Gemini · Customer support
Gemini for customer support
llmwise has 2 of Google's Gemini models, from Gemini 3.8 Flash (up to 250 messages a month on Pro) to Gemini 3.1 Pro (preview) (up to 125 messages a month). We ran the same customer support prompts on every one and published every reply: which Gemini model to use, from the results, what each costs per message, and how to get more out of it.
Based on 10 of our test runs on , through OpenRouter with the app's own prompt and settings. Updated .
Short answer
In our test runs on September 27, 2026, Gemini 3.1 Pro (5 of 5) passed the most customer support prompts: our pick for hard problems. For value, Gemini 3.8 Flash (4 of 5), 250 a month on Pro. It's also our pick for everyday.
Our picks for customer support
Hard problems
Passed 5 of 5 customer support prompts, both hard ones.
Best value
Passed 4 of 5 customer support prompts, with 250 a month on Pro.
Everyday
Passed 4 of 5 customer support prompts, at 250 a month on Pro. The same model as best value.
These picks aren't our opinion: they're what the results below give, by these rules, among the Gemini models in llmwise. They change when the results do.
- Hard problems: the model that passed the most prompts and, of those, the most hard ones. Models level on both share the pick: the prompts don't tell them apart, so we don't break the tie by price or by name.
- Best value: among the models that draw on the monthly allowance, the one with the most messages on Pro that passed no more than one prompt fewer than the top model. Ties go to the one that passed more, then to the lower cost per reply.
- Everyday: among the cheapest models on the page (the everyday models, which come from the daily count, when the page has any), the one that passed the most. Ties go to the one that passed more of the hard prompts, then to the lower cost per reply.
Our customer support test runs, model by model
How each model did on our 5 customer support prompts, what each reply counted as on Pro, and what it cost to run.
| Model | Passed | Hard ones | Messages used on Pro | Cost per reply | Time per reply |
|---|---|---|---|---|---|
| Gemini 3.1 Pro (preview)Google | 5 of 5 | 2 of 2 | 1 each, of 125 a month on Pro | $0.0106 | 8.7 s |
| Gemini 3.8 FlashGoogle | 4 of 5 | 2 of 2 | 1 each, of 250 a month on Pro | $0.0016 | 4.6 s |
One prompt, side by side
Each model's reply to “A refund request outside the window”, as it came, with whether it passed and what it cost.
The prompt: A refund request outside the window (hard)
Northwind Outfitters support policy - Returns: within 30 days of delivery, unworn items with tags get a full refund to the original payment method. - After 30 days and up to 60 days: exchange or a store gift card only, no refund. - Refunds are paid within 5 business days of the return reaching our warehouse. - Standard delivery takes 3 to 5 business days. If an order is more than 7 business days late, the customer gets free express shipping on their next order. - Staff can't give discount codes worth more than 15%. Customer message: "I bought a coat 45 days ago and never wore it. I'd like a refund to my card, please." Write the reply to the customer, following the policy. At most 150 words, signed "Sam, Northwind support".
Gemini 3.1 Pro
Passed: Graded 4.7 of 5 on average (lowest 4).
Hi there, Thank you for reaching out about returning your coat. Because your purchase was made 45 days ago, it falls outside our 30-day window for refunds to the original payment method. However, since your item is unworn and still within our 60-day return period, I would be happy to help you with an exchange or issue a Northwind Outfitters store gift card for the full amount. Please let me know which of these two options you prefer, and I will send you the return instructions. Best regards, Sam, Northwind support
551 tokens in, 763 out (640 of them reasoning) · 7.4 s · $0.0103 · 1 message on Pro · answered by google/gemini-3.1-pro-preview via Google ·
Gemini 3.8 Flash
Passed: Graded 4.3 of 5 on average (lowest 4).
