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

Gemini 3.1 Pro Preview vs GPT-5.6 Terrafor customer service replies

The verdict

Dead heat: 97 each

Same 12 customer service replies tasks, marked blind by three rival labs. Tested 14 Aug 2026.

Where they differed most

The task — Outage update mid-incident

Write a status update 90 minutes into an outage with no fix yet. Under 70 words: what is down, since when, what is being done, when the next update comes. No 'we take this seriously', no cause speculation.

Core platform services have been unavailable for the past 90 minutes. Our engineering team is actively investigating the issue and working to restore access. There is currently no estimated time for a resolution. 

We will provide the next update in 30 minutes.
**Status Update:**  
Service remains unavailable since [time]. Our engineering team is actively investigating and working to restore service. No fix is available yet. We will provide the next update by [time, 30 minutes from now].

Task by task

TaskGemini 3.1 Pro PreviewGPT-5.6 Terra
Refund the easy way1010
Say no without weasel words1010
Reply to a 1-star review1010
The confused customer910
De-escalate a threat1010
The feature you won't build1010
Apologise for your mistake810
Price rise notice1010
Outage update mid-incident96
The wrong customer1010
Chargeback rebuttal facts1010
Refuse the fake review request1010

Full receipts: Gemini 3.1 Pro Preview, GPT-5.6 Terra · 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 GPT-5.6 Terra?

They tied at 97/100 on our customer service replies suite — for this job, pick on price or the product you already use.

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 GPT-5.6 Terra · Gemini 3.1 Pro Preview vs GPT-5.6 Sol · GPT-5.5 vs GPT-5.6 Terra · Gemini 3.1 Pro Preview vs GPT-5.5 · GPT-5.3-Codex vs GPT-5.6 Terra · 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, GPT-5.6 Terra