Each row must match code=URL
Rows that do not match the expected pattern stop generation with an error rather than being silently skipped.
Free browser tool
Generate hreflang and x-default tags from language-code and URL pairs.
Generate alternate-language link tags from language-code and absolute-URL pairs, with an optional x-default URL.
language=https://... pair per line.<link rel="alternate"> tags.ja=https://example.com/ and en=https://example.com/en/ produce separate hreflang link elements; an x-default line is added when supplied.The generator checks a simple language-code pattern, not full BCP 47 correctness or reciprocal hreflang implementation across live pages.
Rows that do not match the expected pattern stop generation with an error rather than being silently skipped.
The input pattern expects a full http:// or https:// destination, not a relative path.
When provided, x-default can point to a locale selector or fallback page for users who do not match a listed language/region.
Search engines generally expect alternate pages to reference one another consistently. Generated tags are only one part of that implementation.