Noometry

Model comparison

GPT-5.3 Codex vs Muse Spark 1.3

Muse Spark 1.3 is the stronger model overall, scoring 54.8 to 45.8 on the Noometry Index.

Last verified . 2 shared benchmarks.

GPT-5.3 Codex OpenAI

45.8

Rank #69 Reported

Muse Spark 1.3 Meta

54.8

Rank #27 Confirmed

Summary

  • They share 2 benchmarks with published results for both. GPT-5.3 Codex scores higher in 1 category and Muse Spark 1.3 in 1 category; 2 gaps are clear of the uncertainty.
  • The widest gap is in agentic & tool use, where GPT-5.3 Codex leads 48.0 to 38.6.
  • Muse Spark 1.3 is cheaper at $1.25 / $4.25 per million input/output tokens, against $1.75 / $14 for GPT-5.3 Codex.
  • Muse Spark 1.3 accepts more context: 1.05M tokens versus 400K.

Side by side

GPT-5.3 CodexMuse Spark 1.3
ProviderOpenAIMeta
Noometry Index45.854.8
Released2026-02-052026-09-02
WeightsProprietaryProprietary
Context window400K1.05M
Max output128K131K
Input $ / M tokens$1.75$1.25
Output $ / M tokens$14$4.25
Results tracked837

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Category by category

Coding Muse Spark 1.3 leads

GPT-5.3 Codex: 48.6 (#56), Muse Spark 1.3: 56.6 (#21)

BenchmarkGPT-5.3 CodexMuse Spark 1.3
LMArena WebDev14091657
SWE-bench Verified74.8%—
CursorBench—41.6%
SciCode—59.7%
WeirdML79.3%—
LMArena Coding—1514
ALE-Bench1,655—

Agentic & Tool Use GPT-5.3 Codex leads

GPT-5.3 Codex: 48.0 (#9), Muse Spark 1.3: 38.6 (#30)

BenchmarkGPT-5.3 CodexMuse Spark 1.3
Terminal-Bench78.4%—
APEX-Agents—57.8%
GDP.pdf—27.6%
METR Time Horizons74.5%—
Vending-Bench 25,940—

Reasoning Not comparable

GPT-5.3 Codex: —, Muse Spark 1.3: 54.0 (#27)

BenchmarkGPT-5.3 CodexMuse Spark 1.3
Epoch Capabilities Index156.77156.75
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

Math Not comparable

GPT-5.3 Codex: —, Muse Spark 1.3: 73.1 (#21)

BenchmarkGPT-5.3 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-5.3 Codex: —, Muse Spark 1.3: 42.6 (#95)

BenchmarkGPT-5.3 CodexMuse Spark 1.3
LMArena Expert—1516

Multimodal Not comparable

GPT-5.3 Codex: —, Muse Spark 1.3: 43.7 (#22)

BenchmarkGPT-5.3 CodexMuse Spark 1.3
LMArena Vision—1309
LMArena Document—1471

Multilingual Not comparable

GPT-5.3 Codex: —, Muse Spark 1.3: 57.4 (#8)

BenchmarkGPT-5.3 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-5.3 Codex: —, Muse Spark 1.3: 77.5 (#22)

BenchmarkGPT-5.3 CodexMuse Spark 1.3
LMArena Instruction Following—1477

Long Context Not comparable

GPT-5.3 Codex: —, Muse Spark 1.3: 45.6 (#32)

BenchmarkGPT-5.3 CodexMuse Spark 1.3
LMArena Longer Query—1488

Writing & Preference Not comparable

GPT-5.3 Codex: —, Muse Spark 1.3: 73.6 (#9)

BenchmarkGPT-5.3 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-5.3 Codex better than Muse Spark 1.3?

Muse Spark 1.3 is the stronger model overall, scoring 54.8 to 45.8 on the Noometry Index.

Which is cheaper, GPT-5.3 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-5.3 Codex lists at $1.75 and $14.

Is GPT-5.3 Codex or Muse Spark 1.3 better for coding?

Muse Spark 1.3 scores higher on coding benchmarks: 56.6 versus 48.6 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-5.3 Codex and Muse Spark 1.3 share?

2 benchmarks have published results for both models. GPT-5.3 Codex has 8 scored results on Noometry and Muse Spark 1.3 has 37.

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