Model comparison

Grok 4.5 vs o3

Grok 4.5 is the stronger model overall, scoring 55.0 to 47.5 on the Noometry Index.

Last verified . 35 shared benchmarks.

Grok 4.5 xAI

55.0

Rank #25 Confirmed

o3 OpenAI

47.5

Rank #61 Confirmed

Summary

  • They share 35 benchmarks with published results for both. Grok 4.5 scores higher in 8 categories and o3 in 2 categories; 10 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Grok 4.5 leads 56.1 to 32.0.
  • The biggest single-benchmark swing is ARC-AGI-2: 52.6% for Grok 4.5 and 6.5% for o3.
  • Grok 4.5 is cheaper at $2 / $6 per million input/output tokens, against $2 / $8 for o3.
  • Grok 4.5 accepts more context: 500K tokens versus 200K.

Side by side

Grok 4.5 and o3 specifications
Grok 4.5o3
ProviderxAIOpenAI
Noometry Index55.047.5
Released2026-07-082025-04-16
WeightsProprietaryProprietary
Context window500K200K
Max output500K100K
Input $ / M tokens$2$2
Output $ / M tokens$6$8
Results tracked5263

Sponsored placements are available on pages like this one. Advertise on Noometry

Category by category

Coding Grok 4.5 leads

Grok 4.5: 52.2 (#35), o3: 46.8 (#64)

Coding benchmarks
BenchmarkGrok 4.5o3
WeirdML46.4%52.4%
LMArena Coding14741408
ALE-Bench1,309933.55
SWE-bench Verified—62.3%
DeepSWE53.8%—
FrontierCode42.4%—
SWE-bench Verified (bash only)—58.4%
Aider Polyglot—81.3%
LMArena WebDev1553—
SciCode54.1%—
GSO—8.8%
CadEval—74%

Agentic & Tool Use Grok 4.5 leads

Grok 4.5: 44.4 (#17), o3: 34.5 (#44)

Agentic & Tool Use benchmarks
BenchmarkGrok 4.5o3
LMArena Search12131144
APEX-Agents56.2%—
Berkeley Function Calling Leaderboard—63%
GDPval—30.8%
τ²-bench Banking47.9%—
DeepResearch Bench—45.2%
OSWorld—23%
PostTrainBench23.4%—
GBAEval65.4%—
GDP.pdf14%—
METR Time Horizons—65.4%
Vending-Bench 23,887—

Reasoning Grok 4.5 leads

Grok 4.5: 56.1 (#25), o3: 32.0 (#78)

Reasoning benchmarks
BenchmarkGrok 4.5o3
ARC-AGI-252.6%6.5%
SimpleBench70%53.1%
Kagi LLM Benchmark83.5%67.6%
ARC-AGI-187.2%60.8%
CritPt15.4%1.4%
Chess Puzzles36%38%
LMArena Hard Prompts14621402
DTBench96.5%84.8%
LMCA45.2%39.7%
Epoch Capabilities Index153.92146.86
NYT Connections (extended)79.9%—
EnigmaEval—13.1%
Mystery Game Puzzles—29%
Surface Evolver Bench74.4%—
ForecastBench—62.5

Math Grok 4.5 leads

Grok 4.5: 60.9 (#35), o3: 50.2 (#58)

Knowledge Grok 4.5 leads

Grok 4.5: 62.3 (#24), o3: 54.6 (#52)

Knowledge benchmarks
BenchmarkGrok 4.5o3
GPQA Diamond93.4%81.8%
SimpleQA Verified48.3%49.4%
LMArena Expert14661402
Humanity's Last Exam—20.3%
MMLU-Pro—85.9%
Confabulations—14.4%
GPQA (HELM)—75.3%

Multimodal o3 leads

Grok 4.5: 37.6 (#72), o3: 41.4 (#36)

Multimodal benchmarks
BenchmarkGrok 4.5o3
LMArena Vision12881214
GeoBench—74%
VPCT—52%
Blueprint-Bench 227.3%—
Furniture Assembly22.5%—
LMArena Document1452—

Multilingual Grok 4.5 leads

Grok 4.5: 54.4 (#42), o3: 51.7 (#105)

Multilingual benchmarks
BenchmarkGrok 4.5o3
LMArena Non-English14401401
LMArena Chinese14961437
LMArena French14561430
LMArena German14461420
LMArena Japanese14281403
LMArena Korean14041370
LMArena Russian14481406
LMArena Spanish14501395

Instruction Following Grok 4.5 leads

Grok 4.5: 76.0 (#48), o3: 72.8 (#127)

Instruction Following benchmarks
BenchmarkGrok 4.5o3
LMArena Instruction Following14461368
IFEval—86.9%

Long Context o3 leads

Grok 4.5: 44.8 (#56), o3: 53.3 (#6)

Long Context benchmarks
BenchmarkGrok 4.5o3
LMArena Longer Query14631372
Fiction.LiveBench—88.9%
CL-bench—17.8%

Writing & Preference Grok 4.5 leads

Grok 4.5: 65.8 (#42), o3: 63.5 (#64)

Writing & Preference benchmarks
BenchmarkGrok 4.5o3
LMArena Text14481410
LMArena Creative Writing14421359
EQ-Bench Creative Writing15791676
LMArena Multi-Turn14561405
Short-Story Creative Writing—83.9%
WildBench—86.1%

Frequently asked questions

Is Grok 4.5 better than o3?

Grok 4.5 is the stronger model overall, scoring 55.0 to 47.5 on the Noometry Index.

Which is cheaper, Grok 4.5 or o3?

Grok 4.5 is cheaper. It lists at $2 per million input tokens and $6 per million output tokens; o3 lists at $2 and $8.

Is Grok 4.5 or o3 better for coding?

Grok 4.5 scores higher on coding benchmarks: 52.2 versus 46.8 in the Noometry coding category.

Which has the bigger context window?

Grok 4.5 does, with 500K tokens against 200K.

How many benchmarks do Grok 4.5 and o3 share?

35 benchmarks have published results for both models. Grok 4.5 has 52 scored results on Noometry and o3 has 63.

Related comparisons

Go deeper