GPT-5.1-Codex-Mini vs Qwen3.5 Plus 2026-02-15
Qwen3.5 Plus 2026-02-15 costs 1.3x less per output token than GPT-5.1-Codex-Mini ($1.56 vs $2.00 per million). Updated October 22, 2026; 8 benchmarks have a result for both.
GPT-5.1-Codex-Mini or Qwen3.5 Plus 2026-02-15: which to pick
Neither model has a coding score yet, so the two cannot be ranked on coding.
Pick GPT-5.1-Codex-Mini for work measured by Design Arena: websites or Design Arena: UI components, where it leads.
- Shared results
- 8
- GPT-5.1-Codex-Mini only
- 14
- Qwen3.5 Plus 2026-02-15 only
- 0
- Like-for-like categories
- 1 of 9
Only benchmarks that tested both models count toward a pick; a result only one model has is shown but not compared.
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, six public coding benchmarks
No call
Neither has a coding score yet.
One side not measured
Intelligence
AA Intelligence Index
No call
Only GPT-5.1-Codex-Mini has a AA Intelligence Index result, 20.4.
Directional only
Web design
Design Arena: websites
Qwen3.5 Plus 2026-02-15
Qwen3.5 Plus 2026-02-15 leads, 1187 against 1111.
Same board, both measured
Long documents
Listed context window
Qwen3.5 Plus 2026-02-15
Qwen3.5 Plus 2026-02-15 takes 1M tokens against 400K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Qwen3.5 Plus 2026-02-15
GPT-5.1-Codex-Mini $0.0013, Qwen3.5 Plus 2026-02-15 $0.0010 per turn.
List prices
At a glance
- Coding index
- GPT-5.1-Codex-Mini not benchmarked, Qwen3.5 Plus 2026-02-15 not benchmarked.
- Widest category
- Web design, 8.9 points apart on average over 8 shared benchmarks.
- Widest single gap
- Design Arena: 3D: GPT-5.1-Codex-Mini 988 against Qwen3.5 Plus 2026-02-15 1118, 16.3 points apart on a 0 to 100 scale.
- Output price
- GPT-5.1-Codex-Mini $2.00 against Qwen3.5 Plus 2026-02-15 $1.56 per million output tokens, 1.3x apart.
- Context window
- GPT-5.1-Codex-Mini takes 400K tokens, Qwen3.5 Plus 2026-02-15 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-Mini | Bars | Qwen3.5 Plus 2026-02-15 | Ties |
|---|---|---|---|---|
| Web design | 1 | 7 | ||
| All shared boards | 1 | 7 |
CodingDirectional onlySix of these boards feed the Vibe Coding Index5 boards, none shared
| Benchmark | GPT-5.1-Codex-Mini | Qwen3.5 Plus 2026-02-15 | Leader |
|---|---|---|---|
| LMArena WebDev | 1244 | Not measured | Only GPT-5.1-Codex-Mini measured |
| LiveCodeBench (Artificial Analysis run) | 83.6% | Not measured | Only GPT-5.1-Codex-Mini measured |
| Terminal-Bench Hard (Artificial Analysis run) | 33.3% | Not measured | Only GPT-5.1-Codex-Mini measured |
| Terminal-Bench | 61.6% | Not measured | Only GPT-5.1-Codex-Mini measured |
| LMArena WebDev: HTML | 1253 | Not measured | Only GPT-5.1-Codex-Mini measured |
| Neither model has a result on the other 34 boards here | |||
IntelligenceDirectional onlyPublic boards, shown as published, kept out of the index1 board, none shared
| Benchmark | GPT-5.1-Codex-Mini | Qwen3.5 Plus 2026-02-15 | Leader |
|---|---|---|---|
| AA Intelligence Index | 20.4 | Not measured | Only GPT-5.1-Codex-Mini measured |
| Neither model has a result on the other 1 board here | |||
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index1 board, none shared
| Benchmark | GPT-5.1-Codex-Mini | Qwen3.5 Plus 2026-02-15 | Leader |
|---|---|---|---|
| τ²-Bench Telecom | 62.9% | Not measured | Only GPT-5.1-Codex-Mini measured |
| Neither model has a result on the other 40 boards here | |||
ReasoningDirectional onlyPublic boards, shown as published, kept out of the index2 boards, none shared
| Benchmark | GPT-5.1-Codex-Mini | Qwen3.5 Plus 2026-02-15 | Leader |
|---|---|---|---|
| GPQA Diamond (Artificial Analysis run) | 81.3% | Not measured | Only GPT-5.1-Codex-Mini measured |
| Humanity's Last Exam (Artificial Analysis run) | 18.5% | Not measured | Only GPT-5.1-Codex-Mini measured |
