Do Backlinks Nonetheless Matter in AI Search? Insights from 1,000 Domains [Study]

For years, backlinks have been one of many strongest indicators driving rankings in conventional search.

However have the principles modified as we enter the brand new period of AI search?

Along with Kevin Indig, we have run an information research to look at how backlinks affect visibility in AI-generated solutions.

Let’s dive in.

Key Takeaways

TL;DR: Backlinks are vital for AI visibility, however high quality and authority matter excess of amount.

• Excessive-quality backlinks matter greater than sheer quantity. Domains with stronger backlink authority—measured by Semrush’s Authority Rating—are talked about extra usually in AI-generated solutions. That mentioned, massive visibility positive aspects solely seem as soon as a web site reaches the upper authority tiers.

• Nofollow hyperlinks have practically the identical affect as observe hyperlinks. The research discovered comparable correlation values for each varieties, with main positive aspects showing solely within the prime tiers of authority.

• Picture-based backlinks will be simply as highly effective as textual content hyperlinks. As soon as a web site already has some authority, picture hyperlinks present even stronger correlations with AI mentions than textual content hyperlinks—particularly for higher-authority domains.

Methodology

We carried out this research in collaboration with Kevin Indig and Progress Memo.

First, we checked out 1,000 randomly chosen domains inside Semrush’s AI Visibility Toolkit to grasp how backlink-related indicators affect visibility in AI-generated solutions.

To that finish, we tracked how usually every area was talked about throughout 5 main AI platforms:

• ChatGPT
• ChatGPT with Search
• Gemini
• Google’s AI Overviews
• Perplexity

We then in contrast the variety of AI mentions (what number of occasions a site was referenced throughout AI-generated solutions) and AI Share of Voice (a site’s visibility in AI-generated solutions relative to non-branded queries) towards key backlink indicators:

• Complete variety of backlinks
• Variety of distinctive referring domains
• Ratio of observe vs. nofollow hyperlinks
• Textual content hyperlinks vs. picture hyperlinks
• Authority Rating—Semrush’s composite metric that displays backlink high quality, referring area range, natural site visitors to linking pages, and spam indicators

Lastly, we ran Pearson and Spearman correlation analyses on the identical dataset to look at how strongly every backlink sign was related to AI visibility—and to establish whether or not these relationships had been linear or confirmed threshold results.

Study extra about how we measured the correlations.

Right here’s what we discovered.

1. Authority Boosts AI Visibility, However Solely Past a Threshold

Domains with greater Authority Scores—a metric closely influenced by backlink high quality and referring area range—usually tend to seem in AI-generated solutions.

Nevertheless, the impact is reasonable total and solely turns into important as soon as a site crosses into greater authority tiers.

After we in contrast Authority Rating to AI Share of Voice (that’s, a model’s visibility in AI-generated solutions relative to non-branded queries), the outcomes confirmed the next:

• Pearson: ~0.23 → a modest linear relationship
• Spearman: ~0.36 → a stronger, threshold-based sign

The hole between these two correlations reveals that backlink authority has a reasonable total affect on AI visibility, however actual positive aspects seem solely after reaching sure authority ranges. 

In different phrases, incremental backlink enhancements received’t transfer the needle a lot till a web site reaches stronger total authority.

“The large takeaway right here is that your backlink must hit a minimal threshold. In easy phrases: Don’t anticipate returns while you simply get began or from linear progress. You want a minimal funding to see the anticipated affect.”

Kevin Indig, Progress Advisor 

What This Means for You:

• Deal with breaking authority plateaus. Small hyperlink wins received’t make a visual distinction. To maneuver up, give attention to incomes backlinks from higher-authority, topically related websites, comparable to well-known publications, main blogs, or business directories. 

• Increase your pool of referring areas. Getting hyperlinks from quite a lot of completely different web sites issues greater than the sheer quantity of hyperlinks. Prioritize outreach to new domains in your area relatively than gathering extra hyperlinks from the identical sources. 

• Stability authority with credibility. Backlinks assist, however AI fashions additionally favor manufacturers seen as reliable and credible. Maintain content material correct, present, and well-sourced, and goal for mentions from respected websites—even with out hyperlinks—to strengthen your authority.

2. Hyperlink High quality Drives AI Visibility Extra Than Quantity

The standard of backlinks performs a significant function in how usually a site seems in AI-generated solutions.

After we in contrast Authority Rating (Semrush’s proxy for hyperlink high quality) with the variety of AI mentions, the outcomes confirmed a robust constructive relationship:

• Pearson: 0.65 → robust linear correlation
• Spearman: 0.57 → robust however barely non-linear correlation

This implies domains with high-quality backlink profiles seem way more usually in AI-generated solutions, particularly as soon as they cross key authority thresholds.

Apparently, the impact varies throughout fashions: ChatGPT Search and Perplexity weigh hyperlink high quality the least, whereas common ChatGPT (with out Search on) reveals the strongest correlation.

What This Means for You

• Prioritize hyperlink high quality over quantity. A couple of backlinks from authoritative, related web sites will drive way more AI visibility than dozens of weak or unrelated ones.
• Audit your backlink profile frequently. Use instruments like Semrush’s Backlink Analytics to pinpoint which domains are including actual authority, versus low-value or spammy ones that might maintain you again.

• Pursue significant authority positive aspects. As a substitute of chasing small hyperlink exchanges or low-value mentions, goal alternatives that genuinely increase credibility, comparable to digital PR, professional visitor articles, or inclusion in trusted business sources.

