Official statement
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- 60:22 Le Server-Side Rendering est-il vraiment indispensable pour le SEO en 2025 ?
- 121:54 Googlebot est-il vraiment devenu infaillible face à JavaScript ?
- 152:49 Pourquoi le passage à Evergreen Chrome transforme-t-il le rendu des pages par Google ?
- 183:08 Google rend-il vraiment TOUTES vos pages JavaScript ?
- 196:12 Pourquoi Google ne clique-t-il jamais sur vos boutons Load More et comment l'éviter ?
- 226:28 Faut-il vraiment masquer le contenu cumulatif des paginations infinies à Google ?
- 251:03 Peut-on vraiment servir une navigation différente à Google sans risquer une pénalité pour cloaking ?
- 271:04 Googlebot clique-t-il vraiment sur les boutons et liens JavaScript de votre site ?
- 303:17 Faut-il créer une page par jour pour un événement multi-jours ou canoniser vers une page unique ?
- 402:37 Le JavaScript est-il vraiment compatible avec le SEO moderne ?
Google claims that large JSON hydration strings at the bottom of the page do not pose any indexing issues. Creating a specific code path for bots by removing this JSON adds unnecessary technical complexity and risk of fragility. In practical terms: let your JavaScript application generate the same markup for all clients, including bots.
What you need to understand
What is JSON hydration and why do some sites hide it from bots?*
Hydration is the process by which a JavaScript framework (React, Vue, Next.js) transforms static HTML into an interactive client-side application. To work, the framework often injects a large JSON object at the bottom of the page, containing the initial state of the application — sometimes several hundred kilobytes.<\/p>
Some developers fear that this JSON burdens the DOM, dilutes the semantic density perceived by Google, or constitutes duplicate content if the JSON repeats data already present in the HTML. The result: they create server-side logic that detects Googlebot and disables JSON injection for this client only.<\/p>
Why does Google advise against this practice?*
Martin Splitt cuts to the chase: this JSON is not a problem for the engine. Google parses the final rendered HTML, and the hydration JSON — often placed in a On the other hand, creating a specific code branch for bots introduces fragility: there is a risk of divergence between what the user sees and what Google sees (inadvertent cloaking), deployment bugs if User-Agent detection fails, and increased maintenance. All this for no gain.<\/p> Splitt explicitly talks about hydration JSON — the one generated by modern frameworks to rehydrate the interface. He does not speak about other uses of JSON: structured data (JSON-LD), analytics tracking data, or third-party configurations.<\/p> The statement does not cover cases where the JSON contains raw editorial content (complete articles, product descriptions) with no visible HTML equivalent. In this latter case, the question of indexing arises differently — but that is not the subject here.<\/p><script type="application/json"><\/code> — is not interpreted as indexable textual content. It dilutes nothing and does not create penalizing duplication.<\/p>Does this statement apply to all types of bottom JSON?*
<script><\/code> is not considered textual content.<\/li>
SEO Expert opinion
Is this statement consistent with field observations?*
Yes, and it confirms what empirical tests have shown for several years. Sites using SSR (Server-Side Rendering) with hydration — Next.js, Nuxt, SvelteKit — index correctly even with significant JSON payloads at the bottom of the page. Google has made enough progress in JavaScript rendering to ignore what pertains to technical plumbing.<\/p>
What really poses a problem is critical asynchronous rendering: content loaded after client-side JS execution, without an initial HTML equivalent. The hydration JSON, on the other hand, assumes the HTML is already present — therefore indexable.<\/p>
What nuances should be added?*
Splitt's statement relies on an implicit assumption: your initial HTML already contains complete semantic content. If your framework generates an empty shell on the server side and all content is displayed via JavaScript after hydration, you are out of scope — and in SEO trouble. [To verify]: Google has never specified a size threshold beyond which a hydration JSON would become problematic. It is assumed there is none, but public tests on payloads of several megabytes remain rare.<\/p>
Another point: if your JSON contains readable structured data (prices, reviews, descriptions) but the equivalent HTML is absent or hidden, Google could theoretically ignore them — but this is no longer a hydration problem; it is an architectural issue.<\/p>
In what cases does this rule not apply?*
If you are doing deliberate cloaking — serving different HTML to Google to hide sensitive content or manipulate ranking — the presence or absence of JSON becomes the least of your concerns. Google penalizes behavior, not JSON.<\/p>
If your site uses pure CSR (Client-Side Rendering) without server pre-rendering, you probably don’t have hydration JSON in the strict sense — you have a JS bundle that generates everything on the fly. Here, the problem is not the JSON; it's the absence of indexable initial HTML.<\/p>
Practical impact and recommendations
What should you do with hydration JSON in practice?*
Do nothing. Let your framework inject its hydration JSON normally for all clients without distinction. If you are using Next.js, Nuxt, or an equivalent in SSR/SSG, the automatically generated JSON (often in Make sure that the server-side rendered HTML already contains the complete textual content — titles, paragraphs, product data. The JSON should only serve to rehydrate the interactive interface, not to replace missing content.<\/p> Do not create User-Agent detection logic to hide the JSON from bots. This introduces a divergence between user experience and bot experience, which can be interpreted as cloaking — even inadvertently. Google values source code consistency.<\/p> Do not confuse payload optimization with JSON removal. If your hydration JSON weighs 500 KB, the problem is not that it exists; it's that it's too big. Optimize the size of data on the server side (pagination, lazy loading of non-critical states), but do not remove it for Googlebot.<\/p> Use Google Search Console and the URL inspection tool. Compare the raw HTML (View Source) with the rendered HTML ("Rendered HTML" tab). If the textual content is identical in both cases, your hydration works correctly — the JSON is transparent to Google.<\/p> Also test the rendering speed with Lighthouse. A very large JSON can slow down Time to Interactive (TTI) and Total Blocking Time (TBT), which indirectly degrades SEO via Core Web Vitals. If your scores drop, reduce the size of the JSON but do not remove it.<\/p>__NEXT_DATA__<\/code>) requires no intervention.<\/p>What mistakes to avoid?*
How to check if my implementation is compliant?*
❓ Frequently Asked Questions
Le JSON d'hydratation est-il indexé par Google comme du contenu textuel ?
Dois-je supprimer le JSON d'hydratation pour Googlebot ?
Un JSON d'hydratation très volumineux peut-il nuire au SEO ?
Cette règle s'applique-t-elle aux sites en CSR pur (Client-Side Rendering) ?
Comment vérifier que mon JSON d'hydratation ne cause pas de problème SEO ?
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