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GPT-5.1 vs Qwen3.5 397B A17B

Updated October 21, 2026. 61 benchmarks have a result for both. Coding is ranked on the Vibe Coding Index; every other board is shown as published.

Replace GPT-5.1 Replace Qwen3.5 397B A17B
GPT-5.1OpenAI
Coding
53.3
Overall
24.7
Output $/M
$10.00
33
Qwen3.5 397B A17BQwen
Coding
28.6
Overall
21.4
Output $/M
$2.34
28
vs boards won of 61 shared

Decision reading

Pick GPT-5.1 for coding: it scores 53.3 on the Vibe Coding Index against 28.6 for Qwen3.5 397B A17B.

Pick Qwen3.5 397B A17B when output tokens cost 4.3x less, or when what matters is LMArena WebDev or LMArena Text: coding, where it leads.

Model AGPT-5.1OpenAI53.3/1002 independent benchmarks$1.02 per solved taskModel BQwen3.5 397B A17BQwen28.6/1001 independent benchmarkNo cost per solved task
Shared results
61
GPT-5.1 only
39
Qwen3.5 397B A17B only
4
Like-for-like categories
8 of 9

Shared results can support a head-to-head reading. Results only one model has describe coverage, not superiority.

Which one for your work

Each card is decided by one number both models carry. Where only one has it, the card says so and makes no call.

At a glance

Coding index
GPT-5.1 53.3 from 2 benchmarks, Qwen3.5 397B A17B 28.6 from 1 benchmark.
Widest category
Agentic work, 13.7 points apart on average over 1 shared benchmark.
Widest single gap
τ²-Bench Telecom: GPT-5.1 81.9% against Qwen3.5 397B A17B 95.6%, 13.7 points apart on a 0 to 100 scale.
Output price
GPT-5.1 $10.00 against Qwen3.5 397B A17B $2.34 per million output tokens, 4.3x apart.
Context window
GPT-5.1 takes 400K tokens, Qwen3.5 397B A17B 262K.

Benchmark by benchmark

First the score: boards each model leads, per category, where both have a result. Then every board, a category to a fold; bars are each result on a 0 to 100 scale, so compare the two in a row, not one row with another.

