Noometry

Model comparison

GPT-5.5 Instant vs Llama 3.1-405B

GPT-5.5 Instant is the stronger model overall, scoring 42.7 to 30.7 on the Noometry Index.

Last verified . 20 shared benchmarks.

GPT-5.5 Instant OpenAI

42.7

Rank #110 Confirmed

Llama 3.1-405B Meta

30.7

Rank #288 Confirmed

Summary

  • They share 20 benchmarks with published results for both. GPT-5.5 Instant scores higher in 8 categories and Llama 3.1-405B in 0 categories; 8 gaps are clear of the uncertainty.
  • The widest gap is in writing & preference, where GPT-5.5 Instant leads 61.8 to 38.9.
  • The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 68.1% for GPT-5.5 Instant and 9.7% for Llama 3.1-405B.
  • Llama 3.1-405B has downloadable open weights; the other is API-only.

Side by side

GPT-5.5 InstantLlama 3.1-405B
ProviderOpenAIMeta
Noometry Index42.730.7
Released2026-05-052024-07-23
WeightsProprietaryOpen
Context window——
Max output——
Input $ / M tokens——
Output $ / M tokens——
Results tracked2742

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Category by category

Coding GPT-5.5 Instant leads

GPT-5.5 Instant: 44.3 (#74), Llama 3.1-405B: 33.1 (#262)

BenchmarkGPT-5.5 InstantLlama 3.1-405B
LMArena Coding14331291
SciCode48.6%—
WeirdML—21.4%

Agentic & Tool Use Not comparable

GPT-5.5 Instant: —, Llama 3.1-405B: 21.0 (#140)

BenchmarkGPT-5.5 InstantLlama 3.1-405B
TheAgentCompany—7.4%
Cybench—7.5%

Reasoning GPT-5.5 Instant leads

GPT-5.5 Instant: 24.9 (#155), Llama 3.1-405B: 16.8 (#300)

BenchmarkGPT-5.5 InstantLlama 3.1-405B
LMArena Hard Prompts14261269
Epoch Capabilities Index142.52128.75
SimpleBench—23%
Kagi LLM Benchmark—45%
CritPt0%—
Chess Puzzles12%—
DTBench—61.4%
BIG-Bench Hard—82.9%
ForecastBench—59.9
HellaSwag—89.2%
PIQA—85.9%
WinoGrande—89.2%

Math GPT-5.5 Instant leads

GPT-5.5 Instant: 26.5 (#259), Llama 3.1-405B: 18.4 (#290)

BenchmarkGPT-5.5 InstantLlama 3.1-405B
OTIS Mock AIME 2024-202568.1%9.7%
LMArena Math14201281
FrontierMath (Tiers 1-3)26.3%—
FrontierMath Tier 42.4%—
Omni-MATH—24.9%
MATH Level 5—49.8%

Knowledge GPT-5.5 Instant leads

GPT-5.5 Instant: 48.9 (#74), Llama 3.1-405B: 30.4 (#227)

BenchmarkGPT-5.5 InstantLlama 3.1-405B
GPQA Diamond82.5%50.9%
LMArena Expert14091243
MMLU-Pro—72.3%
Confabulations—17.6%
GPQA (HELM)—52.2%
ARC (AI2) Challenge—95.3%
MMLU—84.5%
TriviaQA—82.7%

Multimodal Not comparable

GPT-5.5 Instant: 40.0 (#52), Llama 3.1-405B: —

BenchmarkGPT-5.5 InstantLlama 3.1-405B
LMArena Vision1250—
LMArena Document1403—

Multilingual GPT-5.5 Instant leads

GPT-5.5 Instant: 52.8 (#80), Llama 3.1-405B: 40.7 (#214)

BenchmarkGPT-5.5 InstantLlama 3.1-405B
LMArena Non-English14171248
LMArena Chinese14561242
LMArena French14281279
LMArena German14111252
LMArena Japanese14081208
LMArena Korean13921184
LMArena Russian14311265
LMArena Spanish14291260

Instruction Following GPT-5.5 Instant leads

GPT-5.5 Instant: 74.2 (#100), Llama 3.1-405B: 65.9 (#214)

BenchmarkGPT-5.5 InstantLlama 3.1-405B
LMArena Instruction Following14061259
IFEval—81.1%

Long Context GPT-5.5 Instant leads

GPT-5.5 Instant: 43.4 (#96), Llama 3.1-405B: 38.4 (#197)

BenchmarkGPT-5.5 InstantLlama 3.1-405B
LMArena Longer Query14221266

Writing & Preference GPT-5.5 Instant leads

GPT-5.5 Instant: 61.8 (#85), Llama 3.1-405B: 38.9 (#251)

BenchmarkGPT-5.5 InstantLlama 3.1-405B
LMArena Text14191284
LMArena Creative Writing14191262
LMArena Multi-Turn14331297
EQ-Bench Creative Writing—870
WildBench—78.3%

Frequently asked questions

Is GPT-5.5 Instant better than Llama 3.1-405B?

GPT-5.5 Instant is the stronger model overall, scoring 42.7 to 30.7 on the Noometry Index.

Is GPT-5.5 Instant or Llama 3.1-405B better for coding?

GPT-5.5 Instant scores higher on coding benchmarks: 44.3 versus 33.1 in the Noometry coding category.

How many benchmarks do GPT-5.5 Instant and Llama 3.1-405B share?

20 benchmarks have published results for both models. GPT-5.5 Instant has 27 scored results on Noometry and Llama 3.1-405B has 42.

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