In normal indexing, search engines treat the full page as a single unit. But with passage indexing, Google can rank a matching snippet of text found deep inside that page—even if the page’s main topic is different. This upgrade makes it easier to find needle-in-a-haystack answers for long or detailed questions, also known as long-tail queries.

The change confused many at first. Some thought Google was storing each passage separately. But that is not true. Google still indexes the entire page. The difference is in how it ranks relevance. A page gets one index entry, but Google can now pick a small part of it and rank that part if it fits the search query best.

Google later clarified this update as a ranking change, not a shift in how pages are indexed. The company prefers the term passage ranking, though the older phrase passage indexing is still common in the SEO world.

This improvement impacted roughly 7 percent of search queries worldwide at the time of launch, making it easier for users to find specific information inside large articles.

How did passage indexing start at Google

Google introduced passage indexing in October 2020 during its Search On event as part of its push to improve how search understands language. This update was aimed at solving a specific problem: users often search for something very detailed, and the answer might be a single sentence hidden deep inside a long article.

To fix this, Google announced a new way to handle such queries using natural language processing. The system could now find that one useful line and rank it directly, instead of missing it because the page was not focused on that exact topic.

Global Impact and Rollout

At launch, Google stated the change would affect about 7 percent of search queries across all languages, making it a major shift in the ranking algorithm. This meant millions of searches every day would start showing better-matched results.

Google began rolling out passage-based ranking in late 2020. On 10 February 2021, it went live for English searches in the United States, and later expanded to more countries and languages over the next few months.

Clarification on Indexing vs Ranking

Google engineers quickly clarified that nothing changed about how pages are indexed. Google still indexes the entire page as one unit. What changed was how its system ranks a passage inside that page when it answers the query better than the overall topic.

Engineers like Martin Splitt and Danny Sullivan pointed out that the term passage indexing was misleading. Google prefers to call it passage ranking, because the update changed ranking logic, not the crawling or indexing process.

Use of NLP and BERT Models

This improvement relied on Google’s advanced natural language processing models. Most important was BERT (Bidirectional Encoder Representations from Transformers), which had already been used since 2019 to better understand both queries and webpage content.

With passage ranking, BERT helped the system detect context inside sections of a page. By 2021, BERT was in use for nearly all English queries, giving Google a more precise way to match a user query with the correct part of a long document.

There was also talk in the industry about another model called SMITH, which could understand longer documents better than BERT. While Google did not officially confirm using SMITH, many believe it helped push these capabilities forward.

How Passage Indexing Works

Passage indexing works as part of Google’s main ranking algorithm, not as a separate feature. When Google crawls a webpage, it still indexes the entire page. But at the same time, its system reviews the page layout and reads the content closely to detect distinct passages.

These passages are not stored separately. They stay within the page’s index entry. But when Google matches a user query, it can score a specific section of the page—almost like a mini-document—based on how well that passage fits the query.

AI and NLP in Passage Understanding

Google uses natural language processing (NLP) and neural networks to understand meaning, context, and structure. The algorithm checks each passage for:

• Keyword relevance
• Semantic signals
• Contextual meaning
• Relation to the query intent

If a small part of a page answers a search clearly, Google can rank the whole page higher just because of that passage.

Martin Splitt from Google explained it as scoring different parts of a page independently, even if the rest of the content is about something else. This gives users a faster way to find answers buried in long pages.

Display in Search Results

When a user searches, Google’s system compares the query not only against full pages, but also against individual passages. If a match is found in a passage, that page may appear in results—often with a featured snippet that highlights the exact text that answers the query.

Sometimes, search results may even link directly to that part of the page. The rest of the content might be on a related topic, but the passage ranking gives weight to the relevant section.

No Special Markup Required

Site owners do not need to add extra tags or change how they write content. Google’s system finds passages automatically. However, using:

• Clear headings
• Logical section breaks
• Simple and structured writing

can help both users and the search engine better understand the content.

Even if a page is poorly organized, Google can still detect passage-level meaning. But a good layout makes this process easier and improves user experience.

How does passage indexing affect Google search results

Passage indexing helps Google show better results for very specific questions, especially when the answer is hidden in a long or unrelated page. This is useful for long-tail queries—detailed searches that are often written in natural language or spoken aloud.

Before this update, if a page did not focus fully on a query, it might not rank at all. Now, Google can find and rank a single paragraph inside a broader page if that part clearly matches the search.

Example of a Long-Tail Query

Google gave an example with the query how can I determine if my house windows are UV glass. Earlier, the top result was a general page about windows. After passage ranking, Google highlighted a forum comment that directly explained the answer, including a test involving flame reflections.

The new result showed this exact passage, bolded in the search snippet, giving users the right information without extra clicks.