Boards won, where both have a result
CategoryGPT-5.1BarsQwen3.5 397B A17BTies
Coding15
Intelligence20
Agentic work01
Reasoning54
Math03
Knowledge31
Web design43
General1811
All shared boards3328
CodingLike-for-likeFour of these boards feed the Vibe Coding Index15
Coding benchmarks for GPT-5.1 and Qwen3.5 397B A17B
BenchmarkGPT-5.1Qwen3.5 397B A17BLeader
SWE-bench Verified66.0%Not measuredOnly GPT-5.1 measured
LMArena WebDev13961400Qwen3.5 397B A17B
AA Coding Index49.4Not measuredOnly GPT-5.1 measured
LiveCodeBench (Vals AI)86.5%Not measuredOnly GPT-5.1 measured
SWE-bench Verified (Vals AI)69.8%Not measuredOnly GPT-5.1 measured
Vibe Code Bench (Vals AI)24.6%Not measuredOnly GPT-5.1 measured
LiveCodeBench (Artificial Analysis run)86.8%Not measuredOnly GPT-5.1 measured
SciCodeNot measured44.8%Only Qwen3.5 397B A17B measured
Terminal-Bench Hard (Artificial Analysis run)45.5%40.9%GPT-5.1
Terminal-Bench47.6%Not measuredOnly GPT-5.1 measured
GSO-Bench13.7%Not measuredOnly GPT-5.1 measured
WeirdML60.8%Not measuredOnly GPT-5.1 measured
ALE-BenchNot measured621.9Only Qwen3.5 397B A17B measured
LMArena Text: coding14531464Qwen3.5 397B A17B
LMArena Text: software and IT14541463Qwen3.5 397B A17B
LMArena WebDev: React13071388Qwen3.5 397B A17B
LMArena WebDev: HTML14051410Qwen3.5 397B A17B
LMArena WebDev: from an image1421Not measuredOnly GPT-5.1 measured
Neither model has a result on the other 20 boards here
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index20
Intelligence benchmarks for GPT-5.1 and Qwen3.5 397B A17B
BenchmarkGPT-5.1Qwen3.5 397B A17BLeader
AA Intelligence Index24.721.4GPT-5.1
Epoch Capabilities Index149.8146.8GPT-5.1
Agentic workLike-for-likePublic boards, shown as published, kept out of the index01
Agentic work benchmarks for GPT-5.1 and Qwen3.5 397B A17B
BenchmarkGPT-5.1Qwen3.5 397B A17BLeader
τ²-Bench Telecom81.9%95.6%Qwen3.5 397B A17B
APEX-AgentsNot measured24.9%Only Qwen3.5 397B A17B measured
DeepResearch Bench42.8%Not measuredOnly GPT-5.1 measured
Vending-Bench 2$1,473Not measuredOnly GPT-5.1 measured
Neither model has a result on the other 35 boards here
ReasoningLike-for-likePublic boards, shown as published, kept out of the index54
Reasoning benchmarks for GPT-5.1 and Qwen3.5 397B A17B
BenchmarkGPT-5.1Qwen3.5 397B A17BLeader
GPQA Diamond86.6%Not measuredOnly GPT-5.1 measured
MMMU Pro (Vals AI)83.2%Not measuredOnly GPT-5.1 measured
GPQA Diamond (Artificial Analysis run)87.3%89.3%Qwen3.5 397B A17B
Humanity's Last Exam (Artificial Analysis run)28.5%29.0%Qwen3.5 397B A17B
GPQA Diamond (Epoch AI run)87.6%86.4%GPT-5.1
ARC-AGI72.8%Not measuredOnly GPT-5.1 measured
ARC-AGI-217.6%Not measuredOnly GPT-5.1 measured
SimpleBench53.2%Not measuredOnly GPT-5.1 measured
Chess puzzles42.0%Not measuredOnly GPT-5.1 measured
Mystery game puzzles19.0%18.0%GPT-5.1
VPCT58.7%Not measuredOnly GPT-5.1 measured
LMArena Text: hard prompts14571448GPT-5.1
LMArena Text: expert14701462GPT-5.1
LMArena Text: hard prompts in English14621450GPT-5.1
LMArena Vision: diagrams12641277Qwen3.5 397B A17B
LMArena Vision: homework12721292Qwen3.5 397B A17B
Neither model has a result on the other 5 boards here
MathLike-for-likePublic boards, shown as published, kept out of the index03
Math benchmarks for GPT-5.1 and Qwen3.5 397B A17B
BenchmarkGPT-5.1Qwen3.5 397B A17BLeader
AIME93.3%Not measuredOnly GPT-5.1 measured
MGSM (Vals AI)93.0%Not measuredOnly GPT-5.1 measured
AA Math Index94.0Not measuredOnly GPT-5.1 measured
AIME 2025 (Artificial Analysis run)94.0%Not measuredOnly GPT-5.1 measured
OTIS Mock AIME88.6%88.9%Qwen3.5 397B A17B
FrontierMath, tiers 1 to 3Not measured31.2%Only Qwen3.5 397B A17B measured
LMArena Text: math14461453Qwen3.5 397B A17B
LMArena Text: mathematical work14491454Qwen3.5 397B A17B
Neither model has a result on the other 5 boards here
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index31
Knowledge benchmarks for GPT-5.1 and Qwen3.5 397B A17B
BenchmarkGPT-5.1Qwen3.5 397B A17BLeader
MMLU Pro86.4%Not measuredOnly GPT-5.1 measured
LegalBench (Vals AI)85.7%Not measuredOnly GPT-5.1 measured
CaseLaw (Vals AI)73.4%Not measuredOnly GPT-5.1 measured
CorpFin (Vals AI)63.8%Not measuredOnly GPT-5.1 measured
TaxEval (Vals AI)74.9%Not measuredOnly GPT-5.1 measured
MortgageTax (Vals AI)61.4%Not measuredOnly GPT-5.1 measured
MedQA (Vals AI)96.4%Not measuredOnly GPT-5.1 measured
MedCode (Vals AI)52.7%Not measuredOnly GPT-5.1 measured
MMLU Pro (Artificial Analysis run)87.0%Not measuredOnly GPT-5.1 measured
SimpleQA Verified48.0%Not measuredOnly GPT-5.1 measured
LMArena Text: science14591457GPT-5.1
LMArena Text: medicine and healthcare14561455GPT-5.1
LMArena Text: legal and government14591441GPT-5.1
LMArena Text: business and finance14311435Qwen3.5 397B A17B
Neither model has a result on the other 3 boards here
Web designLike-for-likePublic boards, shown as published, kept out of the index43
Web design benchmarks for GPT-5.1 and Qwen3.5 397B A17B
BenchmarkGPT-5.1Qwen3.5 397B A17BLeader
Design Arena: websites11871191Qwen3.5 397B A17B
Design Arena: UI components11661163GPT-5.1
Design Arena: game dev11791141GPT-5.1
Design Arena: data viz12041175GPT-5.1
Design Arena: 3D10611161Qwen3.5 397B A17B
Design Arena: all code categories11711180Qwen3.5 397B A17B
Design Arena: SVG11491139GPT-5.1
Design Arena: ASCII art1118Not measuredOnly GPT-5.1 measured
Neither model has a result on the other 1 board here
GeneralLike-for-likePublic boards, shown as published, kept out of the index1811
General benchmarks for GPT-5.1 and Qwen3.5 397B A17B
BenchmarkGPT-5.1Qwen3.5 397B A17BLeader
SAGE (Vals AI)43.2%Not measuredOnly GPT-5.1 measured
MedScribe (Vals AI)88.1%Not measuredOnly GPT-5.1 measured
IFBench72.9%78.8%Qwen3.5 397B A17B
Long context reasoning (AA-LCR)80.0%77.3%GPT-5.1
DTBench90.1%87.5%GPT-5.1
LMCA43.9%37.9%GPT-5.1
CL-bench23.7%Not measuredOnly GPT-5.1 measured
CL-bench Life17.3%Not measuredOnly GPT-5.1 measured
LMArena Text14431437GPT-5.1
LMArena Text: instruction following14431424GPT-5.1
LMArena Text: creative writing14271402GPT-5.1
LMArena Vision12501262Qwen3.5 397B A17B
LMArena Text: English14511443GPT-5.1
LMArena Text: non-English14311430GPT-5.1
LMArena Text: Chinese14951498Qwen3.5 397B A17B
LMArena Text: German14381445Qwen3.5 397B A17B
LMArena Text: Japanese14531429GPT-5.1
LMArena Text: Korean14011384GPT-5.1
LMArena Text: French14501462Qwen3.5 397B A17B
LMArena Text: Spanish14331441Qwen3.5 397B A17B
LMArena Text: Russian14351430GPT-5.1
LMArena Text: Polish14401447Qwen3.5 397B A17B
LMArena Text: multi-turn14501446GPT-5.1
LMArena Text: longer queries14481441GPT-5.1
LMArena Text: writing and language14281415GPT-5.1
LMArena Text: entertainment and media14151399GPT-5.1
LMArena Vision: English12521268Qwen3.5 397B A17B
LMArena Vision: Chinese12701314Qwen3.5 397B A17B
LMArena Vision: reading text12551271Qwen3.5 397B A17B
LMArena Vision: humor12631262GPT-5.1
LMArena Vision: captioning12521230GPT-5.1
LMArena Vision: recognizing things12321265Qwen3.5 397B A17B
LMArena Vision: creative writing12661260GPT-5.1
LMArena Document1403Not measuredOnly GPT-5.1 measured
Neither model has a result on the other 12 boards here
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
Image generation benchmarks for GPT-5.1 and Qwen3.5 397B A17B
BenchmarkGPT-5.1Qwen3.5 397B A17BLeader
Neither model has a result on 5 boards here

