--- title: "SEO Integration for Multilingual WordPress - PerfLocale" description: "Hreflang, sitemap alternates, JSON-LD schema enrichment, Content-Language headers, Speculation Rules prerender, and View Transitions for multilingual WordPress." canonical: "https://perflocale.com/features/seo/" source: "https://perflocale.com/features/seo/" format: "markdown" --- # SEO Multilingual SEO handled automatically so search engines index the right language for every visitor. ``` ``` One hreflang cluster — auto-emitted in on every translated page ## Automatic Hreflang Tags PerfLocale tells search engines about every translated version of each page. Choose page source, HTTP headers, or both for maximum coverage. ## Sitemap Integration The built-in WordPress sitemap is extended to include links to every translation. Search engines discover all your translated content automatically. SEO tag generation per request requests over time → **Build** & cache **Cache hit** 1. 1 First request builds the cluster Hreflang tags, JSON-LD entities, Content-Language headers — computed once and stored in the WP object cache. 2. 2 Every later request hits the cache No DB lookups, no recomputation — tags are pulled directly from Redis / Memcached / transients. 3. 3 Translation edits auto-invalidate PerfLocale watches your translations — the next page load rebuilds fresh tags. **No stale tags ever served.** ## Cached for Performance SEO tags (hreflang, sitemap alternates, Content-Language headers, schema enrichment) are built once per page context and cached for 12 hours, so subsequent requests skip the rebuild and just emit the cached HTML. Cache clears itself when translations change. Auto-detected Yoast SEO active — its addon wires into Yoast’s sitemap and schema - Yoast SEO Addon matched · filtering `wpseo_schema_graph` Active - Rank Math Handler available Dormant - SEOPress Handler available Dormant - AIOSEO Handler available Dormant - Slim SEO Handler available Dormant - The SEO Framework Handler available Dormant Pay only for what runs Dormant addons don’t load any code — only the matched one runs. ## Smart Plugin Detection If you use Yoast, Rank Math, SEOPress, AIOSEO, Slim SEO, or The SEO Framework, the matching PerfLocale addon activates on its own and wires into that plugin’s sitemap and JSON-LD output — translated entries appear in its sitemap, and its schema graph gets the right `inLanguage`. Hreflang itself stays a single source: none of the six emit head or header hreflang without a multilingual integration, so PerfLocale’s tags are the only ones on the page. The other five addons stay dormant and load no code. ``` // Auto-augmented when the enrichment setting is on { "@type": "WebPage", "@id": "https://acme-bakery.com/about/#webpage", "inLanguage": "en-US", "workTranslation": [ { "@type": "WebPage", "@id": "https://acme-bakery.com/de/ueber-uns/#webpage", "inLanguage": "de" }, { "@type": "WebPage", "@id": "https://acme-bakery.com/en-gb/about/#webpage", "inLanguage": "en-GB" } ] } ``` inLanguage per entity · workTranslation siblings cross-linked ## JSON-LD Schema Enrichment PerfLocale augments the structured-data output of Yoast, AIOSEO, Rank Math, SEOPress, Slim SEO, and The SEO Framework. Every `WebPage`/`Article`/`Product` entity in the schema graph gets the correct `inLanguage` value, and translated siblings are cross-linked via `workTranslation`. On by default; zero runtime cost. [Read the JSON-LD schema enrichment docs](https://perflocale.com/docs/seo-schema/). ## Modern SEO & UX Four features that address gaps specifically affecting multilingual sites - each solves a problem that a generic SEO plugin can't, because only a translation-aware plugin knows the sibling graph and the fallback state. ``` HTTP/1.1 200 OK Date: Tue, 30 Apr 2026 09:00:00 GMT Server: nginx Content-Type: text/html; charset=utf-8 Cache-Control: public, max-age=3600 Vary: Accept-Encoding, Accept-Language Content-Language: de-DE+ PerfLocale ``` W3C-standard signal on top of `` · Google, Yandex, and most CDN/proxy layers use it as a ranking hint ## Content-Language HTTP Header The W3C-standard `Content-Language` response header tells search engines and proxies the page's language in BCP-47 format (`de-DE`, `fr-CA`, etc.) on top of ``. Google, Yandex, and most CDN/proxy layers use it as a ranking signal. No downside - on by default. Fallback wrapper PerfLocale emits ```

Welcome to our bakery — we bake…

``` Without the guard acme-bakery.com › de › about Über uns — Acme Bakery Welcome to our bakery — we bake artisan sourdough every morning, source flour from a Devon mill… English snippet under a German URL — visitor confused, bounces. With PerfLocale guard acme-bakery.com › de › about Über uns — Acme Bakery — snippet omitted (`data-nosnippet`) — Page still indexed · no language mismatch in the SERP. ## Fallback-Content Snippet Guard When a translation is missing and you show the default language as fallback, Google indexes the English text under the `/de/` URL - and happily serves English snippets in German SERPs, confusing visitors. PerfLocale wraps the fallback block with `data-nosnippet` so Google still indexes the page but omits the mismatched text from snippets. On by default; only triggers when fallback is actually active. **We’re not aware of another multilingual plugin that does this.** Click → page visible Without prerender TLS server DOM paint Full navigation With PerfLocale already prerendered Already loaded 1. 1 Hover or focus Visitor lands on the 🇩🇪`Deutsch` link in the switcher. 2. 2 Background prerender Chromium fetches and renders `/de/uber-uns/` off-screen via Speculation Rules. 3. 3 Click → instant swap Page is already there — visible the moment they click. Moderate eagerness triggers on hover / focus only — **no bandwidth cost** for visitors who never switch. ## Instant Language Switching Off by default and marked experimental in the settings. When a visitor hovers or focuses a language-switcher link, Chromium prerenders the target translation in the background. Language switch becomes effectively instant - the page is already loaded by the time they click. On WordPress 6.8+, PerfLocale integrates with Core's native [Speculation Rules API](https://make.wordpress.org/core/2025/03/06/speculative-loading-in-6-8/) via the `wp_load_speculation_rules` action - our rule lands inside Core's single speculation-rules script, automatically inherits any `/cart/*`/`/checkout/*` exclusions other plugins register, and respects the global opt-out filter. On older WP it falls back to emitting a standalone script with the same behavior. Moderate eagerness triggers only on hover/focus, so there's no bandwidth cost for visitors who never switch. EN DE 240 ms crossfade View Transitions API Standard navigation — **white flash**, jarring View Transitions — **smooth crossfade**, no flash Accessibility Respects `prefers-reduced-motion` — users who opt out get instant navigation. WCAG 2.1 SC 2.3.3 compliant. ## Smooth Switch Animation Using the [View Transitions API](https://developer.mozilla.org/en-US/docs/Web/API/View_Transition_API) (Chrome 126+, Safari 18.2+), switching between languages crossfades smoothly between the old and new page - no white flash. Off by default and marked experimental in the settings: the opt-in is page-wide, so once enabled every same-site navigation crossfades, and a theme that runs its own on-navigation animations can clash with it - test before turning it on. Browsers without support just navigate normally; zero breakage. Progressive enhancement you can turn on in seconds. **Accessibility:** the default CSS respects `prefers-reduced-motion` - users with the OS-level reduced-motion preference see instant navigation without the 240ms crossfade. WCAG 2.1 SC 2.3.3 compliant out of the box. See the [Accessibility page](https://perflocale.com/features/accessibility/#reduced-motion) for details. [← Back to Features](https://perflocale.com/features/)