfc-editor.org/rfc/rfc4287" publisher: "IETF" - title: "JSON Feed 1.1" url: "https://www.jsonfeed.org/version/1.1/" publisher: "JSON Feed" source_repo: https://github.com/jdevalk/specification.website licence: CC-BY-4.0 --- # Feed discovery with rel="alternate" > If your site publishes a feed — RSS, Atom, or JSON Feed — announce it in with . Feed readers, agents, and browsers discover it without guessing the URL. ## What it is `` in `` declares an alternative representation of the current page or site — most commonly a syndication feed, but also a translated version, a print stylesheet, or, increasingly, the page's Markdown source. Feed readers, browsers, and a growing number of AI agents look for these links to subscribe, switch language, or fetch a machine-friendly version. For feeds specifically: ```html ``` The browser, [feed readers](https://en.wikipedia.org/wiki/Comparison_of_feed_aggregators), and tools like the [W3C Feed Validation Service](https://validator.w3.org/feed/) pick these up automatically. The `title` attribute is what the user sees in the subscribe UI — make it specific. ## Why it matters - **Feed readers cannot subscribe to what they cannot find.** Without ``, the user has to know the URL. With it, every modern reader auto-discovers from the homepage or any article. - **Browsers and OS-level readers (Safari, NetNewsWire, Reeder) use the same discovery hook.** - **Search engines and aggregators** treat `rel="alternate"` as the canonical signal for syndication. - **`rel="alternate"` is a multi-purpose link relation.** Pair the same pattern with `hreflang` for translated URLs (see [hreflang](/spec/i18n/hreflang/)), with `type="text/markdown"` for [Markdown source endpoints](/spec/agent-readiness/markdown-source-endpoints/), and with `media` for print or mobile alternates. Using it consistently teaches every tool that reads your site what to look for. ## How to implement **Pick the right MIME type.** Browsers and readers branch on it. | Format | MIME type | |---|---| | RSS 2.0 | `application/rss+xml` | | Atom 1.0 | `application/atom+xml` | | JSON Feed | `application/feed+json` | | Markdown source | `text/markdown` | **Include `title`** for every alternate. A reader's subscribe dialog shows the title verbatim. "RSS Feed" tells the user nothing; "Example — Engineering blog" does. **Put the most-preferred feed first.** Some readers offer the first alternate by default if there are several. **Use absolute URLs in the feed itself**, even if the `href` here is relative — see [machine-readable formats](/spec/agent-readiness/machine-readable-formats/). **Site-wide vs page-specific.** A blog index links to the main feed. An individual category page can additionally link to that category's feed. An individual post does not need its own feed. **Don't forget HTTP discovery.** Some readers also honour `Link` headers: ```http Link: ; rel="alternate"; type="application/rss+xml"; title="Example — Posts" ``` Useful for non-HTML responses (e.g. an API root) where there is no ``. ## Common mistakes - Using `type="text/xml"` or `application/xml` for an RSS feed. Some readers ignore it. - Linking to a feed that 404s, redirects, or fails validation. Run `https://validator.w3.org/feed/` on every feed URL before shipping. - Pointing all `` entries at the same URL "to be safe". Each entry must describe a distinct representation. - Omitting `title` and letting the reader guess. - Putting `rel="alternate"` on an `` link in the body. It only carries discovery semantics inside ``. ## Verification - `curl -s https://example.com/ | grep -i 'rel="alternate"'` returns each declared alternate. - Paste the homepage URL into a feed reader's "Add subscription" dialog — it should resolve to the correct feed without you typing the feed URL. - The W3C [feed validator](https://validator.w3.org/feed/) returns no errors on the linked feed. - View source on a per-language page and confirm `rel="alternate" hreflang="…"` siblings sit alongside any feed alternates without conflicting.