GPT-5.1-Codex vs Qwen3.6 Plus
Updated October 21, 2026. 17 benchmarks have a result for both. Coding is ranked on the Vibe Coding Index; every other board is shown as published.
Decision reading
Pick GPT-5.1-Codex for coding: it scores 50.5 on the Vibe Coding Index against 37.4 for Qwen3.6 Plus.
Pick Qwen3.6 Plus when output tokens cost 5.1x less, or when the context window is larger, 1M against 400K tokens.
- Shared results
- 17
- GPT-5.1-Codex only
- 9
- Qwen3.6 Plus only
- 66
- Like-for-like categories
- 6 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.
Coding
Vibe Coding Index, four public coding benchmarks
GPT-5.1-Codex
GPT-5.1-Codex scores 50.5 against 37.4.
2 and 1 benchmarks behind the scores
Intelligence
AA Intelligence Index
Qwen3.6 Plus
Qwen3.6 Plus leads, 27.0 against 23.7.
Same board, both measured
Reasoning
GPQA Diamond
No call
Only Qwen3.6 Plus has a GPQA Diamond result, 87.4%.
Directional only
Math
AIME
No call
Only Qwen3.6 Plus has a AIME result, 94.6%.
Directional only
Knowledge
MMLU Pro
No call
Only Qwen3.6 Plus has a MMLU Pro result, 87.7%.
Directional only
Web design
Design Arena: websites
Qwen3.6 Plus
Qwen3.6 Plus leads, 1243 against 1162.
Same board, both measured
Long documents
Listed context window
Qwen3.6 Plus
Qwen3.6 Plus takes 1M tokens against 400K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Qwen3.6 Plus
GPT-5.1-Codex $0.0063, Qwen3.6 Plus $0.0013 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
GPT-5.1-Codex
GPT-5.1-Codex $0.892, Qwen3.6 Plus $1.19.
Published attempt cost and pass rate
At a glance
- Coding index
- GPT-5.1-Codex 50.5 from 2 benchmarks, Qwen3.6 Plus 37.4 from 1 benchmark.
- Widest category
- Agentic work, 14.6 points apart on average over 1 shared benchmark.
- Widest single gap
- LMArena WebDev: HTML: GPT-5.1-Codex 1346 against Qwen3.6 Plus 1463, 19.4 points apart on a 0 to 100 scale.
- Output price
- GPT-5.1-Codex $10.00 against Qwen3.6 Plus $1.95 per million output tokens, 5.1x apart.
- Context window
- GPT-5.1-Codex takes 400K tokens, Qwen3.6 Plus 1M.
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.
| Category | GPT-5.1-Codex | Bars | Qwen3.6 Plus | Ties |
|---|---|---|---|---|
| Coding | 1 | 5 | ||
| Intelligence | 0 | 1 | ||
| Agentic work | 0 | 1 | ||
| Reasoning | 0 | 2 | ||
| Web design | 1 | 4 | ||
| General | 0 | 2 | ||
| All shared boards | 2 | 15 |
CodingLike-for-likeFour of these boards feed the Vibe Coding Index15
| Benchmark | GPT-5.1-Codex | Qwen3.6 Plus | Leader |
|---|---|---|---|
| SWE-bench Verified | 66.0% | Not measured | Only GPT-5.1-Codex measured |
| LMArena WebDev | 1337 | 1461 | Qwen3.6 Plus |
| AA Coding Index | Not measured | 54.5 | Only Qwen3.6 Plus measured |
| LiveCodeBench (Vals AI) | 85.5% | 86.0% | Qwen3.6 Plus |
| SWE-bench Verified (Vals AI) | Not measured | 73.4% | Only Qwen3.6 Plus measured |
| Vibe Code Bench (Vals AI) | 13.1% | 25.6% | Qwen3.6 Plus |
| Code migration (Vals AI) | Not measured | 11.1% | Only Qwen3.6 Plus measured |
| ProgramBench (Vals AI) | Not measured | 0.0% | Only Qwen3.6 Plus measured |
| Terminal-Bench 2.1 (Vals AI) | Not measured | 53.2% | Only Qwen3.6 Plus measured |
