DeepSeek V4 Flash vs Qwen3.7 Max for customer service replies

The verdict

Effectively a dead heat: 9593

Same 12 customer service replies tasks, marked blind by three rival labs. Qwen3.7 Max took 2 tasks, DeepSeek V4 Flash took 1, 9 tied. Tested 14 Aug 2026.

Where they differed most

The task — The confused customer

A customer says the product is broken, but their description shows they have not plugged in the power lead ('the light never comes on and there is no cable in the wall socket'). Write a reply that fixes it without making them feel stupid. Under 90 words.

Thanks for letting me know about this. It sounds like the power lead might just need to be plugged into the wall socket. The unit won’t turn on or show any lights without that connection. Could you try plugging it in and see if the light comes on? Let me know how it goes—happy to help further if needed.
Hi there, I’m sorry it isn't turning on! Since the cable isn't in the wall socket yet, let's try that first. The device requires a direct wall connection to activate the light. 

Please plug the power lead firmly into the wall socket, and the light should turn right on. 

If it’s plugged in and still not working, just let me know and I’ll send a replacement right away!

Task by task

TaskDeepSeek V4 FlashQwen3.7 Max
Refund the easy way1010
Say no without weasel words1010
Reply to a 1-star review1010
The confused customer108
De-escalate a threat810
The feature you won't build88
Apologise for your mistake1010
Price rise notice810
Outage update mid-incident1010
The wrong customer1010
Chargeback rebuttal facts1010
Refuse the fake review request88

Full receipts: DeepSeek V4 Flash, Qwen3.7 Max · judges claude-sonnet-5, gemini-3.1-pro-preview, gpt-5.6-terra

Questions people ask

Which is better for customer service replies: DeepSeek V4 Flash or Qwen3.7 Max?

Effectively a dead heat: Qwen3.7 Max edged it 95/100 to 93/100 on our customer service replies suite — too close to matter, so 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 Qwen3.7 Max · DeepSeek V4 Flash vs GPT-5.6 Sol · GPT-5.5 vs Qwen3.7 Max · DeepSeek V4 Flash vs GPT-5.5 · Grok 4.5 vs Qwen3.7 Max · DeepSeek V4 Flash vs Grok 4.5

Full ranking: Best AI for customer service replies · model pages: DeepSeek V4 Flash, Qwen3.7 Max