Knowledge base v2.13.0 · Community edition · data through 2 October 2026
Thing · Directive
Annotations that tell Google which language or regional versions of a page exist, so it can show the right one to each user.
Glossary · hreflang
Annotations that tell Google which pages are language or regional versions of each other, so it can show the right one. They do not set a page's language.
Documented in
Google's canonical guide says that for canonicalization Google prefers URLs that are part of hreflang clusters: if German pages for Germany and Switzerland point to each other with hreflang but not to the Austrian page, the German and Swiss pages are preferred as canonicals.
Google Search Central · Day 2 · Handling web duplication
Google's guide to specifying canonical URLs says that on pages using hreflang, the canonical should be a page in the same language, or the best possible substitute language if no canonical page exists in the same language.
Google Search Central · Day 2 · Lightning session E: Managing Duplicates and Site Moves
Google's documentation says Googlebot mostly crawls from US IP addresses and sends no Accept-Language header, so pages that change content or redirect by the visitor's perceived country or language may not have every version crawled, indexed or ranked; it recommends separate URLs annotated with hreflang.
Google Search Central · Day 2 · Focusing on Internationalisation and Localisation
Google's hreflang guide says language-specific subdomains such as en, en-gb or de in a URL are not used to determine a page's target audience; site owners must map the audience explicitly, for example with hreflang.
Google Search Central · Day 2 · Focusing on Internationalisation and Localisation
Google's hreflang guide says its three methods (link elements in the HTML head, an HTTP Link header, which suits non-HTML files such as PDFs, and an XML sitemap) are equivalent; using several at once is allowed but brings no benefit in Search and is harder to manage.
Google Search Central · Day 2 · Focusing on Internationalisation and Localisation
Google's hreflang guide says a site that finds it hard to keep every language pair bidirectional may omit some languages on some pages, because Google still processes the pairs that point to each other; new language versions should at least link both ways with the original or dominant language.
Google Search Central · Day 2 · Focusing on Internationalisation and Localisation
Google's hreflang guide says alternate URLs must be fully qualified, including the protocol (https://example.com/foo, not //example.com/foo or /foo), and need not be on the same domain.
Google Search Central · Day 2 · Focusing on Internationalisation and Localisation
Google's hreflang guide says pages that translate only the template (navigation, footer) around main content in one language still count as duplicates, because localized versions are duplicates only if the main content stays untranslated; it recommends hreflang for such pages.
Google Search Central · Day 2 · Focusing on Internationalisation and Localisation
Google's hreflang guide says the ISO 639-1 language code can be followed by a script in ISO 15924 format, such as zh-Hant or zh-Hans, and by an optional ISO 3166-1 Alpha-2 region code, as in zh-Hans-US.
Google Search Central · Day 2 · Focusing on Internationalisation and Localisation
Google's documentation recommends hreflang annotations even when a site's versions differ only by small regional variations within one language, for example English-language content targeted to the US, GB and Ireland.
Google Search Central · Day 2 · Lightning session G: Internationalisation
Google's documentation lists the signals it uses to decide which locale a page targets: ccTLDs, hreflang statements, server location, and other signals such as local addresses and phone numbers, local language and currency, links from other local sites and Business Profile signals.
Google Search Central · Day 2 · Lightning session G: Internationalisation
Slide and stage claims that name it, the ones Google’s documentation does not cover first.
A community speaker cited a Semrush study that found at least one hreflang error on 75% of multilingual websites; the study, reported in February 2017, audited 20,000 sites with several language versions (the speaker recalled it as about five years old).
Alizée Baudez · Day 2 · Lightning session G: Internationalisation
The speaker said that knowing a page's other-language versions from hreflang is useful in ranking.
Google's closing suggestions on duplication: use redirects for site migrations, use HTTP result codes, don't block agents, check your rel=canonical links, use hreflang links to help Google localize, report weird canonicals in the forums, make secure pages that work, and keep canonical signals clear.
