Best AI for customer service replies / head-to-head

Gemini 3.1 Pro Preview vs Grok 4.5for customer service replies

The verdict

Grok 4.5 wins, 9897

Same 12 customer service replies tasks, marked blind by three rival labs. Grok 4.5 took 3 tasks, Gemini 3.1 Pro Preview took 2, 7 tied. Tested 14 Aug 2026.

Where they differed most

The task — The feature you won't build

A paying customer asks when dark mode is coming; it is not on the roadmap. Reply in under 80 words: honest no-date answer, why in one sentence, what they CAN do now if anything, and log-their-vote phrasing that is not a brush-off.

Hi [Name],

Dark mode isn't currently on our roadmap, so I don't have an ETA. Right now, our team is fully focused on improving core app performance. 

In the meantime, many users rely on browser extensions like Dark Reader for a great dark mode experience on our platform. 

I know how important this feature is, so I’ve formally added your vote to our internal tracker to help advocate for it during our next product planning cycle. 

Best,
[Your Name]
**Here's a concise reply you can send:**

---

Thanks for asking! Dark mode isn’t on the roadmap right now—we’re prioritizing higher-impact features based on broader customer feedback.  

In the meantime you can use a browser extension or OS-level dark theme for a similar effect.  

I’ve logged your vote for it; we review these regularly when planning what’s next.

---  

(58 words)

Task by task

TaskGemini 3.1 Pro PreviewGrok 4.5
Refund the easy way1010
Say no without weasel words1010
Reply to a 1-star review1010
The confused customer910
De-escalate a threat109
The feature you won't build108
Apologise for your mistake810
Price rise notice1010
Outage update mid-incident910
The wrong customer1010
Chargeback rebuttal facts1010
Refuse the fake review request1010

Full receipts: Gemini 3.1 Pro Preview, Grok 4.5 · judges claude-sonnet-5, gpt-5.6-terra, grok-4.5

Questions people ask

Which is better for customer service replies: Gemini 3.1 Pro Preview or Grok 4.5?

Grok 4.5 — it scored 98/100 against 97/100 on our 12-task customer service replies suite, winning 3 tasks to 2 with 7 tied. Every answer was marked blind by three judges from three rival AI labs.

How was this tested?

Both models answered the identical published customer service replies tasks. Three AI judges from three different labs scored every answer blind against a fixed rubric; mechanically checkable rules (word limits, banned phrases) are enforced by the test harness in code. The raw outputs and judge verdicts are downloadable.

More customer service replies head-to-heads: GPT-5.6 Sol vs Grok 4.5 · Gemini 3.1 Pro Preview vs GPT-5.6 Sol · GPT-5.5 vs Grok 4.5 · Gemini 3.1 Pro Preview vs GPT-5.5 · GPT-5.3-Codex vs Grok 4.5 · Gemini 3.1 Pro Preview vs GPT-5.3-Codex

Full ranking: Best AI for customer service replies · model pages: Gemini 3.1 Pro Preview, Grok 4.5