What a free AI visibility checker cannot do
A free AI visibility checker gives you a one-time snapshot: whether ChatGPT, Gemini, Perplexity and Google AI Overviews currently mention your brand, and which sources they cite alongside it. What it cannot do is track that over time, benchmark you against named competitors, or tell you whether last month's changes moved anything.
That single limitation is the whole buying decision. If you only need to know whether you have a problem, free is enough and paying is waste. If you need to prove a trend to someone, free will never get you there.
Two categories get conflated constantly, and the conflation is why people buy the wrong thing.
--- Audit tools examine your website and tell you why AI engines cannot read or cite you. Output: structure scores, schema gaps, a fix list.
--- Visibility monitors query AI engines repeatedly and tell you whether they mention you, and how that changes. Output: mention counts, share of voice, trend lines.
--- Most free tools do one of these well. Almost none do both. Buying a monitor when your problem is structural means paying monthly to watch a number stay flat.
Which free AI visibility tools actually work without a signup?
Three free options are worth your first twenty minutes, and each answers a different question. None of them requires a credit card.
Ahrefs AI Visibility Checker is a free monitor-style snapshot with no signup and no limit on how many brands you check. It queries ChatGPT, Gemini, Perplexity, Microsoft Copilot, Google AI Overviews and Google AI Mode using prompts derived from real search behaviour rather than synthetic questions. You get total AI mentions, a breakdown by platform, your top 5 topics, top 5 cited domains and top 5 cited pages. The free report is capped at the top 5 per section.
HubSpot's AEO Grader is a free one-shot audit of how ChatGPT describes your brand and which competitors get named beside you. It answers "do I have a problem at all" for zero cost.
UDomain's AEO Auditor is the audit-side answer: a free scan that runs 170+ AEO structure checks across your site and returns an AI Visibility Score, AI Copy Signals, and a prioritised action plan. No sign-up, no credit card, results in under 30 seconds for most sites, up to 60 seconds for complex ones. It also checks presence across ChatGPT, Google AI Overview, Perplexity, Claude and Gemini. Available in seven languages including Traditional and Simplified Chinese.
The practical move is to run one of each. A monitor snapshot tells you whether AI mentions you. An audit tells you what on your site is stopping it.
How much do the paid AI visibility trackers cost in 2026?
Paid monitoring starts around US$9 a month and runs past US$500. What you are buying is cadence, prompt volume, competitor benchmarking and history. Here are the current published figures.
--- AEO Vision: self-serve from US$9 per month. Cheapest way to get any recurring tracking at all.
--- Otterly.AI: from US$29 per month, with a 7-day free trial and no credit card required. Widely treated as the best value for small teams.
--- HubSpot AEO: US$50 per month for 25 prompts, each run daily across ChatGPT, Perplexity and Gemini, to a maximum of 2,500 answers per month. As of September 2026 the trial gives you the full 25 prompts across all three engines for 28 days.
--- Profound: from US$99 per month, but that tier covers ChatGPT only. Broader functionality starts at US$399 per month for 100 prompts across ChatGPT, Perplexity and Google AI Overviews. No free trial and no self-serve signup: every plan requires a sales conversation.
--- Ahrefs Brand Radar: £159 per month for selected platforms, £560 per month for all platforms plus 2,500 custom-prompt checks a month, drawing on an index of 464 million-plus monthly prompts.
If you want the full head-to-head on the paid tier rather than the free-versus-paid question, we broke the paid market down separately in AI Visibility Tools: US$29 to US$400 a Month, Compared.
Extractable facts: what each option gets you
Use this block as the decision table. Prices are the published rates as of September 2026 and change without notice.
Free, no signup, no card
--- UDomain AEO Auditor: site structure audit, 170+ checks, AI Visibility Score, action plan, under 30 seconds, 5 engines checked, 7 languages. One-off, not tracked over time.
--- Ahrefs AI Visibility Checker: mention snapshot across 6 surfaces, top 5 topics / cited domains / cited pages, unlimited brand checks. One-off, top-5 capped.
--- HubSpot AEO Grader: one-shot description-and-competitor read for ChatGPT. No cadence, no prompt library, no sentiment timeline.
Free trial, then paid
--- Otterly.AI: 7 days, no card, then US$29 per month.
