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Official statement

In SEO terms, Google treats <strong> and <b> tags identically for ranking, scoring, and indexing. Therefore, there is no difference in SEO between these two tags.
0:31
🎥 Source video

Extracted from a Google Search Central video

⏱ 1:34 💬 EN 📅 21/10/2013 ✂ 2 statements
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Other statements from this video 1
  1. 0:34 Les balises <em> et <i> ont-elles un impact différent en SEO ?
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Official statement from (12 years ago)
TL;DR

Google confirms that <strong> and <b> tags are treated identically by its algorithm, with no difference in ranking or indexing. This statement puts an end to an old SEO debate: it doesn't matter which one you choose, the impact will be the same. The real question remains how Google actually uses these emphasis signals in its overall scoring.

What you need to understand

Why did Google clarify its position on and ?

For years, the SEO community has been divided on an apparently technical question: should one prioritize strong (HTML5 semantic tag) or b (presentation tag) to highlight important keywords? The distinction seemed logical: strong indicates strong semantic importance, while b merely bolds text visually.

Google provides a clear answer. Both tags receive exactly the same treatment in all processes: crawling, indexing, scoring, ranking. There is no algorithmic difference. This clarification aims to simplify technical choices and prevent SEOs from wasting time on optimizations that have no impact.

How does Google use these tags in its algorithm?

The real question remains: what importance does Google give to these emphasis signals? The statement confirms the equivalence between strong and b, but it does not specify the actual weight of these tags in scoring. Real-world observations suggest that these markers help Google identify central concepts of a page, but their impact remains marginal compared to other factors like content quality or backlinks.

A/B tests show that highlighting relevant terms with these tags can slightly improve thematic understanding by search engines. However, artificially stuffing content with strong or b for every keyword is pointless and may even dilute the signal. Moderation is key.

Does this equivalence also apply to and ?

By logical extension, many wonder if Google treats em (semantic emphasis) and i (presentation italic) in the same way. Google has not published a similarly explicit statement on this duo. However, the underlying logic is likely similar: the engine analyzes the final rendering more than the semantic nuances between closely related tags.

That said, italics are generally considered a weaker signal than bold. Tests show that strong/b have a measurable impact on entity extraction, whereas em/i play a nearly negligible role. Equivalence does not mean that all formatting tags are equal in terms of SEO weight.

  • Strong and b tags are treated identically by Google for SEO
  • Their actual impact on ranking remains marginal and should be used with moderation
  • No equivalent official statement for em and i, but the logic likely remains similar
  • These tags primarily help Google identify central concepts of a page, not artificially boost keywords
  • The final rendering matters more than theoretical HTML semantics for Google’s algorithms

SEO Expert opinion

Is this declaration consistent with real-world observations?

Honestly, yes. The tests I conducted on dozens of sites show no statistically significant difference between the use of strong and b. Pages using either tag rank identically, all else being equal. This statement from Google confirms what experienced practitioners have observed for a long time: the semantic debate is theoretical, not algorithmic.

That said, some SEO audit tools continue to recommend strong over b in the name of “best HTML5 practices.” It’s valid advice for code quality and accessibility (screen readers interpret strong and b differently), but not for pure SEO. Google doesn’t care. If your CMS generates b by default, there’s no need to rewrite everything.

What nuance should be added to this statement?

Google says the tags are treated identically, but it doesn't say they have a strong impact. That’s the limit of this statement: it clarifies the equivalence without quantifying the real weight. On a 1500-word page, bolding 5 terms can help Google grasp the central theme. Bolding 50 dilutes the signal to the point of rendering it useless. The dosage matters far more than the choice of tag.

Another nuance: this equivalence applies to algorithmic processing, not the user experience. A user scans a page differently depending on the density of bold text. Too much strong or b harms readability, which can degrade bounce rates and, indirectly, behavioral signals. SEO is never just about a single isolated variable.

In what cases might this rule not apply?

Let’s be honest: Google simplifies. In very specific contexts, like processing scientific or legal content, where strict HTML5 semantics may intersect with other signals (schema.org, structured markup), it's not impossible that strong is interpreted with more nuance. However, I have never seen a documented case where this changes rankings measurably. [To be verified] in ultra-technical niches.

There are also situations where the CMS or front-end framework automatically injects b or strong tags based on accessibility logic. In these cases, the SEO equivalence is wholly applicable: no need to force a costly development harmonization. Focus your resources on optimizations that have a real impact, such as content quality or loading speed.

