We asked two GEO tools the same five questions about the same website on the same day. Both said the site was invisible to AI. They disagreed on almost everything else: how many engines to check, how many prompts you need, and what happens when the trial ends.
Why We Ran Two GEO Tools on the Same Prompts
Generative engine optimization (GEO) is the work of getting your pages cited in AI answers. The research paper that named it reports that “GEO can boost visibility by up to 40% in generative engine responses” (Aggarwal et al., arXiv, 2024). GEO tools exist to measure that visibility, so you can tell whether anything you change actually moves it.
Most “best GEO tools” lists describe features from the vendors’ websites. We wanted something simpler: the same input in two tools, and a record of what came out. For the wider category, including SEO suites with AI features, see our roundup of AI SEO tools we tested.
So we picked Otterly.AI and Writesonic’s AI Search Tracking. Both offer a 7-day trial without a card. Both track a website across several AI engines. That made them a fair pair.
What did we track? A small marketing website that our own team runs. It’s a real site with real content, but it’s small, which turned out to matter.
Key Takeaways
In our October 2026 test, Otterly.AI counted 244 citations across four AI engines for the same 5 prompts. Both tools agreed our site was invisible to AI; they differed on engines covered, prompt minimums and trial terms.
Quick Verdict: Otterly.AI or Writesonic?
Otterly.AI gave us more data per prompt: it covered four AI engines and counted every citation, while Writesonic’s Starter trial covered three engines. Writesonic was easier to set up with exactly the prompts we wanted.
| If you want… | Pick | Why, from our test |
|---|---|---|
| The most AI engines in the base plan | Otterly.AI | ChatGPT, Google AI Overview, Perplexity and Microsoft Copilot included |
| To track only your own handful of prompts | Writesonic | No minimum; we tracked exactly 5 |
| A low monthly entry price | Otterly.AI | Lite at $29/month for 15 tracked prompts |
| Share-of-voice style reporting | Writesonic | Reports AI visibility, share of voice and citation share |
| Clear trial wording | Otterly.AI | Billing said “Trial ends in 7 days”; Writesonic’s banner talked about an automatic upgrade |
Which matters more to you, coverage or control? That’s the real choice between these two GEO tools.
How We Tested Two GEO Tools With the Same 5 Prompts
We tested both tools on October 21, 2026, with one work account, Google sign-in and no card, tracking the same website with the market set to United States and English. We chose the five prompts before opening either tool:
- What are the best AI SEO agencies in Taiwan?
- How can I get my website cited by ChatGPT?
- What is generative engine optimization (GEO)?
- What are the best tools to track AI search visibility?
- How do I optimize content for Google AI Overviews?
Why these five? They’re the questions our own audience asks, and they range from a definition to a local buying question. The first one is about our own market, which is why it names Taiwan.
We recorded every screen, copied numbers word for word, and kept masked screenshots. We didn’t press any button that would change billing, and we didn’t wait for more than one day of data. Keep that in mind: this is a first-day comparison, not a trend.
Otterly.AI: Four Engines Included, 15-Prompt Minimum to Start
Otterly.AI’s base product checked four engines for every prompt: ChatGPT, Google AI Overview, Perplexity and Microsoft Copilot. All four returned answers for all five of our prompts, and three more engines (Google AI Mode, Gemini and Claude) were offered as paid add-ons.
Setting up Otterly.AI
Sign-up with Google asked only for profile and email. Onboarding asked whether we were an agency or a brand, then for the website, country and language.
Two things surprised us. First, Otterly replaced the brand name we typed with one it generated from the domain. Second, it suggested competitors on its own: Semrush, Ahrefs, Surfer, Moz, HubSpot, Yext, MarketMuse and Frase. For a small site, that’s an ambitious peer group.
Then came the prompt step. The page said it “recommends” 15 prompts, but the Next button stayed disabled at 5 and at 14. It turned on at exactly 15. We kept our five and added the first ten suggestions to get through. If you only care about a few questions, you’ll be tracking extra ones anyway.
Waiting for the first report
The first report took several minutes. Until then, pages said “We are still preparing this report” and “Today’s data is still processing.” An interactive demo window then covered the report with no close button; reloading the page cleared it.
What did the report say? Brand coverage 0% on every prompt. Our domain was cited 0 times. That’s an honest result for a small site, and exactly what a GEO tool should tell you before you spend money on fixes.
Writesonic: No Prompt Minimum, Trial of a Named Paid Plan
Writesonic let us track exactly our 5 prompts, with no minimum, and its first report analyzed 5 answers across 3 AI platforms. The platforms on our Starter trial were ChatGPT, Gemini and Google AI Overviews.
Setting up Writesonic
The sign-up page promised: “Sign Up for Free. No Credit Card Required.” Google sign-in asked for name, profile picture and email. Writesonic then picked five topics for us and pre-selected 24 suggested prompts. We cleared them all and added our five by hand, which meant opening each topic in turn.
