Model comparison

GPT-5 Nano vs Grok 4.20 Multi-Agent

Grok 4.20 Multi-Agent is the stronger model overall, scoring 45.5 to 33.4 on the Noometry Index. GPT-5 Nano costs 11× less per token, which makes it the better buy when Grok 4.20 Multi-Agent's lead doesn't matter for your workload.

Last verified . 16 shared benchmarks.

GPT-5 Nano OpenAI

33.4

Rank #234 Confirmed

Grok 4.20 Multi-Agent xAI

45.5

Rank #62 Confirmed

Summary

  • They share 16 benchmarks with published results for both. GPT-5 Nano scores higher in 1 category and Grok 4.20 Multi-Agent in 8 categories; 8 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Grok 4.20 Multi-Agent leads 42.4 to 16.4.
  • GPT-5 Nano is cheaper at $0.05 / $0.40 per million input/output tokens, against $1.25 / $2.50 for Grok 4.20 Multi-Agent.
  • Grok 4.20 Multi-Agent accepts more context: 1M tokens versus 400K.

Side by side

GPT-5 Nano and Grok 4.20 Multi-Agent specifications
GPT-5 NanoGrok 4.20 Multi-Agent
ProviderOpenAIxAI
Noometry Index33.445.5
Released2025-08-072026-03-09
WeightsProprietaryProprietary
Context window400K1M
Max output128K30K
Input $ / M tokens$0.05$1.25
Output $ / M tokens$0.40$2.50
Results tracked4820

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Category by category

Coding Grok 4.20 Multi-Agent leads

GPT-5 Nano: 33.3 (#248), Grok 4.20 Multi-Agent: 42.4 (#91)

Coding benchmarks
BenchmarkGPT-5 NanoGrok 4.20 Multi-Agent
LMArena Coding13511458
SWE-bench Verified (bash only)34.8%—
WeirdML38.1%—
ALE-Bench718.67—

Agentic & Tool Use Not comparable

GPT-5 Nano: 25.6 (#99), Grok 4.20 Multi-Agent: —

Agentic & Tool Use benchmarks
BenchmarkGPT-5 NanoGrok 4.20 Multi-Agent
Terminal-Bench21.8%—
Berkeley Function Calling Leaderboard51.5%—
LMArena Search—1204

Reasoning Grok 4.20 Multi-Agent leads

GPT-5 Nano: 16.4 (#291), Grok 4.20 Multi-Agent: 42.4 (#44)

Reasoning benchmarks
BenchmarkGPT-5 NanoGrok 4.20 Multi-Agent
LMArena Hard Prompts13291448
ARC-AGI-22.6%—
Kagi LLM Benchmark62.2%—
NYT Connections (extended)—89.6%
ARC-AGI-120.7%—
Chess Puzzles27%—
Mystery Game Puzzles9%—
DTBench62.7%—
LMCA7.9%—
Epoch Capabilities Index139.39—
ForecastBench59.1—

Math Grok 4.20 Multi-Agent leads

GPT-5 Nano: 29.1 (#221), Grok 4.20 Multi-Agent: 36.6 (#106)

Math benchmarks
BenchmarkGPT-5 NanoGrok 4.20 Multi-Agent
LMArena Math13181441
FrontierMath (Tiers 1-3)20%—
FrontierMath Tier 42.4%—
OTIS Mock AIME 2024-202581.1%—
ProofBench12%—
Omni-MATH54.6%—
MATH Level 595.2%—
FrontierMath (Feb 2025 set)8.3%—
FrontierMath Tier 4 (v1)2.1%—

Knowledge Grok 4.20 Multi-Agent leads

GPT-5 Nano: 35.8 (#166), Grok 4.20 Multi-Agent: 39.7 (#116)

Knowledge benchmarks
BenchmarkGPT-5 NanoGrok 4.20 Multi-Agent
LMArena Expert13211445
GPQA Diamond69.4%—
SimpleQA Verified11.7%—
MMLU-Pro77.8%—
Vectara Hallucination Rate10.5%—
GPQA (HELM)67.9%—

Multimodal Grok 4.20 Multi-Agent leads

GPT-5 Nano: 30.7 (#102), Grok 4.20 Multi-Agent: 39.8 (#44)

Multimodal benchmarks
BenchmarkGPT-5 NanoGrok 4.20 Multi-Agent
LMArena Vision11591259
VPCT37.2%—

Multilingual Grok 4.20 Multi-Agent leads

GPT-5 Nano: 45.5 (#167), Grok 4.20 Multi-Agent: 54.6 (#40)

Multilingual benchmarks
BenchmarkGPT-5 NanoGrok 4.20 Multi-Agent
LMArena Non-English13131440
LMArena Chinese13551475
LMArena German13291456
LMArena Korean12691416
LMArena Russian12961457
LMArena Spanish13601447
LMArena French—1467
LMArena Japanese—1405

Instruction Following Too close to call

GPT-5 Nano: 75.2 (#72), Grok 4.20 Multi-Agent: 75.0 (#80)

Instruction Following benchmarks
BenchmarkGPT-5 NanoGrok 4.20 Multi-Agent
LMArena Instruction Following13061420
IFEval93.2%—

Long Context Grok 4.20 Multi-Agent leads

GPT-5 Nano: 31.3 (#275), Grok 4.20 Multi-Agent: 43.7 (#84)

Long Context benchmarks
BenchmarkGPT-5 NanoGrok 4.20 Multi-Agent
LMArena Longer Query13131430
Fiction.LiveBench44.4%—

Writing & Preference Grok 4.20 Multi-Agent leads

GPT-5 Nano: 39.4 (#244), Grok 4.20 Multi-Agent: 64.1 (#57)

Writing & Preference benchmarks
BenchmarkGPT-5 NanoGrok 4.20 Multi-Agent
LMArena Text13201450
LMArena Creative Writing12501435
LMArena Multi-Turn13111451
EQ-Bench Creative Writing705—
WildBench80.6%—

Frequently asked questions

Is GPT-5 Nano better than Grok 4.20 Multi-Agent?

Grok 4.20 Multi-Agent is the stronger model overall, scoring 45.5 to 33.4 on the Noometry Index. GPT-5 Nano costs 11× less per token, which makes it the better buy when Grok 4.20 Multi-Agent's lead doesn't matter for your workload.

Which is cheaper, GPT-5 Nano or Grok 4.20 Multi-Agent?

GPT-5 Nano is cheaper. It lists at $0.05 per million input tokens and $0.40 per million output tokens; Grok 4.20 Multi-Agent lists at $1.25 and $2.50.

Is GPT-5 Nano or Grok 4.20 Multi-Agent better for coding?

Grok 4.20 Multi-Agent scores higher on coding benchmarks: 42.4 versus 33.3 in the Noometry coding category.

Which has the bigger context window?

Grok 4.20 Multi-Agent does, with 1M tokens against 400K.

How many benchmarks do GPT-5 Nano and Grok 4.20 Multi-Agent share?

16 benchmarks have published results for both models. GPT-5 Nano has 48 scored results on Noometry and Grok 4.20 Multi-Agent has 20.

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