link rel=alternate Feed Type Lookup
Builds link rel=alternate feed metadata for RSS or Atom with the standard media type and an escaped caller-supplied href. URL fetching and feed document validation are separate.
Description
Feed autodiscovery links identify an alternate RSS or Atom representation of a page.
Feed autodiscovery links identify an alternate RSS or Atom representation of a page. The feed format determines the media type advertised in the link element.1
The tool returns mediaType, element. The fields describe the supplied local pattern or effective state, or contain the formatted markup shown below.
When to use link rel=alternate Feed Type Lookup
Use this for the following task: Builds link rel=alternate feed metadata for RSS or Atom with the standard media type and an escaped caller-supplied href. URL fetching and feed document validation are separate. Provide the requested local fields extracted from the relevant element or attribute.
How to use link rel=alternate Feed Type Lookup and understand its results
- Prepare the parsed element names, attribute values or direct element-child lists requested below. Keep attribute presence separate from its value.
- Enter format, href according to the field table, then run the tool.
- Read mediaType, element. Check the effective state, recognized-token flags or generated markup against the rules below.
- Correct any reported local mismatch and check the resulting markup in its intended document and browser context.
| Input field | Meaning | Value type and bounds | Requirement |
|---|---|---|---|
| format | Format | string; choices "rss", "atom" | Required |
| href | Href | string; maximum text length 10000 | Required |
Choose rss or atom and supply a nonempty href without null, carriage return or newline. Select the media type and escape href for a double-quoted link attribute.
rss → application/rss+xml; atom → application/atom+xml The symbols and boundary conditions refer to the supplied fields and the implementation described above.
| Output field | Meaning | Value type |
|---|---|---|
| mediaType | Media Type | string |
| element | Element | string |
{
"input": {
"format": "atom",
"href": "/feed.xml?a=1&b=2"
},
"output": {
"mediaType": "application/atom+xml",
"element": "<link rel=\"alternate\" type=\"application/atom+xml\" href=\"/feed.xml?a=1&b=2\">"
}
}Limitations and assumptions
Relative href values are accepted, but URL syntax and feed content are not validated. No resource is fetched.
The tool does not fetch a page, run a browser or validate an entire HTML document. Malformed tool requests produce input errors; valid requests can still report unrecognized values or failed local checks.
Alternative or Complementary methods
Choose hreflang Alternate Language Pairs when you need its operation: Checks supplied hreflang/href pairs for nonempty values and repeated language labels ignoring ASCII case. It does not validate BCP 47 registry membership, URL syntax, reciprocal links or search-engine selection. Choose Canonical link rel Check for the complementary operation: Checks the canonical relation and a nonempty parsed href. Relative href values are accepted; this does not establish URL validity or canonical selection by search engines.
Background reference: HTML Standard: link rel=alternate Feed Type Lookup.
References
Similar or alternative tools
- hreflang Alternate Language Pairs
Checks supplied hreflang/href pairs for nonempty values and repeated language labels ignoring ASCII case. It does not validate BCP 47 registry membership, URL syntax, reciprocal links or search-engine selection.
- Canonical link rel Check
Checks the canonical relation and a nonempty parsed href. Relative href values are accepted; this does not establish URL validity or canonical selection by search engines.