Noometry

Model comparison

Claude Opus 4.5 vs Grok 4.20 Multi-Agent

Claude Opus 4.5 is the stronger model overall, scoring 50.5 to 46.2 on the Noometry Index. Grok 4.20 Multi-Agent costs 6.4× less per token, which makes it the better buy when Claude Opus 4.5's lead doesn't matter for your workload.

Last verified . 19 shared benchmarks.

Claude Opus 4.5 Anthropic

50.5

Rank #47 Confirmed

Grok 4.20 Multi-Agent xAI

46.2

Rank #65 Confirmed

Summary

  • They share 19 benchmarks with published results for both. Claude Opus 4.5 scores higher in 5 categories and Grok 4.20 Multi-Agent in 4 categories; 7 gaps are clear of the uncertainty.
  • The widest gap is in knowledge, where Claude Opus 4.5 leads 56.5 to 40.4.
  • The biggest single-benchmark swing is NYT Connections (extended): 52.5% for Claude Opus 4.5 and 89.6% for Grok 4.20 Multi-Agent.
  • Grok 4.20 Multi-Agent is cheaper at $1.25 / $2.50 per million input/output tokens, against $5 / $25 for Claude Opus 4.5.
  • Grok 4.20 Multi-Agent accepts more context: 1M tokens versus 200K.

Side by side

Claude Opus 4.5Grok 4.20 Multi-Agent
ProviderAnthropicxAI
Noometry Index50.546.2
Released2025-11-012026-03-09
WeightsProprietaryProprietary
Context window200K1M
Max output64K30K
Input $ / M tokens$5$1.25
Output $ / M tokens$25$2.50
Results tracked6920

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Category by category

Coding Claude Opus 4.5 leads

Claude Opus 4.5: 54.8 (#27), Grok 4.20 Multi-Agent: 43.0 (#92)

BenchmarkClaude Opus 4.5Grok 4.20 Multi-Agent
LMArena Coding15041457
SWE-bench Verified76.7%—
SWE-bench Verified (bash only)76.8%—
LMArena WebDev1494—
SWE-bench Multilingual70.7%—
GSO26.5%—
WeirdML63.7%—
ALE-Bench1,025—
AlgoTune1.77—

Agentic & Tool Use Not comparable

Claude Opus 4.5: 47.3 (#12), Grok 4.20 Multi-Agent: —

BenchmarkClaude Opus 4.5Grok 4.20 Multi-Agent
LMArena Search11801204
Terminal-Bench63.1%—
Berkeley Function Calling Leaderboard77.5%—
GDPval45.5%—
Remote Labor Index3.8%—
τ²-bench Airline84%—
τ²-bench Banking24.7%—
τ²-bench Retail79.6%—
τ²-bench Telecom92.3%—
Cybench82%—
DeepResearch Bench54.8%—
OSWorld66.3%—
BALROG43.5%—
METR Time Horizons75%—
Vending-Bench 24,967—

Reasoning Grok 4.20 Multi-Agent leads

Claude Opus 4.5: 42.6 (#51), Grok 4.20 Multi-Agent: 43.9 (#48)

BenchmarkClaude Opus 4.5Grok 4.20 Multi-Agent
NYT Connections (extended)52.5%89.6%
LMArena Hard Prompts14761448
ARC-AGI-237.6%—
SimpleBench62%—
Kagi LLM Benchmark80.2%—
ARC-AGI-180%—
Chess Puzzles12%—
EnigmaEval11.9%—
EBR-Bench14.3%—
Mystery Game Puzzles22%—
DTBench89.9%—
LMCA44.5%—
Epoch Capabilities Index150.09—
ForecastBench60.7—

Math Too close to call

Claude Opus 4.5: 38.6 (#132), Grok 4.20 Multi-Agent: 39.4 (#104)

BenchmarkClaude Opus 4.5Grok 4.20 Multi-Agent
LMArena Math14631442
FrontierMath (Tiers 1-3)34.4%—
FrontierMath Tier 44.9%—
OTIS Mock AIME 2024-202586.1%—
ProofBench36%—
FrontierMath (Feb 2025 set)20.7%—
FrontierMath Tier 4 (v1)4.2%—

Knowledge Claude Opus 4.5 leads

Claude Opus 4.5: 56.5 (#44), Grok 4.20 Multi-Agent: 40.4 (#119)

BenchmarkClaude Opus 4.5Grok 4.20 Multi-Agent
LMArena Expert14871445
GPQA Diamond86%—
Humanity's Last Exam25.2%—
SimpleQA Verified45.7%—
Vectara Hallucination Rate10.9%—

Multimodal Grok 4.20 Multi-Agent leads

Claude Opus 4.5: 31.4 (#107), Grok 4.20 Multi-Agent: 40.5 (#48)

BenchmarkClaude Opus 4.5Grok 4.20 Multi-Agent
LMArena Vision—1259
GeoBench75%—
VPCT40%—
Furniture Assembly28.3%—
LMArena Document1462—

Multilingual Too close to call

Claude Opus 4.5: 54.3 (#47), Grok 4.20 Multi-Agent: 54.4 (#43)

BenchmarkClaude Opus 4.5Grok 4.20 Multi-Agent
LMArena Non-English14381440
LMArena Chinese14701475
LMArena French14711466
LMArena German14491456
LMArena Japanese14161405
LMArena Korean14241416
LMArena Russian14471457
LMArena Spanish14581447

Instruction Following Claude Opus 4.5 leads

Claude Opus 4.5: 77.5 (#19), Grok 4.20 Multi-Agent: 74.8 (#84)

BenchmarkClaude Opus 4.5Grok 4.20 Multi-Agent
LMArena Instruction Following14781420

Long Context Claude Opus 4.5 leads

Claude Opus 4.5: 46.5 (#22), Grok 4.20 Multi-Agent: 43.7 (#88)

BenchmarkClaude Opus 4.5Grok 4.20 Multi-Agent
LMArena Longer Query14801431
CL-bench21.1%—

Writing & Preference Claude Opus 4.5 leads

Claude Opus 4.5: 68.1 (#28), Grok 4.20 Multi-Agent: 64.0 (#59)

BenchmarkClaude Opus 4.5Grok 4.20 Multi-Agent
LMArena Text14511450
LMArena Creative Writing14451436
LMArena Multi-Turn14661452
EQ-Bench Creative Writing1687—

Frequently asked questions

Is Claude Opus 4.5 better than Grok 4.20 Multi-Agent?

Claude Opus 4.5 is the stronger model overall, scoring 50.5 to 46.2 on the Noometry Index. Grok 4.20 Multi-Agent costs 6.4× less per token, which makes it the better buy when Claude Opus 4.5's lead doesn't matter for your workload.

Which is cheaper, Claude Opus 4.5 or Grok 4.20 Multi-Agent?

Grok 4.20 Multi-Agent is cheaper. It lists at $1.25 per million input tokens and $2.50 per million output tokens; Claude Opus 4.5 lists at $5 and $25.

Is Claude Opus 4.5 or Grok 4.20 Multi-Agent better for coding?

Claude Opus 4.5 scores higher on coding benchmarks: 54.8 versus 43.0 in the Noometry coding category.

Which has the bigger context window?

Grok 4.20 Multi-Agent does, with 1M tokens against 200K.

How many benchmarks do Claude Opus 4.5 and Grok 4.20 Multi-Agent share?

19 benchmarks have published results for both models. Claude Opus 4.5 has 69 scored results on Noometry and Grok 4.20 Multi-Agent has 20.

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