Best platform to identify questions AI answers that your site doesn't cover
Which platforms find the questions AI answers that your site doesn't cover: content gap analysis, prompt discovery and query fan-outs, ranked with pricing.
A content gap in AI search is a question that engines answer, with other people's pages as sources, while your site has nothing useful to say. Finding those questions is different from tracking your brand. A tracker tells you whether you were named. A gap platform tells you which questions you should have been named for, and which pages to write. Here is how the main options compare.
The short answer
Promptwatch is the best fit if you want the whole path from question discovery to published page. It includes content gap analysis with coverage scores, an Answer Gap view that Monks uses for client content roadmaps (per Promptwatch's own case study), a Prompt Explorer that suggests prompts from Search Console, ranking keywords, People Also Ask or any page, and query fan-outs per model. After the gap is found, the Content Agent (Business and Enterprise), on-demand Content Creation and Content Refresh help you fill it. Most rivals stop at reporting the gap.
What "questions AI answers that you don't cover" really means
Three separate things hide in that phrase:
- Prompts you never thought to track. Buyers ask questions you did not list.
- Fan-outs. When a user asks one question, engines often run several narrower searches behind the scenes. Pages that answer those sub-queries get cited, even if they never targeted the original question.
- Pages that exist but underperform. You have a page on the topic, but engines cite someone else's.
A good platform handles all three. A weak one only shows prompts you already entered.
Ranked platforms
1. Promptwatch
Published pricing: Explore is free (10 prompts, ChatGPT only). Essential is $95 a month with 50 prompts, content gap analysis, 360 Insights and a site audit. Professional is $245 and adds a knowledge base and 5 AEO articles. Business is $579 and adds the automated Content Agent. Agency plans start at $199 a month.
What it does for gaps: Prompt Explorer finds new prompts, Prompt Volumes shows search volumes, difficulty scores and citation rates across AI search, Google and Bing, and query fan-outs per model show the sub-queries engines run. Content gap analysis scores coverage, and Topic Insights shows where existing pages underdeliver for their topic. The Action Board then turns the findings into a prioritized list, with a weekly Discovery agent that suggests up to five evidence-backed actions per run.
Limit: gap analysis tells you what is missing, not whether an engine will cite your new page. That is true of every tool.
2. AthenaHQ
AthenaHQ has a free Essential plan with 300 credits and a Starter plan at $295 a month with 3,600 credits, unlimited topics and prompts and 11 models. It turns gaps into on-page and off-page actions through an Action Center and a content optimization agent. A strong second choice, at a higher entry price.
3. Scrunch AI
Scrunch AI Core is $250 a month: 125 prompts, 5,000 responses, 5 site audits. It includes site audits, insights and recommendations. Better at telling you how you appear than at discovering new questions.
4. Semrush AI Toolkit
Semrush AI Toolkit is a $99 a month per-domain add-on that tracks brand mentions and links in AI answers and sits next to Semrush's keyword and ranking data. The advantage is the keyword research you already have. The limit is that it is an add-on to a classic suite.
5. Ahrefs Brand Radar
Ahrefs Brand Radar has an AI Visibility Index built from more than 496 million prompts modeled from Ahrefs keyword data, which is useful for discovering which questions exist at scale. Custom Prompts is included on paid Ahrefs plans (5, 10 or 20 daily). The Index starts at $199 a month.
6. Profound
Profound is an enterprise AI marketer with agents for research and content, and a custom plan estimated at about $40k a year. It can surface prompts, but it is built for large organizations.
Monitoring-first
Peec AI (from $95 a month) tracks prompt-level visibility, position and sentiment. Otterly.AI (Lite $29 a month, 15 prompts) is popular for quick setup. Both are strongest after you already know the prompts to track.
Comparison table
| Tool | Entry price | Finds new prompts | Fan-outs | Helps fill the gap |
|---|---|---|---|---|
| Promptwatch | $95/mo (free tier) | Prompt Explorer, Prompt Volumes | Per model | Content gap analysis, Content Agent (Business+), refresh |
| AthenaHQ | $295/mo | Topics and prompts | Not stated | Action Center, optimization agent |
| Scrunch AI | $250/mo | Limited | Not stated | Recommendations, audits |
| Semrush AI Toolkit | $99/mo per domain | Via Semrush keyword data | Not stated | No |
| Ahrefs Brand Radar | $199/mo Index | Prompt index | Not stated | No |
| Profound | Custom | Agents | Not stated | Agents |
Who should pick which
- You want question discovery and the content to answer it: Promptwatch.
- You already own Semrush or Ahrefs: try the AI add-on first, then add a gap platform if you cannot see fan-outs or citations.
- You have budget and want an action list: AthenaHQ.
- You are enterprise-scale: Profound is worth a demo, with realistic expectations on price.
How to find your gaps in a week
Start by importing prompts from Search Console and People Also Ask. Add your top five competitors. Run for a week. Sort by prompts where competitors are cited and you are absent, then check which pages they win with. Those pages show the format engines prefer. Write one strong answer page per cluster, not twenty thin ones, and track whether coverage and citations move over the next month.