Hi there, Thank you for reaching out to Northwind Outfitters. Under our policy, refunds to the original payment method are only available within 30 days of delivery. Because your purchase was 45 days ago, we are unable to issue a refund to your card. However, since you are within our 60-day window, we would be happy to offer you an exchange or a store gift card, provided the coat is unworn with the tags still attached. Please let us know whether you would prefer an exchange or a gift card, and we will send you the return instructions right away. Best regards, Sam, Northwind support
551 tokens in, 652 out (515 of them reasoning) · 5.9 s · $0.0029 · 1 message on Pro · answered by google/gemini-3.8-flash via Google ·
The customer support prompts, and how they're scored
Rubric (graded). The grader model scores the reply from 1 to 5 on each published criterion. It passes with an average of 4 or more and no criterion under 3, and only if it also meets the prompt's automatic rules (length, words it must or mustn't use).
The grader is Claude Opus 5.5 at low reasoning effort; its own replies are graded by GPT-6 Astra, so no model grades itself. Its prompt and every rubric are on the methods page.
Each prompt was sent the way llmwise sends a message in a side-by-side comparison, which offers no tools: the app's own system prompt, the model's own settings, and Pro's reply size limit (8,000 tokens). Read all five customer support prompts and how every reply was scored.
Prompts like these to try yourself
Gemini in llmwise
| Model | On Pro | On Free | Context window | Images | PDFs | Reasoning | API price per 1M, in / out |
|---|---|---|---|---|---|---|---|
| Gemini 3.1 Pro (preview)Google | 125/mo on Pro | Yes | 1.05M tokens | Yes | Whole file | Yes | $2.00 / $12.00 |
| Gemini 3.8 FlashGoogle | 250/mo on Pro | Yes | 1.05M tokens | Yes | Whole file | Yes | $0.75 / $3.75 |
Every limit is published. Paid plans also have a monthly fair-use limit on AI cost: Pro $7.50, Max $20, Ultra $42, Studio $85. Using every message on your plan at typical sizes stays under it; very large messages and heavy research use it faster. Every limit, explained.
What matters for customer support
Tone
Support replies need to sound calm and human, and match your brand. Give the model examples of replies you like.
Accuracy about your product
A model only knows your product if you tell it. Paste the policy or attach the help article, and ask it to stick to them.
Cost at volume
Support is high volume. A fast, low-cost model handles most drafts; a stronger one is worth it for the tricky few.
Languages
Customers write in many languages. Most models can draft replies in the customer's language; check anything important with a native speaker.
Gemini for customer support in llmwise
A persona for your team's voice
Create a persona with your tone, policies and sign-off, and a default model. Every chat started with it follows the same instructions.
Answers from your own docs
Attach your help-center pages or policy PDFs (up to 100 pages each) so replies follow what your product actually does.
Everyday models for volume
Everyday models don't touch the monthly allowance: a paid plan has 60 to 200 a day. Save the bigger models for the hard replies.
Switch models mid-chat
Start on a cheaper model; if the answer isn't good enough, switch models in the same chat. The next model sees the whole conversation, so you don't paste anything twice.
In llmwise, a message to Gemini goes to its maker, Google, or through OpenRouter when llmwise can't reach the maker directly. See the Privacy Policy.
Tips
Paste the customer's message and the relevant policy together.
Ask for a draft and a shorter version, then pick.
Ask the model to flag anything it isn't sure is true about your product.
Summarize a long thread before replying, so nothing gets missed.
Questions
Is Gemini good for customer support?
In our test runs on September 27, 2026, Gemini 3.1 Pro (preview) passed 5 of 5, Gemini 3.8 Flash passed 4 of 5 of our customer support prompts, against a best result of 5 of 5 among all 19 models. Every reply is published on this page and the methods page, so you can judge them yourself.
Which Gemini model should I use for customer support?
Start with Gemini 3.8 Flash for most replies, summaries of long threads, and turning notes into a macro, and move up to Gemini 3.1 Pro (preview) for most replies, summaries of long threads, and turning notes into a macro.
Can I use Gemini for customer support for free?
Yes: Gemini 3.1 Pro (preview) and Gemini 3.8 Flash are on the Free plan (a one-time trial of 5 messages).
Can llmwise answer my customers automatically?
No. llmwise is a chat app for people. It helps an agent draft, summarize and translate replies, but it doesn't connect to a help desk or answer customers on its own.
Claude, GPT, Gemini, DeepSeek, Grok, Kimi, GLM, and Mistral, in one chat.
See what a message costs before you send it. Free is 5 messages to try; sign in with an email link, no password or card.