Model comparison

GPT-5.5 vs o1

GPT-5.5 is the stronger model overall, scoring 63.4 to 40.9 on the Noometry Index.

Last verified . 30 shared benchmarks.

GPT-5.5 OpenAI

63.4

Rank #9 Confirmed

o1 OpenAI

40.9

Rank #143 Confirmed

Summary

  • They share 30 benchmarks with published results for both. GPT-5.5 scores higher in 9 categories and o1 in 1 category; 10 gaps are clear of the uncertainty.
  • The widest gap is in math, where GPT-5.5 leads 81.7 to 36.1.
  • The biggest single-benchmark swing is FrontierMath (Tiers 1-3): 85.3% for GPT-5.5 and 14.7% for o1.
  • GPT-5.5 is cheaper at $5 / $30 per million input/output tokens, against $15 / $60 for o1.
  • GPT-5.5 accepts more context: 1.05M tokens versus 200K.

Side by side

GPT-5.5 and o1 specifications
GPT-5.5o1
ProviderOpenAIOpenAI
Noometry Index63.440.9
Released2026-04-232024-09-12
WeightsProprietaryProprietary
Context window1.05M200K
Max output128K100K
Input $ / M tokens$5$15
Output $ / M tokens$30$60
Results tracked7152

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Category by category

Coding GPT-5.5 leads

GPT-5.5: 58.2 (#17), o1: 46.1 (#70)

Coding benchmarks
BenchmarkGPT-5.5o1
WeirdML84.9%47.6%
LMArena Coding14941367
SWE-bench Verified80.6%—
DeepSWE67%—
FrontierCode43%—
Aider Polyglot—61.7%
LMArena WebDev1513—
SciCode56.1%—
GSO40.2%—
LiveBench Coding—69.7%
MirrorCode10%—
CadEval—56%
ALE-Bench1,943—
HumanEval+—89%
MBPP+—80.2%

Agentic & Tool Use GPT-5.5 leads

GPT-5.5: 50.7 (#6), o1: 24.6 (#117)

Agentic & Tool Use benchmarks
BenchmarkGPT-5.5o1
Terminal-Bench84.7%—
APEX-Agents55.1%—
OSWorld 2.013%—
Remote Labor Index6.3%—
τ²-bench Banking44.6%—
Cybench—10%
DeepResearch Bench54%—
PostTrainBench27.2%—
ExploitBench47.4%—
GBAEval53.2%—
GDP.pdf26%—
LMArena Search1242—
METR Time Horizons—51.1%
Vending-Bench 27,524—

Reasoning GPT-5.5 leads

GPT-5.5: 72.8 (#11), o1: 27.9 (#111)

Math GPT-5.5 leads

GPT-5.5: 81.7 (#11), o1: 36.1 (#175)

Knowledge GPT-5.5 leads

GPT-5.5: 64.4 (#17), o1: 41.5 (#110)

Knowledge benchmarks
BenchmarkGPT-5.5o1
GPQA Diamond94%76.8%
SimpleQA Verified63%41.1%
LMArena Expert15081361
Humanity's Last Exam—8%
Confabulations—11.7%
Vectara Hallucination Rate9.3%—

Multimodal GPT-5.5 leads

GPT-5.5: 46.9 (#12), o1: 34.2 (#93)

Multimodal benchmarks
BenchmarkGPT-5.5o1
LMArena Vision12971168
GeoBench—80%
VPCT—37%
Blueprint-Bench 236.2%—
Furniture Assembly44.2%—
LMArena Document1486—
SpatialViz-Bench—41.4%

Multilingual GPT-5.5 leads

GPT-5.5: 56.4 (#20), o1: 48.6 (#142)

Multilingual benchmarks
BenchmarkGPT-5.5o1
LMArena Non-English14671358
LMArena Chinese15331394
LMArena French14861344
LMArena German14801337
LMArena Japanese14981346
LMArena Korean14601396
LMArena Russian14731356
LMArena Spanish14681345

Instruction Following GPT-5.5 leads

GPT-5.5: 77.5 (#18), o1: 74.8 (#86)

Instruction Following benchmarks
BenchmarkGPT-5.5o1
LMArena Instruction Following14791367
LiveBench Instruction Following—81.5%

Long Context o1 leads

GPT-5.5: 48.3 (#12), o1: 50.3 (#9)

Long Context benchmarks
BenchmarkGPT-5.5o1
LMArena Longer Query14841378
Fiction.LiveBench—83.3%
CL-bench Life22.2%—

Writing & Preference GPT-5.5 leads

GPT-5.5: 72.7 (#13), o1: 55.6 (#144)

Writing & Preference benchmarks
BenchmarkGPT-5.5o1
LMArena Text14721366
LMArena Creative Writing14551348
LMArena Multi-Turn14761369
Short-Story Creative Writing—70.2%
EQ-Bench Creative Writing1844—
EQ-Bench 41315—
LiveBench Language—65.4%

Frequently asked questions

Is GPT-5.5 better than o1?

GPT-5.5 is the stronger model overall, scoring 63.4 to 40.9 on the Noometry Index.

Which is cheaper, GPT-5.5 or o1?

GPT-5.5 is cheaper. It lists at $5 per million input tokens and $30 per million output tokens; o1 lists at $15 and $60.

Is GPT-5.5 or o1 better for coding?

GPT-5.5 scores higher on coding benchmarks: 58.2 versus 46.1 in the Noometry coding category.

Which has the bigger context window?

GPT-5.5 does, with 1.05M tokens against 200K.

How many benchmarks do GPT-5.5 and o1 share?

30 benchmarks have published results for both models. GPT-5.5 has 71 scored results on Noometry and o1 has 52.

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