Why is Google pushing JSON-LD when Microdata and RDFa work too?

Official statement

The JSON-LD format is preferred for structured data because it is easy to implement and does not require rendering processing to be understandable by search engines.

61:58

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Extracted from a Google Search Central video

⏱ 59:34 💬 EN 📅 15/11/2019 ✂ 9 statements

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✂ Other statements from this video 8 ▾

2:07 Faut-il encore se soucier du crawler desktop en indexation mobile-first ?
3:11 Faut-il vraiment utiliser l'outil de gestion des paramètres d'URL pour optimiser le crawl ?
3:42 Comment gérer les URLs canoniques entre mobile et desktop sans tout casser ?
8:26 Les rich results dépendent-ils vraiment de la qualité globale du site ?
30:14 Pourquoi l'API d'indexation Google est-elle inaccessible pour 99% des sites web ?
32:53 Les données structurées Product sont-elles vraiment adaptées aux entités complexes à variantes multiples ?
46:33 Les grandes images boostent-elles vraiment votre visibilité dans Google Discover ?
57:20 Faut-il vraiment ignorer les scores de performance pour le SEO ?

What you need to understand

Does JSON-LD really eliminate the need for JavaScript rendering on Google's end?

Yes, and that's the nuance. JSON-LD is injected directly into the HTML source, allowing Googlebot to read it right from the first crawl pass, without waiting for JavaScript execution. Microdata and RDFa, on the other hand, are integrated into the visible DOM — if that DOM is generated by JS (React, Vue, Next.js...), Google first needs to render the page.

Rendering takes time and affects crawl budget. On a site with thousands of pages, this latency adds up. JSON-LD allows you to bypass this step: the schema is available immediately, even if the rest of the page takes 2 seconds to display on the client side.

Are Microdata and RDFa obsolete because of this?

No. Google continues to officially support them, and some CMSs (notably WordPress) still generate Microdata by default through their plugins. The issue is not compatibility, but the speed of interpretation and maintenance simplicity.

With Microdata, you have to modify the HTML of your templates—every design change can break your tags. JSON-LD exists in a self-contained <script type="application/ld+json"> block, which can be injected via GTM, a plugin, or a PHP snippet without ever modifying the visible structure of the page.

What does "easy to implement" mean from Google's perspective?

Google is speaking here for developers, not for SEOs. "Easy" means: no HTML overhaul, no CSS classes to add everywhere, and no risk of design conflicts. You place your JSON in the <head>, validate it via Search Console, and you’re done.

However, for an e-commerce site with 50,000 product listings, generating clean and up-to-date JSON-LD remains a serious technical challenge. You need to map back-office data (price, stock, reviews, images) to Schema.org properties, manage variants, currencies, and availability. The complexity is just shifted, not eliminated.

JSON-LD is crawled immediately, without waiting for JS rendering
Microdata and RDFa remain valid but are harder to maintain
"Easy" does not mean "automatic"—you still need to code the business logic behind it
Google does not claim that JSON-LD boosts ranking—just that it simplifies processing on the search engine's side

SEO Expert opinion

Does this stated preference hide a real ranking advantage?

Let’s be honest: no public data proves that JSON-LD ranks better than Microdata. Google has been stating for years that format does not directly influence ranking. What matters is the quality and consistency of structured data, not their syntax.

However—and this is where it gets tricky—if your Microdata relies on erratic JS rendering and Googlebot only sees it one out of three times, you are mechanically depriving yourself of rich snippets, carousels, and enhanced featured snippets. So yes, indirectly, JSON-LD can impact SERP visibility. [To be verified] on your own data: compare the display rate of rich results between JSON-LD pages and Microdata pages via Search Console.

What situations pose a problem for JSON-LD?

First case: client-side generated content only. If your price is displayed via an API called after loading, your static JSON-LD in the <head> will contain outdated data. You then have to regenerate the JSON dynamically, which cancels out some of the promised simplicity.

Second case: unintentional duplication. I’ve seen sites injecting JSON-LD via GTM AND via a WordPress plugin, resulting in two identical Schema blocks, sometimes contradictory. Google tolerates these inconsistencies poorly—you end up with warnings in Search Console and, at times, no rich snippet displayed.

Should you migrate from Microdata to JSON-LD today?

If your Microdata works, is validated in Search Console, and generates stable rich results, don’t change a thing. Migration means development time, risks of regression, and zero measurable gains in terms of ranking.

