Model comparison

GPT-5-Codex vs Llama 3-8B

GPT-5-Codex is the stronger model overall, scoring 37.9 to 25.5 on the Noometry Index.

Last verified . 0 shared benchmarks.

GPT-5-Codex OpenAI

37.9

Rank #192 Reported

Llama 3-8B Meta

25.5

Rank #344 Confirmed

Summary

  • The widest gap is in reasoning, where GPT-5-Codex leads 30.9 to 14.3.
  • Llama 3-8B has downloadable open weights; the other is API-only.

Side by side

GPT-5-Codex and Llama 3-8B specifications
GPT-5-CodexLlama 3-8B
ProviderOpenAIMeta
Noometry Index37.925.5
Released2025-09-152024-04-18
WeightsProprietaryOpen
Context window400K—
Max output128K—
Input $ / M tokens$1.25—
Output $ / M tokens$10—
Results tracked334

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Category by category

Coding GPT-5-Codex leads

GPT-5-Codex: 42.4 (#103), Llama 3-8B: 31.0 (#289)

Coding benchmarks
BenchmarkGPT-5-CodexLlama 3-8B
WeirdML54.5%—
BigCodeBench Instruct—31.9%
LMArena Coding—1152
BigCodeBench Complete—36.9%
HumanEval+—56.7%
MBPP+—54.8%

Agentic & Tool Use Not comparable

GPT-5-Codex: 31.0 (#72), Llama 3-8B: —

Agentic & Tool Use benchmarks
BenchmarkGPT-5-CodexLlama 3-8B
Terminal-Bench44.3%—

Reasoning GPT-5-Codex leads

GPT-5-Codex: 30.9 (#83), Llama 3-8B: 14.3 (#326)

Reasoning benchmarks
BenchmarkGPT-5-CodexLlama 3-8B
Kagi LLM Benchmark70.3%—
Chess Puzzles—0%
LMArena Hard Prompts—1133
DTBench—43.9%
Adversarial NLI—57.3%
Epoch Capabilities Index—116.45
ForecastBench—58.6
WinoGrande—75.7%

Math Not comparable

GPT-5-Codex: —, Llama 3-8B: 8.8 (#323)

Math benchmarks
BenchmarkGPT-5-CodexLlama 3-8B
OTIS Mock AIME 2024-2025—1.9%
LMArena Math—1151
MATH Level 5—6.1%

Knowledge Not comparable

GPT-5-Codex: —, Llama 3-8B: 7.8 (#308)

Knowledge benchmarks
BenchmarkGPT-5-CodexLlama 3-8B
GPQA Diamond—26.1%
LMArena Expert—1113
ARC (AI2) Challenge—82.8%
MMLU—68.8%
OpenBookQA—82.6%
TriviaQA—67.7%

Multilingual Not comparable

GPT-5-Codex: —, Llama 3-8B: 30.8 (#261)

Multilingual benchmarks
BenchmarkGPT-5-CodexLlama 3-8B
LMArena Non-English—1098
LMArena Chinese—1076
LMArena French—1159
LMArena German—1104
LMArena Japanese—967
LMArena Korean—1004
LMArena Russian—1109
LMArena Spanish—1173

Instruction Following Not comparable

GPT-5-Codex: —, Llama 3-8B: 58.4 (#260)

Instruction Following benchmarks
BenchmarkGPT-5-CodexLlama 3-8B
LMArena Instruction Following—1127

Long Context Not comparable

GPT-5-Codex: —, Llama 3-8B: 34.2 (#251)

Long Context benchmarks
BenchmarkGPT-5-CodexLlama 3-8B
LMArena Longer Query—1128

Writing & Preference Not comparable

GPT-5-Codex: —, Llama 3-8B: 37.5 (#256)

Writing & Preference benchmarks
BenchmarkGPT-5-CodexLlama 3-8B
LMArena Text—1166
LMArena Creative Writing—1150
LMArena Multi-Turn—1152

Frequently asked questions

Is GPT-5-Codex better than Llama 3-8B?

GPT-5-Codex is the stronger model overall, scoring 37.9 to 25.5 on the Noometry Index.

Is GPT-5-Codex or Llama 3-8B better for coding?

GPT-5-Codex scores higher on coding benchmarks: 42.4 versus 31.0 in the Noometry coding category.

How many benchmarks do GPT-5-Codex and Llama 3-8B share?

0 benchmarks have published results for both models. GPT-5-Codex has 3 scored results on Noometry and Llama 3-8B has 34.

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