Model comparison

GPT-5-Codex vs Muse Spark 1.3

Muse Spark 1.3 is the stronger model overall, scoring 54.8 to 37.9 on the Noometry Index.

Last verified . 0 shared benchmarks.

GPT-5-Codex OpenAI

37.9

Rank #192 Reported

Muse Spark 1.3 Meta

54.8

Rank #27 Confirmed

Summary

  • The widest gap is in reasoning, where Muse Spark 1.3 leads 54.0 to 30.9.
  • Muse Spark 1.3 is cheaper at $1.25 / $4.25 per million input/output tokens, against $1.25 / $10 for GPT-5-Codex.
  • Muse Spark 1.3 accepts more context: 1.05M tokens versus 400K.

Side by side

GPT-5-Codex and Muse Spark 1.3 specifications
GPT-5-CodexMuse Spark 1.3
ProviderOpenAIMeta
Noometry Index37.954.8
Released2025-09-152026-09-02
WeightsProprietaryProprietary
Context window400K1.05M
Max output128K131K
Input $ / M tokens$1.25$1.25
Output $ / M tokens$10$4.25
Results tracked337

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Category by category

Coding Muse Spark 1.3 leads

GPT-5-Codex: 42.4 (#103), Muse Spark 1.3: 56.6 (#21)

Coding benchmarks
BenchmarkGPT-5-CodexMuse Spark 1.3
CursorBench—41.6%
LMArena WebDev—1657
SciCode—59.7%
WeirdML54.5%—
LMArena Coding—1514

Agentic & Tool Use Muse Spark 1.3 leads

GPT-5-Codex: 31.0 (#72), Muse Spark 1.3: 38.6 (#30)

Agentic & Tool Use benchmarks
BenchmarkGPT-5-CodexMuse Spark 1.3
Terminal-Bench44.3%—
APEX-Agents—57.8%
GDP.pdf—27.6%

Reasoning Muse Spark 1.3 leads

GPT-5-Codex: 30.9 (#83), Muse Spark 1.3: 54.0 (#27)

Reasoning benchmarks
BenchmarkGPT-5-CodexMuse Spark 1.3
Kagi LLM Benchmark70.3%—
NYT Connections (extended)—85.1%
CritPt—26%
Chess Puzzles—38%
LMArena Hard Prompts—1503
Mystery Game Puzzles—25%
DTBench—96.5%
LMCA—53.9%
Bench to the Future 3—0.14
Epoch Capabilities Index—156.75

Math Not comparable

GPT-5-Codex: —, Muse Spark 1.3: 73.1 (#21)

Math benchmarks
BenchmarkGPT-5-CodexMuse Spark 1.3
FrontierMath (Tiers 1-3)—74.4%
FrontierMath Tier 4—46.3%
OTIS Mock AIME 2024-2025—99.2%
ProofBench—58%
LMArena Math—1494

Knowledge Not comparable

GPT-5-Codex: —, Muse Spark 1.3: 42.6 (#95)

Knowledge benchmarks
BenchmarkGPT-5-CodexMuse Spark 1.3
LMArena Expert—1516

Multimodal Not comparable

GPT-5-Codex: —, Muse Spark 1.3: 43.7 (#22)

Multimodal benchmarks
BenchmarkGPT-5-CodexMuse Spark 1.3
LMArena Vision—1309
LMArena Document—1471

Multilingual Not comparable

GPT-5-Codex: —, Muse Spark 1.3: 57.4 (#8)

Multilingual benchmarks
BenchmarkGPT-5-CodexMuse Spark 1.3
LMArena Non-English—1481
LMArena Chinese—1529
LMArena French—1524
LMArena German—1515
LMArena Japanese—1474
LMArena Korean—1501
LMArena Russian—1490
LMArena Spanish—1490

Instruction Following Not comparable

GPT-5-Codex: —, Muse Spark 1.3: 77.5 (#22)

Instruction Following benchmarks
BenchmarkGPT-5-CodexMuse Spark 1.3
LMArena Instruction Following—1477

Long Context Not comparable

GPT-5-Codex: —, Muse Spark 1.3: 45.6 (#32)

Long Context benchmarks
BenchmarkGPT-5-CodexMuse Spark 1.3
LMArena Longer Query—1488

Writing & Preference Not comparable

GPT-5-Codex: —, Muse Spark 1.3: 73.6 (#9)

Writing & Preference benchmarks
BenchmarkGPT-5-CodexMuse Spark 1.3
LMArena Text—1490
LMArena Creative Writing—1455
EQ-Bench Creative Writing—1906
LMArena Multi-Turn—1482

Frequently asked questions

Is GPT-5-Codex better than Muse Spark 1.3?

Muse Spark 1.3 is the stronger model overall, scoring 54.8 to 37.9 on the Noometry Index.

Which is cheaper, GPT-5-Codex or Muse Spark 1.3?

Muse Spark 1.3 is cheaper. It lists at $1.25 per million input tokens and $4.25 per million output tokens; GPT-5-Codex lists at $1.25 and $10.

Is GPT-5-Codex or Muse Spark 1.3 better for coding?

Muse Spark 1.3 scores higher on coding benchmarks: 56.6 versus 42.4 in the Noometry coding category.

Which has the bigger context window?

Muse Spark 1.3 does, with 1.05M tokens against 400K.

How many benchmarks do GPT-5-Codex and Muse Spark 1.3 share?

0 benchmarks have published results for both models. GPT-5-Codex has 3 scored results on Noometry and Muse Spark 1.3 has 37.

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