Noometry

Model comparison

GPT-5.5 Instant vs o3

o3 is the stronger model overall, scoring 47.5 to 42.7 on the Noometry Index.

Last verified . 24 shared benchmarks.

GPT-5.5 Instant OpenAI

42.7

Rank #110 Confirmed

o3 OpenAI

47.5

Rank #61 Confirmed

Summary

  • They share 24 benchmarks with published results for both. GPT-5.5 Instant scores higher in 2 categories and o3 in 7 categories; 9 gaps are clear of the uncertainty.
  • The widest gap is in math, where o3 leads 50.2 to 26.5.
  • The biggest single-benchmark swing is Chess Puzzles: 12% for GPT-5.5 Instant and 38% for o3.

Side by side

GPT-5.5 Instanto3
ProviderOpenAIOpenAI
Noometry Index42.747.5
Released2026-05-052025-04-16
WeightsProprietaryProprietary
Context window—200K
Max output—100K
Input $ / M tokens—$2
Output $ / M tokens—$8
Results tracked2763

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Category by category

Coding o3 leads

GPT-5.5 Instant: 44.3 (#74), o3: 46.8 (#64)

BenchmarkGPT-5.5 Instanto3
LMArena Coding14331408
SWE-bench Verified—62.3%
SWE-bench Verified (bash only)—58.4%
Aider Polyglot—81.3%
SciCode48.6%—
GSO—8.8%
WeirdML—52.4%
CadEval—74%
ALE-Bench—933.55

Agentic & Tool Use Not comparable

GPT-5.5 Instant: —, o3: 34.5 (#44)

BenchmarkGPT-5.5 Instanto3
Berkeley Function Calling Leaderboard—63%
GDPval—30.8%
DeepResearch Bench—45.2%
OSWorld—23%
LMArena Search—1144
METR Time Horizons—65.4%

Reasoning o3 leads

GPT-5.5 Instant: 24.9 (#155), o3: 32.0 (#78)

BenchmarkGPT-5.5 Instanto3
CritPt0%1.4%
Chess Puzzles12%38%
LMArena Hard Prompts14261402
Epoch Capabilities Index142.52146.86
ARC-AGI-2—6.5%
SimpleBench—53.1%
Kagi LLM Benchmark—67.6%
ARC-AGI-1—60.8%
EnigmaEval—13.1%
Mystery Game Puzzles—29%
DTBench—84.8%
LMCA—39.7%
ForecastBench—62.5

Math o3 leads

GPT-5.5 Instant: 26.5 (#259), o3: 50.2 (#58)

BenchmarkGPT-5.5 Instanto3
FrontierMath (Tiers 1-3)26.3%33.3%
OTIS Mock AIME 2024-202568.1%84.4%
LMArena Math14201426
FrontierMath Tier 42.4%—
Omni-MATH—71.4%
MATH Level 5—97.8%
FrontierMath (Feb 2025 set)—18.7%
FrontierMath Tier 4 (v1)—2.1%

Knowledge o3 leads

GPT-5.5 Instant: 48.9 (#74), o3: 54.6 (#52)

BenchmarkGPT-5.5 Instanto3
GPQA Diamond82.5%81.8%
LMArena Expert14091402
Humanity's Last Exam—20.3%
SimpleQA Verified—49.4%
MMLU-Pro—85.9%
Confabulations—14.4%
GPQA (HELM)—75.3%

Multimodal o3 leads

GPT-5.5 Instant: 40.0 (#52), o3: 41.4 (#36)

BenchmarkGPT-5.5 Instanto3
LMArena Vision12501214
GeoBench—74%
VPCT—52%
LMArena Document1403—

Multilingual GPT-5.5 Instant leads

GPT-5.5 Instant: 52.8 (#80), o3: 51.7 (#105)

BenchmarkGPT-5.5 Instanto3
LMArena Non-English14171401
LMArena Chinese14561437
LMArena French14281430
LMArena German14111420
LMArena Japanese14081403
LMArena Korean13921370
LMArena Russian14311406
LMArena Spanish14291395

Instruction Following GPT-5.5 Instant leads

GPT-5.5 Instant: 74.2 (#100), o3: 72.8 (#127)

BenchmarkGPT-5.5 Instanto3
LMArena Instruction Following14061368
IFEval—86.9%

Long Context o3 leads

GPT-5.5 Instant: 43.4 (#96), o3: 53.3 (#6)

BenchmarkGPT-5.5 Instanto3
LMArena Longer Query14221372
Fiction.LiveBench—88.9%
CL-bench—17.8%

Writing & Preference o3 leads

GPT-5.5 Instant: 61.8 (#85), o3: 63.5 (#64)

BenchmarkGPT-5.5 Instanto3
LMArena Text14191410
LMArena Creative Writing14191359
LMArena Multi-Turn14331405
Short-Story Creative Writing—83.9%
EQ-Bench Creative Writing—1676
WildBench—86.1%

Frequently asked questions

Is GPT-5.5 Instant better than o3?

o3 is the stronger model overall, scoring 47.5 to 42.7 on the Noometry Index.

Is GPT-5.5 Instant or o3 better for coding?

o3 scores higher on coding benchmarks: 46.8 versus 44.3 in the Noometry coding category.

How many benchmarks do GPT-5.5 Instant and o3 share?

24 benchmarks have published results for both models. GPT-5.5 Instant has 27 scored results on Noometry and o3 has 63.

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