On the other hand, if you are launching a new site, if you are redesigning your front end in React/Next, or if your rich snippets randomly disappear, go straight to JSON-LD. It’s the most robust format against technical evolutions (SSR, client hydration, edge rendering...).

Warning: some CMSs automatically inject Microdata (Shopify, PrestaShop...). If you add JSON-LD on top of that without disabling the native Microdata, you risk conflicts. Always check the final HTML source.

Practical impact and recommendations

What steps should you take to properly implement JSON-LD?

First step: audit what already exists. Scrape your site (Screaming Frog, OnCrawl) and extract all structured blocks—Microdata, RDFa, JSON-LD. You will often find surprises: orphaned schemas, poorly populated properties, obsolete types.

Next, define the priority Schema.org types for your sector. E-commerce? Product, Offer, Review, BreadcrumbList. Media? Article, NewsArticle, VideoObject. Local? LocalBusiness, OpeningHoursSpecification. There’s no need to implement everything at once—better to do 3 types well than 15 halfway.

How can you check that JSON-LD is being interpreted correctly by Google?

The rich results test from Google is your first filter. Paste the URL or HTML code, and check for any critical errors. However, this test does not indicate whether Google will display the rich snippet—only if it can read it.

Second check: Search Console, Enhancements section. Look at the reports for Product, Recipe, FAQ, etc. If valid pages do not appear in SERPs with their rich snippets after 2-3 weeks, it means Google chose not to display them—often due to content deemed irrelevant or too much competition.

What errors should you absolutely avoid?

Never inject data that is invisible to the user. Google penalizes deceptive schema markup: displaying 5 stars in JSON when the page shows no reviews, artificially inflating the number of reviews, inventing a stricken price. If it’s in the schema, it must be visible on the page.

Another trap: missing mandatory properties. For a Product, Google requires name, image, and either offers or review. If you forget offers.price or offers.availability, your rich snippet will never be displayed. Educate yourself on schema.org, not just on half-accurate Medium tutorials.

Audit existing content: identify all schema formats currently present (Microdata, RDFa, JSON-LD)
Define the priority Schema.org types according to your sector (Product, Article, LocalBusiness...)
Dynamically generate JSON-LD if data changes on the client side (price, stock, reviews)
Validate with the Rich Results Test AND check actual display in SERP after indexing
Monitor Search Console Enhancements reports to detect errors and warnings
Never add structured data that is missing from the visible content of the page

JSON-LD simplifies crawling and maintenance, but its large-scale deployment (thousands of pages, dynamic data, custom CMS) remains a non-trivial technical project. If you want to fully leverage rich results without risking costly visibility errors, hiring a specialized SEO agency can save you months of trials and ensure an implementation that complies with Google’s standards.

❓ Frequently Asked Questions

JSON-LD améliore-t-il directement le classement organique ?

Non, Google affirme que le format des données structurées (JSON-LD, Microdata, RDFa) n'est pas un facteur de ranking direct. En revanche, JSON-LD facilite l'affichage de rich snippets, ce qui peut améliorer le CTR et indirectement impacter la visibilité.

Peut-on mélanger JSON-LD et Microdata sur une même page ?

Techniquement oui, Google tolère les deux formats simultanément. Mais attention aux conflits : si les données se contredisent (prix différents, notes différentes), Google peut ignorer l'ensemble ou n'afficher aucun rich snippet.

Faut-il placer le JSON-LD dans le <head> ou dans le <body> ?

Les deux emplacements fonctionnent. Google recommande le <head> pour simplifier la maintenance et garantir que le schema soit crawlé même si le <body> met du temps à charger ou dépend de JavaScript.

Est-ce que Google Tag Manager est une bonne solution pour injecter du JSON-LD ?

Oui, à condition que GTM s'exécute côté serveur (Server-Side GTM) ou que le rendu soit effectué avant le crawl. Si GTM injecte le JSON-LD uniquement côté client après le chargement, Googlebot peut le manquer lors du premier crawl.

Comment savoir si mes données structurées sont effectivement utilisées par Google ?

Vérifie les rapports "Améliorations" dans Search Console (Product, Recipe, FAQ, etc.). Si tes pages sont indexées mais n'apparaissent pas dans ces rapports, Google ne les exploite pas — souvent par manque de pertinence ou erreur de balisage.

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