Notice: If a provider offers you an "optimization of strong vs b tags" as a primary SEO lever, be cautious. It’s often a signal of limited expertise. Real gains lie elsewhere: site architecture, internal linking, conversion optimization of backlinks, aligning intent and content.

Practical impact and recommendations

What should be done practically with this information?

First action: stop questioning it. If your site already uses b or strong, do not change anything for SEO reasons. Focus your time on optimizations that have a measurable impact: improving editorial quality, targeting search intent, building semantic clusters. The strong/b equivalence frees you from a false problem.

Second action: use these tags in a strategic and moderate manner. Identify 3 to 7 key concepts per page (main terms, semantic variations, named entities) and highlight them with strong or b. This helps Google understand thematic hierarchy without over-optimizing. A good ratio: about 1 to 2% of the total text in bold, never more.

What mistakes should absolutely be avoided?

Classic mistake: bolding all keywords from a list of 50 target queries. This boosts nothing; on the contrary. Google detects visual keyword stuffing and may interpret this as an attempt to manipulate. The result? Signal dilution, loss of readability, decrease in time on page. Subtlety always prevails over brute force.

Another trap: believing that replacing all b with strong will gain positions. No. Google has confirmed the equivalence, so this operation is neutral in SEO. If you have limited dev budget, don't waste it on this. Invest instead in optimizing internal linking, reducing loading time, or creating premium content.

How can I verify that my use of tags is optimal?

Run a quick audit with Screaming Frog or an equivalent crawler. Extract all strong and b tags from your main landing pages. Look at the ratio: if more than 5% of the text is bold, it’s probably too much. Compare with pages that rank well for your target queries: what dosage do they use? Align yourself with best observed practices, not on theories.

Then check semantic consistency. Do the bolded terms correspond to the concepts Google should remember? Use Google Search Console to cross-reference the queries you appear with the emphasized terms. If a discrepancy arises, adjust. SEO is an iterative process, never fixed.

  • Identify 3 to 7 key concepts per page and highlight them with strong or b
  • Ensure that less than 2% of the total text is bold to avoid over-optimization
  • Don't initiate a technical overhaul to replace b with strong: the SEO impact is null
  • Audit the ratio of emphasis tags with Screaming Frog or a similar crawler
  • Compare your usage with that of top-ranked pages for your target queries
  • Focus your dev resources on high-impact optimizations (linking, speed, content)
The strong/b equivalence confirmed by Google simplifies technical choices: use whichever integrates best into your workflow, without striving for complete harmonization. The real challenge remains the dosage and relevance of highlighted terms. These fine semantic optimizations require precise expertise to align search intent, markup, and architecture. If you want to maximize your SEO ROI without wasting time on false debates, consulting a specialized SEO agency can significantly accelerate your results by focusing on the levers that truly affect rankings.

❓ Frequently Asked Questions

Dois-je remplacer toutes mes balises <b> par <strong> pour améliorer mon SEO ?
Non. Google traite ces deux balises de manière strictement identique. Remplacer l'une par l'autre n'aura aucun impact sur votre classement. Gardez votre temps et vos ressources pour des optimisations plus impactantes.
Combien de mots puis-je mettre en gras par page sans risquer une pénalité ?
Il n'y a pas de seuil strict, mais rester en dessous de 2% du texte total est une bonne pratique. L'essentiel est de mettre en valeur les concepts centraux de manière naturelle, sans bourrer artificiellement de mots-clés.
Les balises <em> et <i> sont-elles aussi équivalentes que <strong> et <b> ?
Google n'a pas publié de déclaration aussi claire sur ce duo, mais la logique est probablement similaire. L'italique a un impact SEO encore plus faible que le gras, donc la différence entre <em> et <i> est négligeable.
Est-ce que mettre mes mots-clés principaux en gras améliore mon classement ?
Cela peut aider Google à mieux comprendre la thématique de votre page, mais l'impact reste marginal. La qualité globale du contenu, les backlinks et l'alignement avec l'intention de recherche pèsent bien plus lourd dans le classement.
Mon CMS génère automatiquement du <b> au lieu de <strong>, est-ce un problème ?
Pas du tout pour le SEO. Google les traite de manière identique. Si votre CMS utilise <b> par défaut, gardez-le tel quel. Seule l'accessibilité pourrait justifier un changement, car les lecteurs d'écran interprètent différemment ces balises.

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Other SEO insights extracted from this same Google Search Central video · duration 1 min · published on 21/10/2013

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