Compare / Qwen3.5-27B vs DeepSeek-V3.1-Terminus

Qwen3.5-27B vs DeepSeek-V3.1-Terminus

Which is cheaper, which is more capable, and which does better at each kind of work, from 15 results on 3 sources that measured both models.

AlibabaQwen3.5-27B Released 24 Feb 2026 · $0.27 in · $2.16 out
DeepSeekDeepSeek-V3.1-Terminus Released 22 Sep 2025 · $0.27 in · $1.00 out
Qwen3.5-27B wins 83 too close to callDeepSeek-V3.1-Terminus wins 4

Of the 15 results both models have, the better value on each. Results whose reported ranges overlap are too close to call.

Results as of 9 October 2026 (catalogue release 2026-10-09-dd620e778ac5). See also Alibaba vs DeepSeek, every model from both labs.

Qwen3.5-27B or DeepSeek-V3.1-Terminus? The short answer

Pick Qwen3.5-27B if quality matters most: it scores higher (Intelligence Index 22.9 against 14.8). Pick DeepSeek-V3.1-Terminus if cost matters more: it costs 39% less per token.

  • DeepSeek-V3.1-Terminus is cheaper: $0.45 against $0.74 per million tokens, 39% less.
  • Qwen3.5-27B scores higher on the Artificial Analysis Intelligence Index: 22.9 against 14.8.
  • Qwen3.5-27B is newer: released 24 Feb 2026, against 22 Sep 2025 for DeepSeek-V3.1-Terminus.
  • On third-party benchmarks, on the results both models have: Qwen3.5-27B does better for reasoning and knowledge; DeepSeek-V3.1-Terminus for writing.

Head to head

22.9
Intelligence Index
14.8
$0.74
Price per million tokens, blendedlower is better
$0.45
262,144
Context window, tokens
163,840

Every fact side by side

Qwen3.5-27BDeepSeek-V3.1-Terminus
Price per million tokens$0.27 in · $2.16 out$0.27 in · $1.00 out
Blended (3 in : 1 out)$0.74$0.45
Cheapest host, blended$0.54 (Alibaba)$0.45 (SiliconFlow, FP8)
Intelligence Index22.914.8
Spring Prompt overall––
Output speed, tokens a second––
Context window262,144 tokens163,840 tokens
Released24 Feb 2026 (newer)22 Sep 2025
WeightsOpenOpen
Developer based inChinaChina

Prices are the developer's list price where we have read it, otherwise the typical host on OpenRouter; see every model's price. Intelligence and speed from Artificial Analysis.

Which is better for what

Each model's rank among the models on sale today, for each kind of work, from our own benchmarks and licensed sources. Further right is better; the better rank is in green.

Agents and tool useMulti-step tasks with tools: support desks, coding agents, function calls 145 of 164 88 of 164
Reasoning and knowledgeHard questions across science, maths and general knowledge 82 of 198 109 of 198
WritingWhat people prefer in blind comparisons, and judged writing quality 98 of 188 81 of 188
Sticking to the factsSummarising without inventing things, and factual answers 121 of 152 not measured

Every shared result

Each model's best result on every measure both have, grouped by benchmark, with the setting that produced it. Under each measure, every model that benchmark has measured is a grey tick, best to the right, so you can see where the two sit in the field. The headline measures of each benchmark come first; the rest are under "Show all". Green marks the better value; where a source reports ranges that overlap, neither is marked.

MeasureQwen3.5-27BDeepSeek-V3.1-Terminus
Arena (formerly LMArena) reported by Arena (formerly LMArena) · 3 results
Overall · TextArena rating, higher is better 129 · 115 of 387 measured 1,409 1,417thinking reasoning
Business, management and finance · TextArena rating, higher is better 128 · 103 of 380 measured 1,408 1,423thinking reasoning
Creative writing · TextArena rating, higher is better 145 · 87 of 385 measured 1,358 1,405
Artificial Analysis reported by Artificial Analysis · 3 results
Artificial Analysis Intelligence Indexindex score, higher is better 86 · 129 of 243 measured 22.9 14.8thinking reasoning
GPQA Diamond% of questions, higher is better 74 · 112 of 231 measured 85.8% 79.2%thinking reasoning
Humanity's Last Exam% of questions, higher is better 95 · 121 of 242 measured 23.9% 16.4%thinking reasoning
UGI Leaderboard reported by UGI Leaderboard · 3 results
Writing score · UGIscore out of 100, higher is better 99 · 64 of 230 measured 42.4think-prefill reasoning 54.0thinking reasoning
Requested-length error · UGI% off the requested word count, lower is better 49 · 174 of 230 measured 11.0%think-prefill reasoning 32.0%thinking reasoning
Style adherence · UGIscore from 0 to 1, higher is better 147 · 43 of 230 measured 0.33no reasoning 0.37thinking reasoning
Show all 15 results (6 more)
MeasureQwen3.5-27BDeepSeek-V3.1-Terminus
Arena (formerly LMArena) reported by Arena (formerly LMArena) · 2 results
Instruction following · TextArena rating, higher is better 122 · 93 of 387 measured 1,401 1,420thinking reasoning
Writing, literature and language · TextArena rating, higher is better 135 · 88 of 386 measured 1,380 1,412thinking reasoning
Artificial Analysis reported by Artificial Analysis · 4 results
IFBench% of instructions, higher is better 24 · 86 of 195 measured 75.6% 57.0%thinking reasoning
Long-context reasoning (AA-LCR)% of questions, higher is better 63 · 113 of 233 measured 77.7% 69.3%thinking reasoning
Terminal-Bench Hard% of tasks, higher is better 61 · 63 of 190 measured 32.6% 31.8%no reasoning
τ²-bench telecom% of tasks, higher is better 28 · 118 of 193 measured 93.9% 37.1%no reasoning

Quick answers

Is Qwen3.5-27B better than DeepSeek-V3.1-Terminus?

Pick Qwen3.5-27B if quality matters most: it scores higher (Intelligence Index 22.9 against 14.8). Pick DeepSeek-V3.1-Terminus if cost matters more: it costs 39% less per token.

Which is cheaper, Qwen3.5-27B or DeepSeek-V3.1-Terminus?

DeepSeek-V3.1-Terminus is cheaper: $0.45 against $0.74 per million tokens, 39% less.

Which is better for agents and tool use, Qwen3.5-27B or DeepSeek-V3.1-Terminus?

DeepSeek-V3.1-Terminus ranks 88 of 164 models on sale for multi-step tasks with tools: support desks, coding agents, function calls, against 145 for Qwen3.5-27B.

Which is better for reasoning and knowledge, Qwen3.5-27B or DeepSeek-V3.1-Terminus?

Qwen3.5-27B ranks 82 of 198 models on sale for hard questions across science, maths and general knowledge, against 109 for DeepSeek-V3.1-Terminus.

Which is better for writing, Qwen3.5-27B or DeepSeek-V3.1-Terminus?

DeepSeek-V3.1-Terminus ranks 81 of 188 models on sale for what people prefer in blind comparisons, and judged writing quality, against 98 for Qwen3.5-27B.

Which has the bigger context window, Qwen3.5-27B or DeepSeek-V3.1-Terminus?

Qwen3.5-27B: 262,144 tokens, against 163,840 for DeepSeek-V3.1-Terminus.

Run Qwen3.5-27B and DeepSeek-V3.1-Terminus on your own prompt

Benchmarks aren't your data. Try both side by side in the playground, with the cost of every answer.

Try the playgroundTalk to us