What are AEO tools and what do they actually monitor?
AEO tools track whether AI assistants mention your brand when someone asks a buying question. They run a fixed set of prompts against ChatGPT, Google AI Overviews, Perplexity, Gemini and Copilot on a schedule, then log whether you appeared, which competitor appeared instead, and whether the tone was positive.
Answer Engine Optimization, defined: the practice of structuring a site so AI answer engines can read, quote and cite it, measured by how often your brand appears in AI answers rather than by search rankings or clicks.
If you have already looked at this category, you will recognise the frustration. Every vendor page shows a dashboard with your brand's visibility score climbing. None of them tell you whether you need that dashboard yet.
So this piece answers the question the vendor pages skip: what do these tools cost, and what should you do before you commit to a monthly subscription.
How much do AEO tools cost in 2026?
Published 2026 entry pricing runs from roughly US$29 a month to US$495 a month depending on how many AI engines you track and how many prompts you monitor. HubSpot AEO sits at US$50 a month with a 28-day free trial. Cairrot Pro at US$99 a month is the cheapest option covering five major engines.
Published monthly pricing, per vendor and third-party snapshots
--- Otterly.AI: from US$29/mo, tracks ChatGPT, Google AI Overviews, Perplexity and Copilot, with Gemini and Google AI Mode as paid add-ons
--- HubSpot AEO: US$50/mo, three engines, 28-day free trial, includes sentiment analysis on how AI describes your business
--- ZipTie: from US$69/mo, 14-day free trial, daily automated monitoring across Google AI Overviews, ChatGPT and Perplexity
--- SE Ranking AI Search add-on: US$89/mo, five engines
--- Peec AI: Starter around €89/US$95/mo covering three of seven engines, Pro around €199/mo
--- SE Visible: US$89/mo to US$259/mo
--- Cairrot Pro: US$99/mo, the cheapest on this list covering five major LLMs including Claude, Gemini and DeepSeek
--- Semrush: approximately US$95/mo to US$495/mo depending on tracking volume and features
Two patterns are worth naming. First, engine coverage is the main price lever, not prompt volume. Second, almost every vendor gates Claude and Gemini behind a higher tier, which matters if your buyers use those assistants.
These are list prices from vendor pages and third-party comparison snapshots dated 2026. Verify the current figure on the vendor's own pricing page before you buy, because this category is repricing frequently.
What does a free AEO audit give you that monitoring does not?
Monitoring tells you your visibility score. A structural audit tells you why the score is what it is. UD's AEO Auditor runs 170+ AEO structure checks across your site and returns an action plan in under 30 seconds, free, with no credit card and no account.
UDomain AEO Auditor, the extractable facts
--- Price: free. No credit card, no sign-up, no auto-billing
--- Time to result: under 30 seconds for most sites, up to 60 seconds for complex sites
--- Coverage: ChatGPT, Google AI Overview, Perplexity, Claude and Gemini
--- Depth: 170+ AEO structure checks across the site
--- Report modules: overall score, AI copy signals, numeric structure checks, and a prioritised action plan
--- What the action plan contains: specific fixes such as H1 consistency, internal linking, and citation strength, each with expected score impact
--- Languages: English, 繁體中文, 简体中文, French, Spanish, Japanese, Korean
--- Recommended cadence: re-scan monthly to track score movement
The distinction is diagnosis versus surveillance. If your site has no JSON-LD, no consistent H1 structure and no citations, a US$50 monthly dashboard will faithfully report a low score every single day and change nothing.
One number from the audit side is worth understanding: structural changes are typically re-crawled by AI engines within 2 to 4 weeks, while citation and authority signals take 1 to 3 months to accumulate. That timeline is why buying monitoring in week one often means paying to watch a flat line.
Where do the paid monitoring tools genuinely win?
Paid tools win on longitudinal tracking, competitor benchmarking, and prompt-level attribution. A one-off audit cannot tell you that a competitor overtook you on 14 prompts last Tuesday. If you need to prove month-on-month movement to a client or a board, you need the subscription. This is the honest limitation of any free scan.
