DeepSeek · Customer support
DeepSeek for customer support
llmwise has 2 of DeepSeek's models, from DeepSeek V4.1 Flash (up to 60 messages a day on Pro) to DeepSeek V4 Pro (up to 250 messages a month). We ran the same customer support prompts on every one and published every reply: which DeepSeek 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 October 8, 2026, DeepSeek V4 Pro (4 of 5) passed the most customer support prompts: our pick for hard problems. For everyday customer support, DeepSeek V4.1 Flash (4 of 5), from the daily count. It's also our pick for best value.
Our picks for customer support
Hard problems
Passed 4 of 5 customer support prompts, both hard ones.
Best value
Passed 4 of 5 customer support prompts, with 250 a month on Pro. The same model as hard problems.
Everyday
Passed 4 of 5 customer support prompts; an everyday model, so its messages come from the daily count (60 a day on Pro), not the monthly allowance.
These picks aren't our opinion: they're what the results below give, by these rules, among the DeepSeek 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 |
|---|---|---|---|---|---|
| DeepSeek V4 ProDeepSeek | 4 of 5 | 2 of 2 | 1 each, of 250 a month on Pro | $0.0015 | 4.8 s |
| DeepSeek V4.1 FlashDeepSeek | 4 of 5 | 1 of 2 | 1 each, of 60 a day on Pro | $0.0005 | 1.4 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".
DeepSeek V4 Pro
Passed: Graded 4.7 of 5 on average (lowest 4).
Hi there, Thanks for reaching out. Since your coat was purchased 45 days ago, it falls outside our 30-day refund window, so I'm unable to issue a refund to your original payment method. However, because you're still within 60 days of delivery, we can offer either an exchange or a store gift card for the item's value — as long as it's unworn with tags attached. If you'd like to go ahead with either option, just let me know which you prefer and I'll help get it sorted. Best, Sam, Northwind support
525 tokens in, 264 out (147 of them reasoning) · 2.5 s · $0.0012 · 1 message on Pro · answered by deepseek/deepseek-v4-pro-0813 via Wafer ·
DeepSeek V4.1 Flash
Passed: Graded 4.3 of 5 on average (lowest 3).
Hi there, Thanks for reaching out, and I'm sorry the coat didn't work out. Because your order was delivered 45 days ago, it falls outside our 30-day refund window. Under our policy, returns between 30 and 60 days are eligible for an exchange or a store gift card — we're not able to issue a refund to your original payment method at this stage. The good news: since the coat is unworn with tags still attached, you're well within the 60-day limit. If you'd like, I can set you up with either an exchange or a gift card for the full value — just let me know which you'd prefer. To get started, send the coat back to our warehouse and reply here with the tracking number. Once you tell me your choice, I'll process it as soon as the return arrives. Happy to help however I can. Sam, Northwind support
553 tokens in, 215 out (28 of them reasoning) · 1.1 s · $0.0003 · 1 message on Pro · answered by deepseek/deepseek-v4.1-flash via Together ·
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
DeepSeek in llmwise
| Model | On Pro | On Free | Context window | Images | PDFs | Reasoning | API price per 1M, in / out |
|---|---|---|---|---|---|---|---|
| DeepSeek V4 ProDeepSeek | 250/mo on Pro | Yes | 1.05M tokens | No | Text only | Yes | $0.40 / $4.00 |
| DeepSeek V4.1 FlashDeepSeek | 60/day on Pro | Yes | 1.05M tokens | Yes | Text only | Yes | $0.30 / $1.20 |
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.
DeepSeek V4 Pro and DeepSeek V4.1 Flash get a PDF's text rather than the whole file.
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.
DeepSeek 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.
DeepSeek models are served only through OpenRouter, by endpoints that don't store or train on prompts. 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 DeepSeek good for customer support?
In our test runs on October 8, 2026, DeepSeek V4 Pro passed 4 of 5, DeepSeek V4.1 Flash passed 4 of 5 of our customer support prompts, against a best result of 4 of 5 among all 19 models. Every reply is published on this page and the methods page, so you can judge them yourself.
Which DeepSeek model should I use for customer support?
Start with DeepSeek V4.1 Flash for quick rewrites, short translations and tagging a message by topic, and move up to DeepSeek V4 Pro for most replies, summaries of long threads, and turning notes into a macro.
Can I use DeepSeek for customer support for free?
Yes: DeepSeek V4 Pro and DeepSeek V4.1 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.