Vol. 01 — AI Citation IndexAugust 2026
Citation/Research

Who does AI cite when people ask? We measure it — industry by industry.

¶  AI Citation Index — July 2026

Who does AI cite when America asks about real estate?

We ran 612 real homebuying and selling questions through five AI answer engines — 15,300 answer runs — and recorded every source they cited. This is what we found.

Index № 001 — US Real EstateJul 2026
  1. 1Zillow14.7%
  2. 2Realtor.com11.4%
  3. 3Redfin9.5%
  4. 4Investopedia7.7%
  5. 5Reddit6.6%

n = 15,300 runs · ±1.2 pp · CC-BY 4.0

612

Prompts tested

Weighted by real search demand

15,300

Answer runs

5 runs per prompt per platform

5

AI platforms

ChatGPT, AIO, Perplexity, Copilot, Claude

41,286

Citations captured

±1.2 pp at 95% confidence

Zillow14.7%0.8Realtor.com11.4%0.3Redfin9.5%0.4Investopedia7.7%0.2Reddit6.6%1.1Bankrate5.9%0.2NAR4.5%0.1NerdWallet4.1%0.3Homes.com3.8%0.5HUD3.5%0.2Rocket Mortgage2.9%0.1Wikipedia2.7%0.4
01

The ranking

July 2026 — top 10 of 1,912 cited domains

#SourceCitation shareΔ Jun
1Zillowzillow.com14.7%-0.8 pp
2Realtor.comrealtor.com11.4%-0.3 pp
3Redfinredfin.com9.5%+0.4 pp
4Investopediainvestopedia.com7.7%+0.2 pp
5Redditreddit.com6.6%+1.1 pp
6Bankratebankrate.com5.9%-0.2 pp
7NARnar.realtor4.5%+0.1 pp
8NerdWalletnerdwallet.com4.1%+0.3 pp
9Homes.comhomes.com3.8%+0.5 pp
10HUDhud.gov3.5%+0.2 pp
02

What the data says

Key findings

  1. Finding 01

    The portal triopoly is loosening

    Zillow, Realtor.com and Redfin still absorb 35.6% of all citations, but their combined share is down 3.1 pp since February. The losses are not going to other portals — they are going to community discussions and video, which grew from 19.1% to 22.4% over the same period.

  2. Finding 02

    Each AI engine has a distinct sourcing personality

    ChatGPT over-indexes on reference content (Wikipedia 3.9%, Investopedia 8.9%). AI Overviews routes 3.2× more citations to community and video than ChatGPT. Claude is the most institutional, favoring government and association sources. A brand's AI visibility strategy cannot be platform-agnostic.

  3. Finding 03

    Guides beat listings on informational intent

    For how-to and definitional prompts — 58% of the corpus — explainer content captures 41% of citations while listing pages capture just 9%. Listing pages only win when intent is explicitly transactional. Content type, not domain authority, is the strongest predictor of citation on informational prompts.

03

Coverage

Industries under measurement

IndustryStatusPrompt corpus
US Real Estate● Live612View →
US Health Insurance◐ Collecting540
Consumer Banking○ Q4 2026
B2B SaaS○ Q4 2026
US Travel○ Q1 2027

One industry goes deep every month. New verticals are chosen by reader vote and data availability — the pipeline runs identically for each.

04

Radical methodology

Every number on this site comes from a published, repeatable protocol: a prompt corpus weighted by real search demand, five answer runs per prompt per platform, deterministic citation extraction, and monthly re-runs from a frozen prompt set. No screenshots, no anecdotes — and we publish our confidence intervals.

Read the full protocol →

Underlying dataset

citations.csv41,286 rows

prompts.csv612 rows

domains.parquet1,912 domains

methodology.pdf14 pages

Free with email. CC-BY 4.0 — cite us, reuse freely.

Free visibility scan

Is AI citing your brand — or your competitor?

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