| LiveCodeBench (Artificial Analysis run) | 84.9% | Not measured | Only GPT-5.1-Codex measured |
| Terminal-Bench Hard (Artificial Analysis run) | 34.8% | 43.9% | Qwen3.6 Plus |
| Terminal-Bench | 57.8% | Not measured | Only GPT-5.1-Codex measured |
| ALE-Bench | 1244.9 | 670.1 | GPT-5.1-Codex |
| LMArena Text: coding | Not measured | 1467 | Only Qwen3.6 Plus measured |
| LMArena Text: software and IT | Not measured | 1462 | Only Qwen3.6 Plus measured |
| LMArena WebDev: React | Not measured | 1454 | Only Qwen3.6 Plus measured |
| LMArena WebDev: HTML | 1346 | 1463 | Qwen3.6 Plus |
| LMArena WebDev: from an image | Not measured | 1472 | Only Qwen3.6 Plus measured |
| Neither model has a result on the other 20 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | GPT-5.1-Codex | Qwen3.6 Plus | Leader |
|---|---|---|---|
| AA Intelligence Index | 23.7 | 27.0 | Qwen3.6 Plus |
| Epoch Capabilities Index | Not measured | 147.3 | Only Qwen3.6 Plus measured |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | GPT-5.1-Codex | Qwen3.6 Plus | Leader |
|---|---|---|---|
| Design Arena: agents building web apps | 1018 | Not measured | Only GPT-5.1-Codex measured |
| Design Arena: agents building full-stack apps | 1086 | Not measured | Only GPT-5.1-Codex measured |
| Design Arena: agents building mobile apps | 1191 | Not measured | Only GPT-5.1-Codex measured |
| Finance Agent (Vals AI) | Not measured | 40.9% | Only Qwen3.6 Plus measured |
| Tax Agent Bench (Vals AI) | Not measured | 7.7% | Only Qwen3.6 Plus measured |
| Legal Research Bench (Vals AI) | Not measured | 14.9% | Only Qwen3.6 Plus measured |
| Excel Modeling Benchmark (Vals AI) | Not measured | 32.9% | Only Qwen3.6 Plus measured |
| τ²-Bench Telecom | 83.0% | 97.7% | Qwen3.6 Plus |
| Vending-Bench 2 | Not measured | $5,115 | Only Qwen3.6 Plus measured |
| Neither model has a result on the other 30 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index02
| Benchmark | GPT-5.1-Codex | Qwen3.6 Plus | Leader |
|---|---|---|---|
| GPQA Diamond | Not measured | 87.4% | Only Qwen3.6 Plus measured |
| MMMU Pro (Vals AI) | Not measured | 84.2% | Only Qwen3.6 Plus measured |
| GPQA Diamond (Artificial Analysis run) | 86.0% | 88.2% | Qwen3.6 Plus |
| Humanity's Last Exam (Artificial Analysis run) | 25.7% | 27.8% | Qwen3.6 Plus |
| GPQA Diamond (Epoch AI run) | Not measured | 88.4% | Only Qwen3.6 Plus measured |
| Chess puzzles | Not measured | 14.0% | Only Qwen3.6 Plus measured |
| Mystery game puzzles | Not measured | 12.0% | Only Qwen3.6 Plus measured |
| LMArena Text: hard prompts | Not measured | 1448 | Only Qwen3.6 Plus measured |
| LMArena Text: expert | Not measured | 1454 | Only Qwen3.6 Plus measured |
| LMArena Text: hard prompts in English | Not measured | 1455 | Only Qwen3.6 Plus measured |
| Neither model has a result on the other 11 boards here | |||
MathDirectional onlyPublic boards, shown as published, kept out of the index7 boards, none shared
| Benchmark | GPT-5.1-Codex | Qwen3.6 Plus | Leader |
|---|---|---|---|
| AIME | Not measured | 94.6% | Only Qwen3.6 Plus measured |
| AA Math Index | 95.7 | Not measured | Only GPT-5.1-Codex measured |
