Semrush Keyword and Backlink Database Numbers – Are 28.9B Keywords and 43 Trillion Backlinks Real?

It’s easy to be wowed by the staggering figures some SEO tools throw around. Semrush, one of the biggest names in digital marketing intelligence, claims a 28.9 billion keyword database and a mind-boggling 43 trillion backlink index. But the question is: are these numbers real? More importantly, how do these figures translate into actionable insights within the platform's workflow?

In this post, we’ll unpack Semrush's data size claims, compare them within the industry context, and explore how they stack up against emerging AI-driven alternatives like Otterly.ai and AthenaHQ. Along the way, I’ll highlight important considerations around AI visibility vs SEO rank tracking, engine coverage and crucial add-ons, pricing transparency with prompt limits, and the often-overlooked need for prompt tracking and daily monitoring.

Understanding Semrush Data Size: 28.9B Keywords and 43 Trillion Backlinks

Semrush’s marketing pushes enormous numbers to emphasize their coverage depth. Here’s what’s being claimed:

28.9 billion keywords: Semrush advertises nearly 29 billion keywords in its combined search engine databases worldwide. This covers traditional search engines like Google, Bing, Baidu, and others spanning dozens of countries and languages.
43 trillion backlinks: Their backlink index is claimed to be larger than many competitors, with 43 trillion backlinks crawled and indexed.

Are these numbers realistic? Yes, but with caveats:

Data aggregation: Semrush compiles keyword data from multiple sources, including their proprietary crawlers, third-party providers, and partnerships. Their 28.9B figure aggregates all keywords tracked globally, including exact match, related terms, and question-based queries documented across verticals.
Backlink duplication: The 43 trillion backlinks count includes all discovered links, many of which are duplicates or temporary. They scan the web at scale, so the backlink count massively inflates accordingly.
Frequency and freshness: The sheer volume means not all data is updated continuously. Semrush prioritizes high-impact keywords and backlinks for frequent refreshes while lower-traffic data may lag.

So the numbers are real in the sense of raw crawl and storage scale, but marketers should understand that working with the entire dataset is not practical. That’s where filtering, ranking, and AI analysis come in.

Why Knowing Semrush Data Size Matters for Your SEO and Marketing Efforts

When you pay for an SEO tool, it’s not about how big the database is; rather, it is about the quality of insights you get and how those insights help you act faster and smarter in your campaigns.

Here are some reasons to care about data scale — but also be cautious:

Broader Keyword Coverage: A larger database reduces the chances of missing long-tail and low-volume keywords. But it’s critical to see whether your vertical and geography are well-covered.
Backlink Authority Insights: A massive backlink index improves the tool’s backlink quality signal through link context and frequency. However, if the tool treats all backlinks equally, the volume alone becomes less helpful.
Historical Trends: Bigger datasets can support accurate trend analysis and help forecast SEO success or challenges more confidently.
AI Visibility vs SEO Rank Tracking: Semrush’s new AI Visibility Toolkit starts at $139/month, showcasing a push beyond traditional rank tracking into predictive analytics and AI-driven site performance visibility.

AI Visibility Toolkit: New Frontier or Feature Gimmick?

The AI Visibility Toolkit from Semrush is priced starting at $139/month, positioning itself as a next-gen solution that blends traditional SEO rankings with AI-powered performance signals and competitive benchmarking. While it’s exciting, let’s break down these elements:

Feature Description Typical Use Case AI-driven Content Optimization Recommends copy improvements based on semantic analysis Content teams refining SEO and semantic relevance Predictive Ranking Signals Combines keyword data with AI models to forecast ranking movements SEO teams planning optimization timelines Churn Detection & Competitor Monitoring Flags losing keywords and competitor breakthroughs Marketing ops focusing on competitive intelligence

This shift toward AI visibility is reflected in competitive tools like Otterly.ai and AthenaHQ, which incorporate AI-generated insights with traditional keyword and backlink data for more digestible, actionable dashboards.

Engine Coverage and Add-ons: What’s Behind the Numbers?

One area where Semrush transparently excels is their extensive engine coverage, but there’s important nuance here:

Multiple Search Engines: Semrush indexes Google across 142 countries, Bing, Baidu, Yandex, and more.
Paid Add-ons: Some advanced reports, API access, and VPS-based crawl emulation come with extra pricing layers.
Prompt Limits with AI Models: The AI toolkit uses underlying large language models with API call limits per subscription tier. Semrush doesn’t prominently disclose these prompt limits, which can affect day-to-day usage.

This is where emerging AI-native competitors shine by offering transparent usage tiers and prompt tracking dashboards—critical for controlling costs if you integrate AI into your content generation or SEO workflows.

Pricing Transparency: A Marketer’s Pet Peeve

One gripe I often have with major platform vendor evaluations is vague "contact sales" pricing pages. Semrush does better than many with published tier prices, but there’s still some opacity around:

What add-ons are included by default vs those requiring an upgrade.
How prompt limits for AI features translate to real-world volume for content teams.
Coverage granularity for emerging markets and verticals.

By contrast, companies like Otterly.ai often publish per-prompt or monthly usage pricing upfront, enabling faster budget decisions for marketing leaders.

Prompt Tracking and Daily Monitoring: The Missing Pieces from Many Dashboards

Here’s an area where tools including Semrush, ChatGPT, and Perplexity could improve: translating raw data and AI-driven insights into actionable prompts that are monitored daily for performance impact.

For example, if you integrate Semrush’s AI Visibility toolkit with ChatGPT to generate optimized content briefs, how do you track prompt effectiveness over time? Which keywords saw actual ranking improvements, and when? Where do backlink quality signals from a 43 trillion backlink database feed into your alerting system to catch potential threats?

Marketers deserve unified dashboards that:

Link prompt input with ranking and backlink outcome metrics
Highlight anomalies or sudden shifts in visibility via daily automated monitoring
Encourage iteration by surfacing which AI suggestions yielded tangible SEO improvements

Tools like AthenaHQ are exploring these integrations by combining historic SEO data with modern AI prompt tracking, but Semrush has room to enhance this aspect.

Summary: So, Are Semrush's 28.9B Keywords and 43 Trillion Backlinks Real?

Yes, but with context:

The massive scale reflects comprehensive data gathering, but marketers do not work with all 28.9 billion keywords daily.
Backlink numbers include duplicates and all link forms—it’s about quality signals layered on top.
Semrush’s AI Visibility Toolkit marks a promising evolution from plain rank tracking toward AI-powered prediction and content optimization, starting at $139/month.
Transparent pricing and prompt limits remain a challenge to fully understanding ROI in AI features, a gap competitors like Otterly.ai are aiming to address.
Integrating prompt tracking and daily monitoring will be critical for turning raw data and AI insights into a marketer’s operational advantage—something all vendors, including Semrush and newer tools like AthenaHQ, are still refining.

In the seosandwitch end, Semrush’s data size claims hold up as large-scale crawl and index volumes. But savvy marketers know it’s the platform’s intelligence layer—the filtering, AI analysis, and actionable integrations—that really matter.