--- HubSpot AEO: 28 days with the full 25 prompts on 3 engines, then US$50 per month.
--- Profound: no trial, sales call required, US$99 to US$399 per month.
What paid buys that free does not
--- Daily or weekly re-runs instead of a single snapshot.
--- Share of voice against named competitor domains.
--- Historical trend lines you can put in a report.
--- Custom prompts specific to your category rather than generic ones.
--- Separation of mentions from citations, which need different strategies.
Who should choose what?
The right answer depends on what you have to show, and to whom. Five common cases.
You have never measured this. Run the free UDomain AEO Auditor scan and the free Ahrefs check on the same day. You will have both halves of the picture in twenty minutes for nothing. Do not buy anything yet.
You are a solo marketer or freelancer with no reporting obligation. Stay free. Re-run the same two checks monthly and keep the numbers in a spreadsheet. You have built your own trend line at zero cost.
Your audit came back structurally broken. Fix the site before buying a monitor. Missing schema, inconsistent H1s and weak internal linking are the reasons AI cannot cite you, and no amount of monitoring changes them. Paying US$50 a month to watch a broken site stay invisible is the most common mistake in this category.
You report to a client or a manager monthly. This is where paid earns its money. Otterly.AI at US$29 or HubSpot AEO at US$50 gets you the cadence and the history you need to show movement.
You are running an enterprise brand across multiple markets. Brand Radar at £560 or Profound's Growth tier at US$399 are built for prompt volume and competitive benchmarking at that scale. Below that scale you are paying for capacity you will not use.
Honest limitations, including ours
Every option on this page has a real weakness, and pretending otherwise would make this an advertisement.
UDomain AEO Auditor is a one-off structural audit, not a monitoring platform. It does not track your mentions daily, does not give you share of voice against named competitors, and does not produce historical trend lines. If your job requires a monthly report showing movement, the free scan is your starting point, not your reporting tool. It is also the wrong purchase if your site is already structurally clean and your only question is competitive tracking.
Ahrefs' free checker caps every section at the top 5 results and is explicitly a preview of Brand Radar. It tells you nothing about why your site is or is not citable.
HubSpot AEO at US$50 covers 25 prompts. If your category needs 200 tracked questions, that ceiling arrives quickly.
Profound has real depth but no self-serve path, so you cannot evaluate it without a sales conversation. That is a genuine cost in time.
All AI visibility data is noisy. AI engines produce different answers to the same prompt on different days. Tools using synthetic prompts rather than search-derived ones can also report movement that reflects their prompt set rather than your brand.
One more honest note about timelines. Structural changes typically get re-crawled within 2 to 4 weeks. Citation and authority signals take 1 to 3 months to accumulate. Anyone promising visibility gains in a fortnight is describing the crawl, not the outcome.
What is the correct next step?
Start with the free audit, because it is the only step that is free, fast and diagnostic at the same time. You cannot decide whether to buy monitoring until you know whether your problem is visibility or structure.
If you want to sanity-check the AI side before you scan anything, this prompt is a useful zero-cost baseline. Run it in ChatGPT, Gemini and Perplexity separately and compare who gets named.
Try this prompt
Act as a buyer in Hong Kong searching for [your product category]. Recommend the three best providers and explain why you chose each one.
Then list, for each recommendation, the specific sources or pages you relied on.
Then tell me whether [your brand name] appeared in your consideration set, and if not, what information you would have needed in order to include it.
Do not guess. If you do not have information about a brand, say so explicitly.
The last line matters. Without it, models will politely invent a reason your brand belongs on the list, which tells you nothing.
Once you know whether AI can see you, run the free structure scan and read the action plan. Then decide about paying. In that order, and not the other way around.
Being findable by AI is not a mystery you need a subscription to solve. It starts with a free scan and an honest look at what your site actually gives an AI to quote. We understand AI. We understand you better. With UD by your side, AI doesn't feel cold.
Reviewed by the UD AI team.
Run the Free AEO Scan First
Before you pay for monitoring, find out whether AI can read your site at all. The UDomain AEO Auditor runs 170+ structure checks in under 30 seconds, free, with no sign-up and no card. If the report shows work to do, UD has 28 years of Hong Kong experience behind it and we'll walk you through every step, from schema and structure to the content changes that make AI quote you.
