Google Query Expansion: How Google Understands and Expands Your Search

Published on 8/14/2025

Summarize this article:

How Google Expands Your Search

Quick Overview

When you type a search into Google, the system does more than just look for pages with those exact words. It expands your query to include related words, phrases, and variations so it can give better results.

  1. Google can spot different spellings of the same word or synonyms.

    • “colour” → also searches for “color”
    • “tall buildings” → also searches for “skyscraper,” “tower”

  2. Acronyms are interpreted.

    • “LA” → could mean Los Angeles
    • “diy” → recognized as “do it yourself”

  3. Singular/plural variations are recognized.

    • “car” → also finds “cars”

  4. Translated versions of words may be included.

    • “buy car” → Google may also search for “acheter car” if you’re in France

  5. Frequent phrases (bi-grams or tri-grams) are detected and combined.

    • “Mexican restaurant” → recognized as “mexicanrestaurant”

  6. Google uses your location and geographic codes to match local results.

    • “Miami” → can also include “South FL”

  7. Google expands your query semantically too

    • “How to” → diy (do it yourself)

Examples of Google Query Expansion

  1. Query: “tallest building in the world”

    Query WordRelated / Expanded Terms
    tallesthighest, iv;d;highest, tall buildings
    buildingbuildings, iv;d;building, iv;d;buildings, iv;d;structure, iv;d;tower, skyscraper, structure, structures, tall buildings, tower
    in(stop word – ignored)
    worldearth, ever, global, iv;d;earth, iv;d;ever, iv;d;global, iv;d;world, top 10, whats, worlds

    Detected frequent bi-gram: tall buildings Generated expansions: skyscraper, tower, highest, top 10

  2. Query: “how to build sandcastle”

    Query WordRelated / Expanded Terms
    howdiy, plans, how, iv;d;how, iv;d;diy, iv;d;plans
    to(stop word – ignored)
    buildbuilt, building, develop, diy, construct, create, do you make, creating, establish, form
    sandcastlesandcastle, sandcastles

    Detected frequent bi-gram: sand castle Semantic expansions: diy General expansions: sandcastles, diy, creating, construct

Credit: Examples adapted from RESONEO – Query Expansion & Mysterious Scoring

Understanding iv;p and iv;d in Google Query Expansion

When Google looks at the words in your search, it sometimes tags them with codes to decide how closely it should match them in results.

  • iv;p – Exact match
    Google will only look for pages that have the exact same word you typed, with no changes.
    Example: if you type “building,” it will only match “building” exactly.

  • iv;d – Derived form match
    Google will also allow variations of the word, such as different endings or closely related words.
    Example: if you type “building,” it might also match “buildings,” “build,” or “structure.”

  • Unmarked words – Flexible match
    Google is free to match related meanings, synonyms, or even different spellings.
    Example: if you type “building,” it might also look for “skyscraper” or “tower.”

Scoring in Google Search

Among the many factors Google uses to rank pages, one is how well each word in your search matches a page.

  • Every word in your search gets its own score for each page.
  • The same word can have a different score for the same page in different searches, because the meaning and context of your query changes.
  • Whether the word appears in the page’s title, URL, or main text affects its score.
  • This score is only an early step — other signals like click data, freshness, and content quality can change the final ranking.