Model comparison

GPT-5.3 Codex vs Qwen3.5 27B

GPT-5.3 Codex is the stronger model overall, scoring 45.8 to 41.9 on the Noometry Index. Qwen3.5 27B costs 5.8× less per token, which makes it the better buy when GPT-5.3 Codex's lead doesn't matter for your workload.

Last verified . 4 shared benchmarks.

GPT-5.3 Codex OpenAI

45.8

Rank #69 Reported

Qwen3.5 27B Alibaba (Qwen)

41.9

Rank #127 Confirmed

Summary

  • They share 4 benchmarks with published results for both. GPT-5.3 Codex scores higher in 1 category and Qwen3.5 27B in 0 categories; one gap is clear of the uncertainty.
  • The widest gap is in coding, where GPT-5.3 Codex leads 48.6 to 38.9.
  • The biggest single-benchmark swing is WeirdML: 79.3% for GPT-5.3 Codex and 39.5% for Qwen3.5 27B.
  • Qwen3.5 27B is cheaper at $0.30 / $2.40 per million input/output tokens, against $1.75 / $14 for GPT-5.3 Codex.
  • GPT-5.3 Codex accepts more context: 400K tokens versus 262K.
  • Qwen3.5 27B has downloadable open weights; the other is API-only.

Side by side

GPT-5.3 Codex and Qwen3.5 27B specifications
GPT-5.3 CodexQwen3.5 27B
ProviderOpenAIAlibaba (Qwen)
Noometry Index45.841.9
Released2026-02-052026-02-23
WeightsProprietaryOpen
Context window400K262K
Max output128K66K
Input $ / M tokens$1.75$0.30
Output $ / M tokens$14$2.40
Results tracked828

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Category by category

Coding GPT-5.3 Codex leads

GPT-5.3 Codex: 48.6 (#56), Qwen3.5 27B: 38.9 (#168)

Coding benchmarks
BenchmarkGPT-5.3 CodexQwen3.5 27B
LMArena WebDev14091358
WeirdML79.3%39.5%
ALE-Bench1,655349.45
SWE-bench Verified74.8%—
LMArena Coding—1427

Agentic & Tool Use Not comparable

GPT-5.3 Codex: 48.0 (#9), Qwen3.5 27B: —

Agentic & Tool Use benchmarks
BenchmarkGPT-5.3 CodexQwen3.5 27B
Vending-Bench 25,940201.98
Terminal-Bench78.4%—
METR Time Horizons74.5%—

Reasoning Not comparable

GPT-5.3 Codex: —, Qwen3.5 27B: 27.5 (#117)

Reasoning benchmarks
BenchmarkGPT-5.3 CodexQwen3.5 27B
NYT Connections (extended)—47.9%
Thematic Generalization—45.5%
LMArena Hard Prompts—1414
DTBench—82.4%
LMCA—34%
Epoch Capabilities Index156.77—

Math Not comparable

GPT-5.3 Codex: —, Qwen3.5 27B: 38.8 (#127)

Math benchmarks
BenchmarkGPT-5.3 CodexQwen3.5 27B
MathArena Final-Answer Competitions—56.7%
LMArena Math—1429

Knowledge Not comparable

GPT-5.3 Codex: —, Qwen3.5 27B: 38.0 (#150)

Knowledge benchmarks
BenchmarkGPT-5.3 CodexQwen3.5 27B
Vectara Hallucination Rate—12.1%
LMArena Expert—1428

Multimodal Not comparable

GPT-5.3 Codex: —, Qwen3.5 27B: 39.4 (#59)

Multimodal benchmarks
BenchmarkGPT-5.3 CodexQwen3.5 27B
LMArena Vision—1241

Multilingual Not comparable

GPT-5.3 Codex: —, Qwen3.5 27B: 50.8 (#115)

Multilingual benchmarks
BenchmarkGPT-5.3 CodexQwen3.5 27B
LMArena Non-English—1390
LMArena Chinese—1478
LMArena French—1410
LMArena German—1393
LMArena Japanese—1345
LMArena Korean—1358
LMArena Russian—1390
LMArena Spanish—1407

Instruction Following Not comparable

GPT-5.3 Codex: —, Qwen3.5 27B: 73.5 (#119)

Instruction Following benchmarks
BenchmarkGPT-5.3 CodexQwen3.5 27B
LMArena Instruction Following—1393

Long Context Not comparable

GPT-5.3 Codex: —, Qwen3.5 27B: 43.1 (#106)

Long Context benchmarks
BenchmarkGPT-5.3 CodexQwen3.5 27B
LMArena Longer Query—1413

Writing & Preference Not comparable

GPT-5.3 Codex: —, Qwen3.5 27B: 59.3 (#111)

Writing & Preference benchmarks
BenchmarkGPT-5.3 CodexQwen3.5 27B
LMArena Text—1409
LMArena Creative Writing—1362
LMArena Multi-Turn—1410

Frequently asked questions

Is GPT-5.3 Codex better than Qwen3.5 27B?

GPT-5.3 Codex is the stronger model overall, scoring 45.8 to 41.9 on the Noometry Index. Qwen3.5 27B costs 5.8× less per token, which makes it the better buy when GPT-5.3 Codex's lead doesn't matter for your workload.

Which is cheaper, GPT-5.3 Codex or Qwen3.5 27B?

Qwen3.5 27B is cheaper. It lists at $0.30 per million input tokens and $2.40 per million output tokens; GPT-5.3 Codex lists at $1.75 and $14.

Is GPT-5.3 Codex or Qwen3.5 27B better for coding?

GPT-5.3 Codex scores higher on coding benchmarks: 48.6 versus 38.9 in the Noometry coding category.

Which has the bigger context window?

GPT-5.3 Codex does, with 400K tokens against 262K.

How many benchmarks do GPT-5.3 Codex and Qwen3.5 27B share?

4 benchmarks have published results for both models. GPT-5.3 Codex has 8 scored results on Noometry and Qwen3.5 27B has 28.

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