Model comparison

Claude Opus 4.8 vs Grok 4.20 Multi-Agent

Claude Opus 4.8 is the stronger model overall, scoring 60.7 to 45.5 on the Noometry Index. Grok 4.20 Multi-Agent costs 6.4× less per token, which makes it the better buy when Claude Opus 4.8's lead doesn't matter for your workload.

Last verified . 20 shared benchmarks.

Claude Opus 4.8 Anthropic

60.7

Rank #9 Confirmed

Grok 4.20 Multi-Agent xAI

45.5

Rank #62 Confirmed

Summary

  • They share 20 benchmarks with published results for both. Claude Opus 4.8 scores higher in 9 categories and Grok 4.20 Multi-Agent in 0 categories; 8 gaps are clear of the uncertainty.
  • The widest gap is in math, where Claude Opus 4.8 leads 78.2 to 36.6.
  • Grok 4.20 Multi-Agent is cheaper at $1.25 / $2.50 per million input/output tokens, against $5 / $25 for Claude Opus 4.8.

Side by side

Claude Opus 4.8 and Grok 4.20 Multi-Agent specifications
Claude Opus 4.8Grok 4.20 Multi-Agent
ProviderAnthropicxAI
Noometry Index60.745.5
Released2026-05-282026-03-09
WeightsProprietaryProprietary
Context window1M1M
Max output128K30K
Input $ / M tokens$5$1.25
Output $ / M tokens$25$2.50
Results tracked6520

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Category by category

Coding Claude Opus 4.8 leads

Claude Opus 4.8: 60.2 (#9), Grok 4.20 Multi-Agent: 42.4 (#91)

Coding benchmarks
BenchmarkClaude Opus 4.8Grok 4.20 Multi-Agent
LMArena Coding14911458
DeepSWE59%—
FrontierCode46.5%—
LMArena WebDev1556—
SciCode53.5%—
GSO47.1%—
WeirdML82.9%—
ALE-Bench1,564—

Agentic & Tool Use Not comparable

Claude Opus 4.8: 47.6 (#10), Grok 4.20 Multi-Agent: —

Agentic & Tool Use benchmarks
BenchmarkClaude Opus 4.8Grok 4.20 Multi-Agent
LMArena Search12041204
APEX-Agents48.9%—
OSWorld 2.020.6%—
Remote Labor Index8.3%—
τ²-bench Banking39.7%—
DeepResearch Bench50.2%—
PostTrainBench33.8%—
GBAEval70.9%—
GDP.pdf24%—
Vending-Bench 25,787—

Reasoning Claude Opus 4.8 leads

Claude Opus 4.8: 64.6 (#14), Grok 4.20 Multi-Agent: 42.4 (#44)

Reasoning benchmarks
BenchmarkClaude Opus 4.8Grok 4.20 Multi-Agent
NYT Connections (extended)91.1%89.6%
LMArena Hard Prompts14811448
ARC-AGI-272.1%—
SimpleBench64.8%—
Kagi LLM Benchmark88.8%—
ARC-AGI-192.5%—
CritPt20.9%—
Chess Puzzles34%—
EnigmaEval23.5%—
EBR-Bench28.6%—
Mystery Game Puzzles36%—
DTBench94.9%—
LMCA57.5%—
Surface Evolver Bench87.5%—
Bench to the Future 30.14—
Epoch Capabilities Index158.3—
ForecastBench59.9—

Math Claude Opus 4.8 leads

Claude Opus 4.8: 78.2 (#11), Grok 4.20 Multi-Agent: 36.6 (#106)

Math benchmarks
BenchmarkClaude Opus 4.8Grok 4.20 Multi-Agent
LMArena Math14871441
FrontierMath (Tiers 1-3)80%—
FrontierMath Tier 456.1%—
MathArena Final-Answer Competitions91.8%—
OTIS Mock AIME 2024-202598.3%—
ProofBench69%—
FrontierMath (Feb 2025 set)47.2%—
FrontierMath Tier 4 (v1)31.3%—

Knowledge Claude Opus 4.8 leads

Claude Opus 4.8: 61.3 (#26), Grok 4.20 Multi-Agent: 39.7 (#116)

Knowledge benchmarks
BenchmarkClaude Opus 4.8Grok 4.20 Multi-Agent
LMArena Expert15011445
GPQA Diamond91%—
SimpleQA Verified53%—

Multimodal Claude Opus 4.8 leads

Claude Opus 4.8: 43.2 (#20), Grok 4.20 Multi-Agent: 39.8 (#44)

Multimodal benchmarks
BenchmarkClaude Opus 4.8Grok 4.20 Multi-Agent
LMArena Vision12951259
Blueprint-Bench 214.5%—
Furniture Assembly42.5%—
LMArena Document1475—

Multilingual Too close to call

Claude Opus 4.8: 55.4 (#31), Grok 4.20 Multi-Agent: 54.6 (#40)

Multilingual benchmarks
BenchmarkClaude Opus 4.8Grok 4.20 Multi-Agent
LMArena Non-English14501440
LMArena Chinese15091475
LMArena French14821467
LMArena German14701456
LMArena Japanese14401405
LMArena Korean14321416
LMArena Russian14761457
LMArena Spanish14701447

Instruction Following Claude Opus 4.8 leads

Claude Opus 4.8: 77.6 (#22), Grok 4.20 Multi-Agent: 75.0 (#80)

Instruction Following benchmarks
BenchmarkClaude Opus 4.8Grok 4.20 Multi-Agent
LMArena Instruction Following14761420

Long Context Claude Opus 4.8 leads

Claude Opus 4.8: 45.4 (#37), Grok 4.20 Multi-Agent: 43.7 (#84)

Long Context benchmarks
BenchmarkClaude Opus 4.8Grok 4.20 Multi-Agent
LMArena Longer Query14821430

Writing & Preference Claude Opus 4.8 leads

Claude Opus 4.8: 72.1 (#17), Grok 4.20 Multi-Agent: 64.1 (#57)

Writing & Preference benchmarks
BenchmarkClaude Opus 4.8Grok 4.20 Multi-Agent
LMArena Text14601450
LMArena Creative Writing14531435
LMArena Multi-Turn14761451
EQ-Bench Creative Writing1840—
EQ-Bench 41281—

Frequently asked questions

Is Claude Opus 4.8 better than Grok 4.20 Multi-Agent?

Claude Opus 4.8 is the stronger model overall, scoring 60.7 to 45.5 on the Noometry Index. Grok 4.20 Multi-Agent costs 6.4× less per token, which makes it the better buy when Claude Opus 4.8's lead doesn't matter for your workload.

Which is cheaper, Claude Opus 4.8 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 4.8 lists at $5 and $25.

Is Claude Opus 4.8 or Grok 4.20 Multi-Agent better for coding?

Claude Opus 4.8 scores higher on coding benchmarks: 60.2 versus 42.4 in the Noometry coding category.

Which has the bigger context window?

Both accept 1M tokens.

How many benchmarks do Claude Opus 4.8 and Grok 4.20 Multi-Agent share?

20 benchmarks have published results for both models. Claude Opus 4.8 has 65 scored results on Noometry and Grok 4.20 Multi-Agent has 20.

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