| AIME 2025 (Artificial Analysis run) | 95.7% | Not measured | Only GPT-5.1-Codex measured |
| OTIS Mock AIME | Not measured | 93.3% | Only Qwen3.6 Plus measured |
| FrontierMath, tiers 1 to 3 | Not measured | 38.2% | Only Qwen3.6 Plus measured |
| LMArena Text: math | Not measured | 1449 | Only Qwen3.6 Plus measured |
| LMArena Text: mathematical work | Not measured | 1448 | Only Qwen3.6 Plus measured |
| Neither model has a result on the other 6 boards here | |||
KnowledgeDirectional onlyPublic boards, shown as published, kept out of the index13 boards, none shared
| Benchmark | GPT-5.1-Codex | Qwen3.6 Plus | Leader |
|---|---|---|---|
| MMLU Pro | Not measured | 87.7% | Only Qwen3.6 Plus measured |
| LegalBench (Vals AI) | Not measured | 84.2% | Only Qwen3.6 Plus measured |
| CaseLaw (Vals AI) | Not measured | 51.5% | Only Qwen3.6 Plus measured |
| CorpFin (Vals AI) | Not measured | 61.9% | Only Qwen3.6 Plus measured |
| TaxEval (Vals AI) | Not measured | 74.7% | Only Qwen3.6 Plus measured |
| MortgageTax (Vals AI) | Not measured | 68.0% | Only Qwen3.6 Plus measured |
| MedCode (Vals AI) | Not measured | 36.9% | Only Qwen3.6 Plus measured |
| MMLU Pro (Artificial Analysis run) | 86.0% | Not measured | Only GPT-5.1-Codex measured |
| SimpleQA Verified | Not measured | 44.1% | Only Qwen3.6 Plus measured |
| LMArena Text: science | Not measured | 1439 | Only Qwen3.6 Plus measured |
| LMArena Text: medicine and healthcare | Not measured | 1442 | Only Qwen3.6 Plus measured |
| LMArena Text: legal and government | Not measured | 1437 | Only Qwen3.6 Plus measured |
| LMArena Text: business and finance | Not measured | 1430 | Only Qwen3.6 Plus measured |
| Neither model has a result on the other 4 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index14
| Benchmark | GPT-5.1-Codex | Qwen3.6 Plus | Leader |
|---|---|---|---|
| Design Arena: websites | 1162 | 1243 | Qwen3.6 Plus |
| Design Arena: UI components | 1237 | 1233 | GPT-5.1-Codex |
| Design Arena: game dev | 1138 | 1211 | Qwen3.6 Plus |
| Design Arena: data viz | 1213 | 1228 | Qwen3.6 Plus |
| Design Arena: 3D | Not measured | 1202 | Only Qwen3.6 Plus measured |
| Design Arena: all code categories | 1153 | 1236 | Qwen3.6 Plus |
| Design Arena: SVG | Not measured | 1160 | Only Qwen3.6 Plus measured |
| Design Arena: ASCII art | Not measured | 1115 | Only Qwen3.6 Plus measured |
| Neither model has a result on the other 1 board here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index02
| Benchmark | GPT-5.1-Codex | Qwen3.6 Plus | Leader |
|---|---|---|---|
| SAGE (Vals AI) | Not measured | 44.9% | Only Qwen3.6 Plus measured |
| MedScribe (Vals AI) | Not measured | 77.0% | Only Qwen3.6 Plus measured |
| Vals Multimodal Index | Not measured | 51.5% | Only Qwen3.6 Plus measured |
| IFBench | 70.0% | 75.2% | Qwen3.6 Plus |
| Long context reasoning (AA-LCR) | 69.3% | 78.3% | Qwen3.6 Plus |
| DTBench | Not measured | 81.9% | Only Qwen3.6 Plus measured |
| LMCA | Not measured | 33.1% | Only Qwen3.6 Plus measured |
| CL-bench | Not measured | 20.3% | Only Qwen3.6 Plus measured |
| LMArena Text | Not measured | 1436 | Only Qwen3.6 Plus measured |