Each page in an hreflang set must also list its own URL, and a missing self-reference is a common mistake Google sees.
Any one hreflang method is fine, but a site should use only one: Google often sees sites using two or three methods at the same time, with annotations that conflict.
hreflang language codes must be ISO 639-1 codes: Google's list of common mistakes marked se, dk and cz (the country codes of Sweden, Denmark and Czechia) as wrong and sv, da and cs (Swedish, Danish, Czech) as right.
Site owners do not need to memorise hreflang language and region codes, but should double-check every code when implementing hreflang.
Czech is a frequent hreflang error: CZ is the country code and ccTLD of Czechia, but the language code for Czech is cs.
hreflang region codes must be ISO 3166-1 Alpha-2 country codes; frequent mistakes are UK instead of GB for the United Kingdom, SW instead of CH for Switzerland and GE instead of DE for Germany.
Google also flagged LA used as a region code for Los Angeles (a city, not a country) and SA used for South Africa as wrong hreflang region codes.
Google said incorrect hreflang language or region codes are a mistake it finds very often, with the same wrong codes coming up again and again, especially in Europe, because site owners assume the codes are easy.
A community speaker stressed that an hreflang annotation for a country (her example was German for Austria, de-AT) does not by itself make a site established or trusted in that country; local authority has to be worked for.
Alizée Baudez · Day 2 · Lightning session G: Internationalisation
Google extracts hreflang annotations, through which site owners specify the language variants of their content, to know whether a page has an equivalent with similar content in another language.
Alternate names also serve localization: if Google knows that country versions such as you.de and you.at are equivalent, it can pick the right version to show using hreflang.
When localized pages are clustered, Google tries to use hreflang alternates; the speaker's short version of the advice was to use hreflang, which he called really helpful for same-language, different-country content.
Language versions of a page should be connected with hreflang annotations instead of canonical links.
Tobias Schwarz · Day 2 · Lightning session E: Managing Duplicates and Site Moves
Google's hreflang example lists every language version in the page's HTML head as a link element with rel=alternate, the version's full URL and its hreflang code (en, en-gb, es), including the page's own URL.
Missing return links are a common hreflang mistake: if page X names page Y as a language version, page Y must link back to page X.
When the HTML head is not suitable for a page, hreflang can be given by other methods instead, such as listing the language versions in a sitemap.
Google ignores hreflang annotations that point only one way, where page A names page B as a language version but page B does not name page A back.
Google requires hreflang return links because an alternate URL is a full URL that can be on any domain, so without them any site could declare itself a language version of someone else's website.
EU is not a valid hreflang region code: sites use it hoping to target the European Union, but hreflang targeting works only by country.
A region code cannot be used on its own in hreflang: en and en-GB are valid values, but GB alone is not, because the value must name a language.
Google does not use hreflang to determine a page's language when indexing the page.
In a community speaker's audit case, a premium multifunctional-furniture maker about to be acquired had multilingual sites with clean translations by native speakers and hreflang tags that were in fairly good shape.
Alizée Baudez · Day 2 · Lightning session G: Internationalisation
A community speaker framed international SEO around three signals to settle before working on hreflang: language (what people can read), region (who the content is for) and authority (why local people should trust the site).
Alizée Baudez · Day 2 · Lightning session G: Internationalisation
A community speaker said the SEO industry has treated hreflang as the hard part of international SEO; hreflang is complicated, but the real hard part is the homework of understanding consumers in each market.
Alizée Baudez · Day 2 · Lightning session G: Internationalisation
Put rel=canonical and hreflang link elements in the head of the HTML the server sends, not only in JavaScript-rendered HTML, so Google can read them during HTML parsing without depending on rendering.
Ibrahim Anjro · Day 2 · How is HTML interpreted
For German-language sites serving Germany, Austria and Switzerland, add hreflang with region codes (de-DE, de-AT, de-CH) and make the country pages differ in more than boilerplate (prices, shipping, legal details), or expect Google to cluster them and show one.