What each workload costs

Three fixed token mixes at each model's listed price, so per-token rates become a bill.

Chat turn

1K input + 500 output tokens

GPT-5.1$0.0063Fits in one request
Qwen3.5 397B A17B$0.0016Fits in one request

Qwen3.5 397B A17B costs less

Repository review

50K input + 3K output tokens

GPT-5.1$0.092Fits in one request
Qwen3.5 397B A17B$0.027Fits in one request

Qwen3.5 397B A17B costs less

Agent loop

200K input + 10K output tokens

GPT-5.1$0.350Fits in one request
Qwen3.5 397B A17B$0.101Fits in one request

Qwen3.5 397B A17B costs less

Listed OpenRouter rates, without cache or batch discounts. A workload that does not fit a model's context window would need splitting.

Specification differences

The leading value in a row is marked; a row with a missing value names no leader. Our two rows are marked in red.

Specifications of GPT-5.1 and Qwen3.5 397B A17B
SpecificationOpenAI GPT-5.1Qwen3.5 397B A17B
MakerOpenAIQwen
WeightsNo public weights listedOpen weights
ReleasedNovember 13, 2025February 16, 2026
Context window400K262K
Input $/Mtok$1.25$0.39
Output $/Mtok$10.00$2.34
Coding index53.328.6
Independent measurements behind it21
Cost per solved task$1.02Not computable
SourceOpenRouter listingOpenRouter listing

Questions

Is GPT-5.1 better than Qwen3.5 397B A17B for coding?

Pick GPT-5.1 for coding: it scores 53.3 on the Vibe Coding Index against 28.6 for Qwen3.5 397B A17B. Pick Qwen3.5 397B A17B when output tokens cost 4.3x less, or when what matters is LMArena WebDev or LMArena Text: coding, where it leads.

Which is cheaper, GPT-5.1 or Qwen3.5 397B A17B?

GPT-5.1 costs $1.25 per million input tokens and $10.00 per million output tokens; Qwen3.5 397B A17B costs $0.39 and $2.34. Cost per solved task is known for GPT-5.1 only.

Which has the bigger context window, GPT-5.1 or Qwen3.5 397B A17B?

GPT-5.1, with 400K tokens against 262K.

How many benchmarks is the GPT-5.1 vs Qwen3.5 397B A17B comparison based on?

61 benchmarks have a result for both models as of October 21, 2026. GPT-5.1's coding index rests on 2 independent benchmarks and Qwen3.5 397B A17B's on 1. Where only one model has a result, the page says so instead of naming a winner.

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