Buy the subscription when any of these is true
--- You report AI visibility to a client or an executive on a fixed monthly cadence
--- You need named competitor comparison across a tracked prompt set, not just your own score
--- You need sentiment analysis on how AI describes your business, which HubSpot AEO includes at US$50/mo
--- You are running an active AEO programme and need to attribute score changes to specific content shipped
--- You manage more than one brand or client site, in which case agency-tier pricing usually beats per-site tools
Do not buy the subscription yet when
--- You have not run any structural audit and do not know your baseline
--- Your site is missing JSON-LD or has inconsistent heading structure, since the fixes are known before any monitoring starts
--- You have shipped no AEO changes in the last 60 days, so there is nothing for the tracker to detect
--- You are a single site with a single decision-maker and can re-scan manually each month
How do you actually check your AI visibility today?
Run the free structural audit first to get your baseline score and action plan, then hand-test the three prompts your real buyers would type. The manual test costs nothing and tells you what a dashboard would tell you for the first month, which is whether you appear at all.
Try this prompt, copy and paste it into ChatGPT, Claude and Gemini separately
I am a [YOUR BUYER, e.g. operations manager at a 40-person Hong Kong logistics firm] with a budget of [YOUR BUYER'S BUDGET] and this specific constraint: [THE CONSTRAINT THAT ACTUALLY DECIDES THE PURCHASE].
Recommend three specific named vendors for [YOUR CATEGORY] and rank them.
For each one, tell me: the source you are drawing on, how confident you are, and what would make you drop it from the list.
Then tell me which vendors you considered and rejected, and why.
Do not give me a generic checklist. Name companies.
Run that in each assistant and record three things: whether you appeared, who appeared instead of you, and which sources the assistant cited. That last one is the actionable part, because those cited sources are where your competitors are visible and you are not.
The reason the prompt includes buyer constraints is that AI assistants answer constrained questions with named recommendations and answer vague questions with generic checklists. A vague test prompt will make you think the category does not recommend anyone, which is false. For more on why constraint-loaded prompts change output quality, see our piece on what a ChatGPT plugin is and who approves them.
What are the honest limitations here?
Three things need saying plainly. A free audit is a snapshot, not monitoring. The visibility uplift figures quoted on vendor pages, including UD's own, are vendor-reported rather than independently audited. And AI answers vary between accounts, sessions and regions, so no tool measures a single objective truth.
The limitations that matter before you spend
--- A one-off audit does not replace monitoring. If your job requires a monthly trend line, a free scan will not do it.
--- UD's published figures of roughly 80% average visibility lift after AEO work and up to 3× conversion on AI-cited traffic are UD's own reported numbers, not third-party audited results. Treat them as directional.
--- AI answers are personalised and non-deterministic. The same prompt run twice can return different vendors, which is why every serious tool samples repeatedly rather than checking once.
--- Engine coverage on cheap tiers is narrower than the marketing implies. Otterly at US$29/mo puts Gemini behind a paid add-on, and most sub-US$99 tiers exclude Claude.
--- Fixing structure does not guarantee citation. Structure makes you readable. Citations still depend on authority signals that take 1 to 3 months to build.
So which should you buy?
Run the free audit this week and fix what it names. If after 60 days of shipped changes you still need to prove movement to someone who signs cheques, buy the cheapest tool that covers the engines your buyers actually use, which currently means Cairrot Pro at US$99/mo for five engines or HubSpot AEO at US$50/mo for three.
The sequence matters more than the tool. Diagnose, fix, then measure. Buying measurement before diagnosis is the most common way teams spend US$600 a year to watch a number they already knew.
Twenty-eight years of putting Hong Kong businesses online has taught us the same lesson repeatedly: the tool is never the hard part. Knowing which problem you are solving is.
We know AI's cold edges. We know your real challenges. 28 years with UD, turning technology into a partnership with warmth.
Reviewed by the UD AI team.
Start with the free scan, then decide
Get your AI visibility score and a prioritised action plan in under 30 seconds. Free, no credit card, no account. If you want help acting on the report, our AEO consultants will walk you through every step, from structure fixes to schema to the content that earns citations.
