Why Four AI Platforms Give Four Different Answers About the Same Law Firm
Most law firms think about “AI visibility” as a single scoreboard. Either the AI recommends you or it does not. That assumption is costing them, because it is wrong.
When we built the PI AI Visibility Index, we asked four AI platforms (ChatGPT, Gemini, Perplexity, and Grok) the ten questions injured people actually ask when they need a lawyer, across seven of the largest legal markets in the country. One finding cut through everything else: the same firm, answering the same question, can be a star on one platform and completely absent on another. AI search is not one game. It is four, and each one rewards a different set of signals.
One firm, four verdicts
In one market we studied, a trial boutique put up a result that looked impossible on paper. Across ten discovery questions and four platforms, here is how often it was named:
- Gemini named it in 8 of 10 answers.
- ChatGPT named it in 7 of 10.
- Grok named it in 4 of 10.
- Perplexity named it in 0 of 10.
Same firm. Same questions. A near sweep on two engines and a shutout on a third. That spread is not noise or randomness. It is a direct reflection of how each platform is built and which signals it trusts.
What makes the case so clean is that this firm’s surface footprint is quiet. It has a small handful of Google reviews, the most recent from a couple of years ago. Its blog has not been updated since 2018. Its website is dated. By every metric a traditional marketing agency would put on a dashboard, this firm looks invisible. Yet two of the four platforms treated it as one of the most authoritative names in its market.
Two kinds of signals
To understand why, it helps to know that these four platforms are not built the same way. They sit at different points on a spectrum between two sources of truth.
Live-web signals come from what an engine can read on the internet at the moment you ask. Current reviews, an active and complete Google Business Profile, presence in directories, recently updated content, and inclusion in “best of” listicles. Perplexity sits at this end of the spectrum by design. It runs a fresh search on almost every query and cites the sources it pulls, so its answers closely mirror whatever the live web is saying right now. Grok also leans toward real-time signals, drawing on current web and social activity.
Entity-authority signals are different. These live inside the model itself, built up from everything it absorbed during training and reinforced by a knowledge graph. Verifiable results, a consistent identity across the web, earned media, and citations from authoritative sources all feed this. When a name has been associated with meaningful outcomes and serious coverage for years, the model “knows” that firm the way you know a landmark, without having to look it up. ChatGPT draws heavily on this deep trained knowledge, and Gemini is wired directly into Google’s Knowledge Graph, which is one of the largest structured maps of entities and their reputations in existence.
Now the impossible result makes sense. Perplexity scored the boutique at zero because it was doing exactly what it is designed to do: reflect the live web. It read current reviews, directories, and fresh listicles, and on that surface the firm genuinely is quiet, so it did not surface. ChatGPT and Gemini were not scoring the firm’s website at all. They were recalling an entity built from decades of documented results and national press. The reputation is baked into what those models already know. None of these engines is right or wrong here. They are answering different questions about the same firm.
There was even a giveaway that Gemini and ChatGPT were recalling rather than researching: they could not agree on the firm’s web address, and one confidently cited a domain the firm does not even own. They knew who the firm was while guessing at the URL. That only happens when the knowledge is coming from inside the model, not from a page it just fetched.
Why this matters for your firm
If AI visibility were one game, you could win it with one strategy. Because it is four, a single strength leaves you exposed everywhere else.
Consider two firms that are mirror images of each other. The first has hundreds of glowing reviews and a busy blog but a thin record and almost no earned media. It will do well on Perplexity and vanish on Gemini and ChatGPT. The second has a wall of verifiable results and press but a neglected profile and stale content. It will be recalled by ChatGPT and Gemini and skipped by Perplexity. Each firm is winning one game and losing the other, and most of them have no idea which is which.
This is the trap in chasing a single number. A firm that pours everything into review generation may still be invisible to the platforms that decide based on authority. A firm resting on a distinguished reputation may be missing from the engines that read today’s web. The signals that build lasting AI visibility are not interchangeable, and neither are the platforms.
What actually moves the needle
The firms that win across all four platforms are the ones that build both signal classes deliberately.
On the live-web side, that means keeping your Google Business Profile complete and active, earning current reviews, maintaining consistent name, address, and phone information everywhere you appear, and publishing content that directly answers the questions your future clients ask. This is the faster-moving layer, and it is where answer engine optimization overlaps with the fundamentals of SEO.
On the entity-authority side, the work is slower but far stickier. Document your results in a form machines can verify. Build earned media and citations from sources the models already trust. Present one consistent identity across the web so the AI is not splitting your reputation across name variants. This is the layer that made a boutique with 13 reviews outperform firms spending millions on television, and it is the part almost no one is building on purpose.
The point is not to pick a lane. It is to recognize that you are being scored in four different ways at once, and to build for all of them. That is the difference between a firm that shows up sometimes and one the AI reaches for every time.
Here is what most firms get wrong: they optimize for the one platform they happen to check, then assume the rest look the same. They do not. Right now, across ChatGPT, Gemini, Perplexity, and Grok, your firm has four different scores, and you almost certainly do not know what they are.
We do this for a living. We measure your firm on all four platforms, pinpoint exactly which of the two signal classes is holding you back, and build the entity authority and live-web presence that make the AI reach for your name instead of a competitor’s. This is the entire focus of our answer engine optimization for law firms.
The AI in your market has already decided who it trusts. If that name is not yours, every day you wait is another day it recommends someone else. Get your firm’s AI visibility scores and let’s fix what the numbers reveal.