Ibrahim Anjro · Day 2 · Handling web duplication
Before a migration or template change, align every canonical signal for the preferred URL (redirects, rel=canonical, internal links, sitemap entries, hreflang and working HTTPS); Google says it follows the site owner only when the signals agree.
Ibrahim Anjro · Day 2 · Handling web duplication
Check that every canonical group contains a single document language: a group spanning languages means canonicals are joining versions that hreflang should connect, and each language version should keep its own self-referencing canonical.
Ibrahim Anjro · Day 2 · Lightning session E: Managing Duplicates and Site Moves
Audit hreflang per cluster rather than per page: check that every page lists itself and all its alternates, that every alternate links back, and that only one method (HTML head, HTTP header or sitemap) supplies the annotations.
Ibrahim Anjro · Day 2 · Focusing on Internationalisation and Localisation
Validate hreflang values against the ISO 639-1 and ISO 3166-1 Alpha-2 lists in a crawler rule or build check rather than by eye: reserved codes such as UK and EU are simply ignored, but some plausible mistakes are valid codes for something else (se is Northern Sami, GE Georgia, LA Laos, SA Saudi Arabia) and silently point the annotation at the wrong audience.
Ibrahim Anjro · Day 2 · Focusing on Internationalisation and Localisation
When translations and hreflang are clean but one country version converts far worse, compare that market's product range, photography and delivery or installation constraints with local competitors before changing anything technical.
Ibrahim Anjro · Day 2 · Lightning session G: Internationalisation
Treat hreflang as a way to show the right language version, not as a market-entry signal: before launching a country version, make sure local publications, partners or directories already mention the brand, and localise pricing and payment options.
Ibrahim Anjro · Day 2 · Lightning session G: Internationalisation
A site serving a smaller country in a big language, such as British English or Swiss German, should make that country unmistakable (country-code domain or region-specific hreflang, local address, prices and currency) so its pages can benefit from index selection's country balancing instead of competing with the much larger US or German content pool.
Ibrahim Anjro · Day 2 · Calculating (some) signals
Sites with several language versions should not leave brand searches to chance: annotate the versions with hreflang and offer a visible language switcher, because Google may have only the user's location and browser settings to choose a version.
Ibrahim Anjro · Day 3 · Making sense of users' queries
Make each page's language and target country unambiguous (one main language per page, hreflang between versions, local prices, addresses and shipping details), because Google applies language and country already at retrieval, before ranking.
Ibrahim Anjro · Day 3 · Making sense of users' queries
Kit items about hreflang: their own words name it, or several of the claims they rest on do.
Make hreflang complete: a self-reference, return links and fully qualified URLs
Rests on 12 claims, 9 of them naming hreflang; its own words name hreflang
Rests on 10 claims, 9 of them naming hreflang; its own words name hreflang
Differentiate same-language country versions beyond boilerplate and mark them with region codes
Rests on 6 claims, 5 of them naming hreflang; its own words name hreflang
Do not canonicalise one language version to another; connect them with hreflang
Rests on 4 claims, 3 of them naming hreflang; its own words name hreflang
Supply hreflang through one method only: HTML head, HTTP Link header or sitemap
Rests on 3 claims, 3 of them naming hreflang; its own words name hreflang
Make each page's language unambiguous by translating the template with the main content
Rests on 12 claims, 3 of them naming hreflang; its own words name hreflang
Make all canonical signals agree: redirects, rel=canonical, internal links, sitemaps and hreflang
Rests on 6 claims, 1 of them naming hreflang; its own words name hreflang
Do not redirect visitors automatically by IP address or browser language
Rests on 2 claims, 1 of them naming hreflang
Also inglossary terms hreflang, hreflang return link
Things named in the same claim, with the number of claims they share.