Resources · Measuring AI Visibility

Can Semrush, Ahrefs, or Moz Detect LLM Hallucinations and Omissions?

They detect omissions well and hallucinations only with your help. All three show where competitors appear in AI answers and you do not, and all three let you read the answers and the sources behind them. None of them automatically checks answers against your facts. Semrush's Perception and Narrative Drivers reports, Ahrefs Brand Radar's response filters and Moz's AI Visibility dashboard help you find errors. A person, or a separate tool, still has to judge whether a claim is wrong. Some dedicated AI visibility tools, such as Profound's FactCheck and seoClarity's ArcAI, do flag inaccurate claims. If accuracy is your main worry, pair one of the three with a simple fact check.

What counts as a hallucination or an omission?

It helps to separate four problems, because tools handle them differently:

  • Fabricated details: features, prices or policies you never had.
  • Outdated facts: old prices, discontinued products, former addresses.
  • Misattribution: a competitor's feature, review or problem attached to you.
  • Omissions: either you are missing from answers where competitors appear, or you appear but key products or strengths are left out.

The first three need a comparison with your own facts. The first kind of omission only needs counting, which trackers do well. The second kind needs reading.

What can each tool do?

From each vendor's product pages, help and blog posts:

Semrush AI Visibility Toolkit Ahrefs Brand Radar Moz Pro AI Visibility
Read full answers and sources Yes Yes Yes (Prompts tab shows each response with cited pages)
Sentiment Yes Not in Brand Radar; judged by reading answers Yes
How AI describes you Perception report of attributes Filter answers by what they contain Visibility and position
Where false claims come from Narrative Drivers shows sources shaping your narrative Cited domains and pages reports Sources referenced for your prompts
Omission: competitors appear, you do not Competitor comparison by prompt "Others only" report Competitor benchmark
Automatic fact check against your data Not described Not described Not described
Engines ChatGPT Search, AI Mode, Gemini daily; Perplexity in weekly brand reports AI Overviews, AI Mode, ChatGPT, Perplexity, Gemini, Copilot (Grok collection paused); Claude on custom prompts ChatGPT, Gemini, AI Mode, Perplexity
Entry price $99/mo per domain Custom prompts from $50/mo with no Ahrefs plan; market indexes from $199/mo per platform Moz Pro Standard $99/mo, 150 prompts weekly

How does Semrush help find errors?

Semrush's guidance on AI misinformation recommends two reports in its AI Visibility Toolkit. Perception shows the attributes AI platforms associate with your brand, so you can spot claims that do not match your product. Narrative Drivers shows which sources shape how AI describes you, so you can trace a wrong claim to the review, forum thread or article feeding it. You can open the full response for any prompt, with sources. Semrush's own advice is to review those answers for incorrect information and ask sources to update it, which is a manual step.

How does Ahrefs Brand Radar help?

Brand Radar's strength is filtering a very large set of answers. Ahrefs suggests several searches:

  • Branded questions whose answers leave you out (the question contains your brand, the answer does not), which Ahrefs says indicates a perception problem.
  • Answers about your topic where only competitors appear, through the "Others only" report, which surfaces omissions.
  • Answers that mention you, in the AI responses tab, read for inaccuracies, outdated messages and sentiment.

Its cited pages report shows which third-party pages AI draws on for your brand, where Ahrefs recommends checking accuracy and freshness. Ahrefs frames this as finding patterns yourself; there is no automatic accuracy flag. More on its reporting is in Ahrefs Brand Radar vs Semrush.

How does Moz help?

Moz Pro's AI Visibility dashboard, on the Standard plan and above, measures how often and how early your brand appears in answers across ChatGPT, Gemini, Google AI Mode and Perplexity. It compares you with competitors and shows the pages and sites referenced in answers to your tracked prompts. Its Prompts tab also shows the full response for each tracked prompt, which you can read for wrong claims. That makes it useful for omissions and for finding the sources AI trusts in your industry. It includes sentiment analysis, which shows whether answers discuss you favourably, but it does not describe features for checking claims, so hallucination checks need a separate process.

Which tools do check facts automatically?

A few AI visibility platforms compare answers with known facts and flag errors. Profound's FactCheck flags inaccurate claims and their sources. seoClarity's ArcAI detects hallucinations and errors and traces them to sources. AthenaHQ offers claim review and discrepancy detection on its Enterprise plan. Peec AI's self-serve plans also list prompt fact-checking. Smaller tools such as Waikay focus on checking facts about brands, covered in the Waikay review. These still depend on the facts you give them, so keep your source of truth current.

How can you build a reliable check with Semrush, Ahrefs or Moz?

  1. Write a fact sheet: current prices, products, locations, key features, leadership and policies, with dates.
  2. Pick 20 to 30 prompts likely to surface facts, such as pricing, comparisons and "does [brand] offer...".
  3. Export or copy the full answers from your tool each month.
  4. Check each answer against the fact sheet, by hand or with a simple spreadsheet search for key terms and numbers. Mark each claim as correct, wrong, outdated or missing.
  5. Trace every error to its source using the tool's source or narrative reports.
  6. Fix at the source, by updating your own pages first, then asking third-party sites to correct theirs.
  7. Re-check the same prompts four to eight weeks later.

Keep a running log of errors and fixes. It becomes the evidence that shows whether accuracy is improving. For a small brand, time one round of checking 25 prompts on three engines this way, and compare that cost with a dedicated fact-checking tool.

Why can't trackers simply flag hallucinations?

Because a tracker does not know your facts. It sees text such as "plans start at $49", but cannot tell whether that is right without a trusted record to compare against. It also cannot always tell a genuine omission from a fair editorial choice. Answers vary between runs as well, so a single wrong answer may not repeat. Checking the same prompts several times, as covered in whether asking LLMs directly is a valid way to measure visibility, separates stable errors from one-off slips.

What might this look like in practice?

Consider an illustrative project software company, Plankline, using Semrush. Its Perception report showed AI describing it as "best for enterprise", while it sold mainly to small teams. Narrative Drivers traced this to a two-year-old comparison article. A monthly fact check of 25 prompts also found ChatGPT quoting a discontinued $15 plan in six answers. Plankline updated its pricing page, asked the comparison site to refresh its article, and found the old price in only one answer two months later.

What do people ask about detecting AI errors?

Does Semrush flag hallucinations automatically?

Not in the AI Visibility Toolkit as described. Its Perception and Narrative Drivers reports help you find and trace errors.

Can Ahrefs Brand Radar show where I am missing?

Yes. Its "Others only" report shows answers about your topic that name only competitors.

Does Moz track sentiment in AI answers?

Yes. Moz Pro's AI plans include sentiment analysis alongside visibility, position, competitors and sources.

Which tools check AI answers against my facts?

Profound's FactCheck, seoClarity's ArcAI, AthenaHQ's Enterprise claim review and specialist tools such as Waikay.

Published by The Kovmere Team · updated Sep 29, 2026 · More resources