Model comparison

Claude Opus 5 vs Grok 4.20 (Non-Reasoning)

Claude Opus 5 is the stronger model overall, scoring 67.7 to 48.5 on the Noometry Index. Grok 4.20 (Non-Reasoning) costs 6.4× less per token, which makes it the better buy when Claude Opus 5's lead doesn't matter for your workload.

Last verified . 39 shared benchmarks.

Claude Opus 5 Anthropic

67.7

Rank #4 Confirmed

Grok 4.20 (Non-Reasoning) xAI

48.5

Rank #48 Confirmed

Summary

  • They share 39 benchmarks with published results for both. Claude Opus 5 scores higher in 10 categories and Grok 4.20 (Non-Reasoning) in 0 categories; 10 gaps are clear of the uncertainty.
  • The widest gap is in math, where Claude Opus 5 leads 86.1 to 48.0.
  • The biggest single-benchmark swing is ProofBench: 99% for Claude Opus 5 and 14% for Grok 4.20 (Non-Reasoning).
  • Grok 4.20 (Non-Reasoning) is cheaper at $1.25 / $2.50 per million input/output tokens, against $5 / $25 for Claude Opus 5.

Side by side

Claude Opus 5 and Grok 4.20 (Non-Reasoning) specifications
Claude Opus 5Grok 4.20 (Non-Reasoning)
ProviderAnthropicxAI
Noometry Index67.748.5
Released2026-07-242026-02-17
WeightsProprietaryProprietary
Context window1M1M
Max output128K30K
Input $ / M tokens$5$1.25
Output $ / M tokens$25$2.50
Results tracked5746

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Category by category

Coding Claude Opus 5 leads

Claude Opus 5: 67.0 (#5), Grok 4.20 (Non-Reasoning): 41.8 (#104)

Coding benchmarks
BenchmarkClaude Opus 5Grok 4.20 (Non-Reasoning)
LMArena WebDev16941374
WeirdML91.8%52.3%
LMArena Coding15331458
ALE-Bench2,1651,150
DeepSWE73.6%—
FrontierCode53.4%—
CursorBench46.6%—
FrontierSWE52%—
SciCode56.4%—

Agentic & Tool Use Claude Opus 5 leads

Claude Opus 5: 55.5 (#1), Grok 4.20 (Non-Reasoning): 34.3 (#43)

Agentic & Tool Use benchmarks
BenchmarkClaude Opus 5Grok 4.20 (Non-Reasoning)
τ²-bench Banking48.7%18%
Vending-Bench 211,1824,663
Terminal-Bench—57.3%
APEX-Agents65.8%—
OSWorld 2.031.4%—
PostTrainBench35%—
BALROG63.4%—
GBAEval79.6%—
GDP.pdf24%—
LMArena Search—1189

Reasoning Claude Opus 5 leads

Claude Opus 5: 77.1 (#3), Grok 4.20 (Non-Reasoning): 52.2 (#30)

Reasoning benchmarks
BenchmarkClaude Opus 5Grok 4.20 (Non-Reasoning)
ARC-AGI-290.4%65.1%
NYT Connections (extended)94.3%85.4%
ARC-AGI-197.5%89.5%
Chess Puzzles42%24%
LMArena Hard Prompts15251451
DTBench97.9%90.1%
LMCA64.5%38.7%
Epoch Capabilities Index162.67152.01
SimpleBench80.6%—
Kagi LLM Benchmark—75%
CritPt29.1%—
Thematic Generalization—63.8%
EBR-Bench45.7%—
Mystery Game Puzzles59%—
Bench to the Future 30.12—
ForecastBench—61.4

Math Claude Opus 5 leads

Claude Opus 5: 86.1 (#6), Grok 4.20 (Non-Reasoning): 48.0 (#54)

Math benchmarks
BenchmarkClaude Opus 5Grok 4.20 (Non-Reasoning)
FrontierMath (Tiers 1-3)85.6%44.9%
FrontierMath Tier 473.2%17.1%
OTIS Mock AIME 2024-202598.9%92.2%
ProofBench99%14%
LMArena Math15331455

Knowledge Claude Opus 5 leads

Claude Opus 5: 66.8 (#8), Grok 4.20 (Non-Reasoning): 52.8 (#54)

Knowledge benchmarks
BenchmarkClaude Opus 5Grok 4.20 (Non-Reasoning)
GPQA Diamond93.9%89.3%
SimpleQA Verified59.9%30.2%
LMArena Expert15581440

Multimodal Claude Opus 5 leads

Claude Opus 5: 51.1 (#6), Grok 4.20 (Non-Reasoning): 33.2 (#88)

Multimodal benchmarks
BenchmarkClaude Opus 5Grok 4.20 (Non-Reasoning)
LMArena Vision13211263
Blueprint-Bench 230.4%0%
LMArena Document15161416
Furniture Assembly60.8%—

Multilingual Claude Opus 5 leads

Claude Opus 5: 58.8 (#3), Grok 4.20 (Non-Reasoning): 54.7 (#38)

Multilingual benchmarks
BenchmarkClaude Opus 5Grok 4.20 (Non-Reasoning)
LMArena Non-English15001440
LMArena Chinese15751481
LMArena French15221477
LMArena German15221463
LMArena Japanese15101450
LMArena Korean15261417
LMArena Russian15071457
LMArena Spanish15191442

Instruction Following Claude Opus 5 leads

Claude Opus 5: 79.3 (#5), Grok 4.20 (Non-Reasoning): 75.0 (#79)

Instruction Following benchmarks
BenchmarkClaude Opus 5Grok 4.20 (Non-Reasoning)
LMArena Instruction Following15161420

Long Context Claude Opus 5 leads

Claude Opus 5: 46.5 (#20), Grok 4.20 (Non-Reasoning): 45.4 (#33)

Long Context benchmarks
BenchmarkClaude Opus 5Grok 4.20 (Non-Reasoning)
LMArena Longer Query15161436
CL-bench—22.2%
CL-bench Life—11.9%

Writing & Preference Claude Opus 5 leads

Claude Opus 5: 79.3 (#2), Grok 4.20 (Non-Reasoning): 65.9 (#42)

Writing & Preference benchmarks
BenchmarkClaude Opus 5Grok 4.20 (Non-Reasoning)
LMArena Text15061451
LMArena Creative Writing14911439
EQ-Bench Creative Writing21331574
LMArena Multi-Turn14961456
EQ-Bench 41385—

Frequently asked questions

Is Claude Opus 5 better than Grok 4.20 (Non-Reasoning)?

Claude Opus 5 is the stronger model overall, scoring 67.7 to 48.5 on the Noometry Index. Grok 4.20 (Non-Reasoning) costs 6.4× less per token, which makes it the better buy when Claude Opus 5's lead doesn't matter for your workload.

Which is cheaper, Claude Opus 5 or Grok 4.20 (Non-Reasoning)?

Grok 4.20 (Non-Reasoning) is cheaper. It lists at $1.25 per million input tokens and $2.50 per million output tokens; Claude Opus 5 lists at $5 and $25.

Is Claude Opus 5 or Grok 4.20 (Non-Reasoning) better for coding?

Claude Opus 5 scores higher on coding benchmarks: 67.0 versus 41.8 in the Noometry coding category.

Which has the bigger context window?

Both accept 1M tokens.

How many benchmarks do Claude Opus 5 and Grok 4.20 (Non-Reasoning) share?

39 benchmarks have published results for both models. Claude Opus 5 has 57 scored results on Noometry and Grok 4.20 (Non-Reasoning) has 46.

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