Model comparison

GPT-5.1-Codex-mini vs Muse Spark 1.2

Muse Spark 1.2 has enough public results to be ranked (#48); GPT-5.1-Codex-mini does not yet, so treat this comparison as directional.

Last verified . 1 shared benchmarks.

GPT-5.1-Codex-mini OpenAI

37.3

Unranked Sparse

Muse Spark 1.2 Meta

50.3

Rank #48 Confirmed

Summary

  • They share 1 benchmark with published results for both. GPT-5.1-Codex-mini scores higher in 1 category and Muse Spark 1.2 in 1 category; 2 gaps are clear of the uncertainty.
  • The widest gap is in coding, where Muse Spark 1.2 leads 49.2 to 31.6.
  • GPT-5.1-Codex-mini is cheaper at $0.25 / $2 per million input/output tokens, against $1.25 / $4.25 for Muse Spark 1.2.
  • Muse Spark 1.2 accepts more context: 1.05M tokens versus 400K.

Side by side

GPT-5.1-Codex-mini and Muse Spark 1.2 specifications
GPT-5.1-Codex-miniMuse Spark 1.2
ProviderOpenAIMeta
Noometry Index37.350.3
Released2025-11-122026-08-05
WeightsProprietaryProprietary
Context window400K1.05M
Max output128K131K
Input $ / M tokens$0.25$1.25
Output $ / M tokens$2$4.25
Results tracked231

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Category by category

Coding Muse Spark 1.2 leads

GPT-5.1-Codex-mini: 31.6, Muse Spark 1.2: 49.2 (#51)

Coding benchmarks
BenchmarkGPT-5.1-Codex-miniMuse Spark 1.2
LMArena WebDev12441533
DeepSWE—54.9%
FrontierSWE—12%
SciCode—56.4%
WeirdML—60.3%
LMArena Coding—1495

Agentic & Tool Use GPT-5.1-Codex-mini leads

GPT-5.1-Codex-mini: 38.5, Muse Spark 1.2: 29.4 (#87)

Agentic & Tool Use benchmarks
BenchmarkGPT-5.1-Codex-miniMuse Spark 1.2
Terminal-Bench61.6%—
APEX-Agents—36.4%
GDP.pdf—16%

Reasoning Not comparable

GPT-5.1-Codex-mini: —, Muse Spark 1.2: 51.3 (#34)

Reasoning benchmarks
BenchmarkGPT-5.1-Codex-miniMuse Spark 1.2
SimpleBench—74.5%
NYT Connections (extended)—79.2%
CritPt—17.7%
LMArena Hard Prompts—1486
DTBench—94.7%
LMCA—48.4%
Epoch Capabilities Index—154.87

Math Not comparable

GPT-5.1-Codex-mini: —, Muse Spark 1.2: 46.4 (#70)

Math benchmarks
BenchmarkGPT-5.1-Codex-miniMuse Spark 1.2
ProofBench—43%
LMArena Math—1471

Knowledge Not comparable

GPT-5.1-Codex-mini: —, Muse Spark 1.2: 54.1 (#53)

Knowledge benchmarks
BenchmarkGPT-5.1-Codex-miniMuse Spark 1.2
SimpleQA Verified—60.3%
LMArena Expert—1480

Multimodal Not comparable

GPT-5.1-Codex-mini: —, Muse Spark 1.2: 43.4 (#25)

Multimodal benchmarks
BenchmarkGPT-5.1-Codex-miniMuse Spark 1.2
LMArena Vision—1305

Multilingual Not comparable

GPT-5.1-Codex-mini: —, Muse Spark 1.2: 57.1 (#11)

Multilingual benchmarks
BenchmarkGPT-5.1-Codex-miniMuse Spark 1.2
LMArena Non-English—1478
LMArena Chinese—1511
LMArena French—1513
LMArena Russian—1487
LMArena Spanish—1498

Instruction Following Not comparable

GPT-5.1-Codex-mini: —, Muse Spark 1.2: 76.7 (#36)

Instruction Following benchmarks
BenchmarkGPT-5.1-Codex-miniMuse Spark 1.2
LMArena Instruction Following—1461

Long Context Not comparable

GPT-5.1-Codex-mini: —, Muse Spark 1.2: 45.2 (#48)

Long Context benchmarks
BenchmarkGPT-5.1-Codex-miniMuse Spark 1.2
LMArena Longer Query—1475

Writing & Preference Not comparable

GPT-5.1-Codex-mini: —, Muse Spark 1.2: 72.3 (#14)

Writing & Preference benchmarks
BenchmarkGPT-5.1-Codex-miniMuse Spark 1.2
LMArena Text—1482
LMArena Creative Writing—1449
EQ-Bench Creative Writing—1840
LMArena Multi-Turn—1494

Frequently asked questions

Is GPT-5.1-Codex-mini better than Muse Spark 1.2?

Muse Spark 1.2 has enough public results to be ranked (#48); GPT-5.1-Codex-mini does not yet, so treat this comparison as directional.

Which is cheaper, GPT-5.1-Codex-mini or Muse Spark 1.2?

GPT-5.1-Codex-mini is cheaper. It lists at $0.25 per million input tokens and $2 per million output tokens; Muse Spark 1.2 lists at $1.25 and $4.25.

Is GPT-5.1-Codex-mini or Muse Spark 1.2 better for coding?

Muse Spark 1.2 scores higher on coding benchmarks: 49.2 versus 31.6 in the Noometry coding category.

Which has the bigger context window?

Muse Spark 1.2 does, with 1.05M tokens against 400K.

How many benchmarks do GPT-5.1-Codex-mini and Muse Spark 1.2 share?

1 benchmark has published results for both models. GPT-5.1-Codex-mini has 2 scored results on Noometry and Muse Spark 1.2 has 31.

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