Benefit for Users and Publishers

This system improves about 1 in 15 queries, based on Google’s estimates. It means:

• Users see relevant text in the search result itself
• They save time by not scanning multiple links
• Publishers with deep content can rank for more topics

For example, a long article covering many subtopics might now rank for a niche keyword if one of its sections fits that search. Even if the article’s title does not match the query, the relevant part can now appear on the results page.

Not a Featured Snippet, but Similar

Sometimes, these highlighted passages look like featured snippets, but passage indexing works differently. It changes how Google ranks normal results, not how it selects content for the boxed answer. Still, a strong passage might appear in both spots if it answers well.

Changes in Competition

Webpages with rich, long-form content now have more chances to appear in search results. However, short or narrowly focused pages might face extra competition if a larger page includes a well-written answer.

Good structure still helps. But even if the full page is not perfect, a single helpful section can now stand out on its own.

Implications of Passage Indexing for SEO and Content Strategy

Passage indexing has practical effects on SEO practices and how content is written. While Google has stated that no special strategy is needed for this update, it still highlights key areas where SEO and content creation intersect.

Value of Comprehensive Content

Pages with long-form, well-structured content may now appear for more specific search queries. If a single section in a broad article answers a question clearly, that part can help the full page rank. This makes in-depth writing a way to cover multiple subtopics and draw traffic from a wider range of keywords.

Structure Helps Google Understand Content

Although Google can identify passages in unstructured text, having clear headings and sections improves the chance that the right part of a page gets ranked. Use:

• Logical H2 and H3 headings
• One main idea per section
• Headings that reflect user questions

This approach helps both users and algorithms follow the content’s meaning and flow.

Focus on E-E-A-T and User Intent

Google’s system continues to reward content that reflects Experience, Expertise, Authoritativeness, and Trust (E-E-A-T). Even if a page is not tightly optimized for one keyword, it can still rank if it answers real user questions clearly.

Writers should:

• Use natural language
• Cover the topic completely
• Include helpful information, even if it feels like a side point

As long as the content is useful and correct, that section can now support ranking for the right query.

Role of Long-Tail Queries

Passage indexing especially supports long-tail keywords—searches that are longer and more detailed. These often match FAQ-style headings, subtopics, or conversational phrasing. Content creators can increase visibility by writing in a way that answers such niche queries naturally.

On-Page SEO Still Matters

Even though this update reduces the need for exact keyword placement, traditional on-page SEO still helps. Pages with good titles, descriptions, and schema will remain easier to understand and may rank better in competitive topics.

What works best:

• Clear meta titles
• Descriptive summaries
• Proper schema markup
• Readable structure with internal links

Good SEO fundamentals still improve trust and visibility.

Monitoring Performance

Google does not offer a separate report for passage ranking, but changes can be tracked using Google Search Console. You may notice:

• More impressions for niche queries
• Higher clicks on sections that were not targeted before
• Snippets highlighting deeper content

Watch for rising impressions tied to new long-tail phrases. This may signal that one of your passages is now ranking well.

Writing With Flexibility

Writers no longer need to break one topic into many pages. If it makes sense to keep answers together, you can do that. Google can now find and understand those answers even if they appear deep in the page.

This supports a user-first writing style:

• One article can cover the full topic
• Subsections can rank on their own
• Users benefit by finding all answers in one place

How is passage indexing different from snippets

Passage indexing and featured snippets both display parts of a webpage in search results, but they serve different functions in Google Search.

Featured Snippets as Display Elements

A featured snippet is the answer box shown above regular results, often called Position 0. It contains a short answer to a user’s question, along with the page title and URL. These snippets usually respond to queries like definitions, facts, or direct questions—for example, “What is the capital of France?”

Featured snippets are designed to present answers instantly, without requiring the user to click the result. They are chosen for their clarity, brevity, and relevance.

Passage Indexing as a Ranking Signal

In contrast, passage indexing is not a special display format. It is a ranking improvement that helps Google detect the best-matching passage within a longer page. The search result still appears in the standard list, but Google may choose to show a longer snippet or highlight certain text based on passage relevance.

The key idea is that Google now scores individual sections of a page. If a paragraph in the middle of a broad article fits the query best, that page may rank higher—even if it is not focused solely on that topic.

How They Interact

Both systems can work together. If a passage surfaces due to passage indexing, and the query type supports it, that same passage may also be shown as a featured snippet.

However, not all queries trigger snippets. For those searches, passage indexing still improves result quality by lifting pages that have the answer buried in them.

SEO Considerations

From an SEO view:

• Featured snippets are about display visibility
• Passage indexing is about ranking precision

Both benefit from:

• Clear structure
• Short, well-written answers
• Logical sectioning using headings

Content optimized for specific questions and long-tail keywords can perform better under both systems.