It also suggested ten competitors and pre-selected five of them. While it worked, the screen read “Running your prompts… Querying ChatGPT, Claude, Gemini, and more…”
What the first report showed
The first report said it was “Created by analysing 5 answers across 3 AI platforms and 5 prompts.” AI visibility was 0% (0 of 5 answers), share of voice 0% (rank 6 of 6) and citation share 0%. The dashboard later showed 15 answers, all at 0% visibility.
Here’s the catch, though. Can you keep using it for free? No. To get past that first report, we had to pick a plan and press “Start free trial.” Writesonic doesn’t have a free tier for GEO tracking. It has a trial of a named paid plan, and the banner said: “Once the trial ends, you’ll automatically be upgraded to your Starter plan.”
We opened billing to check. It showed “Payment method: No card added.” We’d rather a trial said that on the first screen, next to the upgrade banner.
Writesonic also launched a 13-minute product tour after onboarding. “Skip anyway” gets you out.
Same Prompts, Different Engines: Otterly’s Citation Counts
ChatGPT produced 130 of the 244 citations Otterly counted across our five prompts, about 53%, while Microsoft Copilot produced 28. Here are the full counts, prompt by prompt.
| Prompt | ChatGPT | Google AI Overview | Perplexity | Microsoft Copilot | Total |
|---|---|---|---|---|---|
| What is GEO? | 37 | 9 | 10 | 5 | 61 |
| How to get cited by ChatGPT | 22 | 11 | 10 | 5 | 48 |
| Best tools to track AI visibility | 29 | 7 | 10 | 5 | 51 |
| Optimizing for AI Overviews | 17 | 7 | 10 | 5 | 39 |
| Best AI SEO agencies in Taiwan | 25 | 2 | 10 | 8 | 45 |
| All five prompts | 130 | 36 | 50 | 28 | 244 |
Two patterns stand out. Perplexity cited exactly 10 sources on every prompt, which looks like a fixed limit. And Google AI Overview cited only 2 sources for the Taiwan agencies question, the fewest of any engine on any prompt.
Why does this matter for choosing GEO tools? Because a tool that checks only ChatGPT sees about half the citation picture, at least on our prompts. Writesonic’s Starter trial didn’t include Perplexity or Copilot, so those 78 citations were outside its view.
Who Gets Cited in AI Answers: What Both Tools Showed
Both tools listed Google’s own guide to optimizing for generative AI among the cited pages, and Otterly ranked it first, counting it 7 times across our prompts. That guide says Google’s generative AI features “are rooted in our core Search ranking and quality systems” (Google Search Central).
Writesonic’s citation list also included Google’s “Succeeding in AI search” post, a Reddit r/SEO thread, a YouTube video, Medium, and several SEO software and agency sites. None of them was our site.
So what’s the lesson from that list? AI answers about GEO lean on official documentation, community threads and established tool vendors. A small site has to earn its way into that company. Google’s guide puts it plainly: “Creating content that people find unique, compelling, and useful will likely influence your website’s presence.”
If you also track classic rankings, Semrush’s Position Tracking now offers ChatGPT and Gemini as search engines; we covered that setup in our Semrush keyword research review.
Pricing and Trials Side by Side
Otterly.AI’s cheapest plan was Lite at $29/month for 15 tracked prompts, while Writesonic’s Starter was $79/month billed annually for 50 prompts, shown in billing as $948.00 per year. Both started with a 7-day trial and no card.
| Otterly.AI | Writesonic AI Search Tracking | |
|---|---|---|
| Free plan | None; 7-day trial, no card | None; 7-day trial of a paid plan, no card |
| Entry plan | Lite: $29/month, 15 prompts | Starter: $79/month billed annually, 50 prompts, 1 project |
| Next tiers | Standard $189 (100 prompts), Premium $489 (400 prompts) | Basic $199 (100 prompts), Growth $399 (200 prompts, 2 projects) |
| Engines in our test | ChatGPT, Google AI Overview, Perplexity, Microsoft Copilot | ChatGPT, Gemini, Google AI Overviews |
| Prompt minimum at setup | 15 | None |
| Trial allowance | 50 prompts, 100 GEO audits | 50 prompts |
| Tracking frequency | Paid plans list “Daily AI visibility tracking” | Charts labeled “Daily,” with a next-run countdown |
Which one costs less? It depends on how you read the price tags. Otterly’s prices are monthly. Writesonic’s $79 is the monthly equivalent of an annual bill.
Which GEO Tool Fits Which Team
Pick Otterly.AI if you want the widest engine coverage we saw (four engines) and the lowest entry price ($29/month). Pick Writesonic if you want to track exactly your own prompts and you like share-of-voice reporting.
Still undecided? Some quick matches:
- Solo creators and small sites: Otterly.AI’s Lite plan is the cheaper way in, but budget for the 15-prompt minimum.
- Marketing teams with a short, fixed question list: Writesonic lets you track only those questions.
- Anyone reporting to a boss or client: Writesonic’s share-of-voice view is easier to put in a slide.
Whatever you choose, run your own five prompts before you pay. Our site scored 0% in both tools on day one. That’s not a failure of the tools; it’s the starting line they’re built to measure.
Would you rather hand the fixing to someone else? Our guide to comparing generative engine optimization services lists what to check before you hire a GEO agency.