3. Nofollow Hyperlinks Carry Virtually as A lot Weight as Observe Hyperlinks

Nofollow hyperlinks have practically the identical affect on AI visibility as commonplace observe hyperlinks.

After we in contrast each (individually) to AI mentions, the correlations had been virtually equivalent.

Observe hyperlinks:

• Pearson: 0.334 → reasonable linear sign
• Spearman: 0.504 → robust threshold sign

Nofollow hyperlinks:

• Pearson: 0.340 → reasonable linear sign
• Spearman: 0.509 → robust threshold sign

This reveals that AI fashions deal with each hyperlink varieties equally when evaluating authority and visibility.

The weighting additionally varies barely by platform: we discovered that Gemini and ChatGPT are likely to favor nofollow hyperlinks a bit extra, whereas Google AI Overviews and Perplexity lean extra towards observe hyperlinks.

What This Means for You:

• Don’t overlook nofollow hyperlinks. They contribute meaningfully to AI visibility, particularly once they come from high-authority websites. Keep in mind: Getting talked about by an authoritative and related supply is extra vital than chasing fast positive aspects.
• Look ahead to platform nuances and diversify your technique. Platforms like Gemini and ChatGPT might reward robust nofollow hyperlinks (e.g., from Reddit, Quora, or Wikipedia), whereas Google AI Overviews and Perplexity nonetheless lean barely towards observe hyperlinks.
• Maintain your hyperlinks—together with nofollow ones—recent and related. Frequently replace content material on pages the place your model already has nofollow mentions.

“Identical to you replace weblog posts, replace nofollow placements. Rotate in new knowledge factors, replace product screenshots, or refresh stats on contributed articles your model has earned nofollow hyperlinks with, so hyperlinks stay related and referenced.”

Kevin Indig, Progress Advisor 

4. Picture Hyperlinks Carry out as Properly as (and Typically Higher Than) Textual content Hyperlinks

Picture-based hyperlinks present a stronger relationship with AI visibility than textual content hyperlinks.

After we in contrast the 2 (individually) to AI mentions, the correlations had been clear.

Picture hyperlinks:

• Pearson: 0.415 → stronger linear sign
• Spearman: 0.538 → robust threshold sign

Textual content hyperlinks:

• Pearson: 0.334 → reasonable linear sign
• Spearman: 0.472 → reasonable threshold sign

The benefit of picture hyperlinks additionally seems as soon as a web site has constructed some authority. 

From mid-level deciles upward, the connection strengthens and peaks on the prime, whereas low-authority tiers present little to no impact.

We additionally seen a number of variations throughout platforms:

• Perplexity and ChatGPT Search present the strongest hyperlink between picture backlinks and AI visibility
• ChatGPT and Gemini observe with barely weaker correlations
• Google AI Overviews reveals the weakest connection, although it’s nonetheless noticeable

Total, image-based backlinks are handled as dependable reference indicators throughout giant language fashions—delivering the largest visibility boosts as soon as a site reaches greater authority ranges.

What This Means for You:

• Put money into attracting image-based hyperlinks. Distribute your visuals the place publishers and creators search for reference materials, with easy-to-copy embed codes or supply credit. Share them on platforms comparable to Reddit, LinkedIn, and business newsletters the place journalists and content material groups supply visuals.
• Deal with including worth. Create helpful picture property based mostly on unique analysis, comparable to charts, infographics, product visuals, and knowledge diagrams that others will naturally embed and hyperlink to.

“Cease treating photographs as equipment and begin treating them as content material. The very best visible content material explains and simplifies important or advanced subjects.”

Kevin Indig, Progress Advisor 

Backlinks Nonetheless Matter, However High quality Trumps Amount in AI Search

Our research reveals a transparent shift in how backlinks affect visibility: high quality is king within the AI period.

As a substitute of making an attempt to gather as many hyperlinks as potential and to “hack” the system, you could give attention to constructing high quality indicators and breaking via authority thresholds.

Right here’s what you must do:

• Prioritize significant authority positive aspects over incremental hyperlink constructing
• Do not dismiss nofollow hyperlinks from high-authority sources
• Put money into shareable visible property that earn image-based hyperlinks
• Deal with getting talked about and cited for content material that genuinely provides worth

The underside line: AI visibility comes from sustained authority, not one-off hyperlink wins. Prioritize incomes high-quality backlinks that transfer your web site into stronger authority ranges and preserve your model referenced on credible, up-to-date sources.

How we measured the correlations

To grasp how backlinks and AI visibility are related, we used two commonplace statistical measures: Pearson and Spearman correlations.

• Pearson checks for a linear relationship between two variables. If each values rise or fall collectively in a easy sample, Pearson picks that up clearly. But when the connection solely turns into seen after hitting a sure level (a threshold), Pearson tends to overlook it.
• Spearman focuses on these threshold results. It appears at whether or not the values transfer in the identical course, even when the curve isn’t completely easy. Spearman is much less delicate to outliers and higher at recognizing conditions the place nothing occurs for some time. Then the connection all of the sudden strengthens after a sure degree is crossed.

Each Pearson and Spearman give a rating between -1 and +1:

• Nearer to +1 → robust constructive relationship
• Nearer to -1 → robust damaging relationship
• Round 0 → little to no relationship

each helped us reveal whether or not the connection between numerous elements is linear or threshold-based.