| LMArena Text: instruction following | Not measured | 1424 | Only Qwen3.6 Plus measured |
| LMArena Text: creative writing | Not measured | 1404 | Only Qwen3.6 Plus measured |
| LMArena Text: English | Not measured | 1445 | Only Qwen3.6 Plus measured |
| LMArena Text: non-English | Not measured | 1424 | Only Qwen3.6 Plus measured |
| LMArena Text: Chinese | Not measured | 1477 | Only Qwen3.6 Plus measured |
| LMArena Text: German | Not measured | 1451 | Only Qwen3.6 Plus measured |
| LMArena Text: Japanese | Not measured | 1390 | Only Qwen3.6 Plus measured |
| LMArena Text: Korean | Not measured | 1379 | Only Qwen3.6 Plus measured |
| LMArena Text: French | Not measured | 1455 | Only Qwen3.6 Plus measured |
| LMArena Text: Spanish | Not measured | 1432 | Only Qwen3.6 Plus measured |
| LMArena Text: Russian | Not measured | 1434 | Only Qwen3.6 Plus measured |
| LMArena Text: Polish | Not measured | 1433 | Only Qwen3.6 Plus measured |
| LMArena Text: multi-turn | Not measured | 1438 | Only Qwen3.6 Plus measured |
| LMArena Text: longer queries | Not measured | 1439 | Only Qwen3.6 Plus measured |
| LMArena Text: writing and language | Not measured | 1418 | Only Qwen3.6 Plus measured |
| LMArena Text: entertainment and media | Not measured | 1402 | Only Qwen3.6 Plus measured |
| Neither model has a result on the other 21 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | GPT-5.1-Codex | Qwen3.6 Plus | Leader |
|---|---|---|---|
| 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
Qwen3.6 Plus costs less
Repository review
50K input + 3K output tokens
Qwen3.6 Plus costs less
Agent loop
200K input + 10K output tokens
Qwen3.6 Plus 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.
| Specification | OpenAI GPT-5.1-Codex | Qwen3.6 Plus |
|---|---|---|
| Maker | OpenAI | Qwen |
| Weights | No public weights listed | No public weights listed |
| Released | November 13, 2025 | April 2, 2026 |
| Context window | 400K | 1M |
| Input $/Mtok | $1.25 | $0.325 |
| Output $/Mtok | $10.00 | $1.95 |
| Coding index | 50.5 | 37.4 |
| Independent measurements behind it | 2 | 1 |
| Cost per solved task | $0.892 | $1.19 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is GPT-5.1-Codex better than Qwen3.6 Plus for coding?
Pick GPT-5.1-Codex for coding: it scores 50.5 on the Vibe Coding Index against 37.4 for Qwen3.6 Plus. Pick Qwen3.6 Plus when output tokens cost 5.1x less, or when the context window is larger, 1M against 400K tokens.
Which is cheaper, GPT-5.1-Codex or Qwen3.6 Plus?
GPT-5.1-Codex costs $1.25 per million input tokens and $10.00 per million output tokens; Qwen3.6 Plus costs $0.325 and $1.95. Per solved SWE-bench Verified task, GPT-5.1-Codex costs $0.892 and Qwen3.6 Plus $1.19.
Which has the bigger context window, GPT-5.1-Codex or Qwen3.6 Plus?
Qwen3.6 Plus, with 1M tokens against 400K.
How many benchmarks is the GPT-5.1-Codex vs Qwen3.6 Plus comparison based on?
17 benchmarks have a result for both models as of October 21, 2026. GPT-5.1-Codex's coding index rests on 2 independent benchmarks and Qwen3.6 Plus's on 1. Where only one model has a result, the page says so instead of naming a winner.