| Neither model has a result on the other 20 boards here | |||
MathDirectional onlyPublic boards, shown as published, kept out of the index2 boards, none shared
| Benchmark | GPT-5.1-Codex-Mini | Qwen3.5 Plus 2026-02-15 | Leader |
|---|---|---|---|
| AA Math Index | 91.7 | Not measured | Only GPT-5.1-Codex-Mini measured |
| AIME 2025 (Artificial Analysis run) | 91.7% | Not measured | Only GPT-5.1-Codex-Mini measured |
| Neither model has a result on the other 11 boards here | |||
KnowledgeDirectional onlyPublic boards, shown as published, kept out of the index1 board, none shared
| Benchmark | GPT-5.1-Codex-Mini | Qwen3.5 Plus 2026-02-15 | Leader |
|---|---|---|---|
| MMLU Pro (Artificial Analysis run) | 82.0% | Not measured | Only GPT-5.1-Codex-Mini measured |
| Neither model has a result on the other 17 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index17
| Benchmark | GPT-5.1-Codex-Mini | Qwen3.5 Plus 2026-02-15 | Leader |
|---|---|---|---|
| Design Arena: websites | 1111 | 1187 | Qwen3.5 Plus 2026-02-15 |
| Design Arena: UI components | 1078 | 1175 | Qwen3.5 Plus 2026-02-15 |
| Design Arena: game dev | 1092 | 1105 | Qwen3.5 Plus 2026-02-15 |
| Design Arena: data viz | 1097 | 1135 | Qwen3.5 Plus 2026-02-15 |
| Design Arena: 3D | 988 | 1118 | Qwen3.5 Plus 2026-02-15 |
| Design Arena: all code categories | 1093 | 1166 | Qwen3.5 Plus 2026-02-15 |
| Design Arena: SVG | 978 | 1107 | Qwen3.5 Plus 2026-02-15 |
| Design Arena: ASCII art | 1105 | 1094 | GPT-5.1-Codex-Mini |
| Neither model has a result on the other 1 board here | |||
GeneralDirectional onlyPublic boards, shown as published, kept out of the index2 boards, none shared
| Benchmark | GPT-5.1-Codex-Mini | Qwen3.5 Plus 2026-02-15 | Leader |
|---|---|---|---|
| IFBench | 67.9% | Not measured | Only GPT-5.1-Codex-Mini measured |
| Long context reasoning (AA-LCR) | 66.7% | Not measured | Only GPT-5.1-Codex-Mini measured |
| Neither model has a result on the other 44 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | GPT-5.1-Codex-Mini | Qwen3.5 Plus 2026-02-15 | 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
Qwen3.5 Plus 2026-02-15 costs less
Repository review
50K input + 3K output tokens
Qwen3.5 Plus 2026-02-15 costs less
Agent loop
200K input + 10K output tokens
Qwen3.5 Plus 2026-02-15 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-Mini | Qwen3.5 Plus 2026-02-15 |
|---|---|---|
| Maker | OpenAI | Qwen |
| Weights | No public weights listed | No public weights listed |
| Released | November 13, 2025 | February 16, 2026 |
| Context window | 400K | 1M |
| Input $/Mtok | $0.25 | $0.26 |
| Output $/Mtok | $2.00 | $1.56 |
| Coding index | Not benchmarked | Not benchmarked |
| Independent measurements behind it | 1 | 0 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is GPT-5.1-Codex-Mini better than Qwen3.5 Plus 2026-02-15 for coding?
Neither model has a coding score yet, so the two cannot be ranked on coding. Pick GPT-5.1-Codex-Mini for work measured by Design Arena: websites or Design Arena: UI components, where it leads.
Which is cheaper, GPT-5.1-Codex-Mini or Qwen3.5 Plus 2026-02-15?
GPT-5.1-Codex-Mini costs $0.25 per million input tokens and $2.00 per million output tokens; Qwen3.5 Plus 2026-02-15 costs $0.26 and $1.56. Cost per solved task is known for neither of them.
Which has the bigger context window, GPT-5.1-Codex-Mini or Qwen3.5 Plus 2026-02-15?
Qwen3.5 Plus 2026-02-15, with 1M tokens against 400K.
How many benchmarks is the GPT-5.1-Codex-Mini vs Qwen3.5 Plus 2026-02-15 comparison based on?
8 benchmarks have a result for both models as of October 22, 2026. GPT-5.1-Codex-Mini's coding index rests on 1 independent benchmark and Qwen3.5 Plus 2026-02-15's on 0. Where only one model has a result, the page says so instead of naming a winner.