Model comparison

Claude Opus 4.5 vs Grok 4.3

Claude Opus 4.5 is the stronger model overall, scoring 50.5 to 43.6 on the Noometry Index. Grok 4.3 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 . 34 shared benchmarks.

Claude Opus 4.5 Anthropic

50.5

Rank #39 Confirmed

Grok 4.3 xAI

43.6

Rank #80 Confirmed

Summary

  • They share 34 benchmarks with published results for both. Claude Opus 4.5 scores higher in 8 categories and Grok 4.3 in 2 categories; 9 gaps are clear of the uncertainty.
  • The widest gap is in agentic & tool use, where Claude Opus 4.5 leads 47.2 to 27.6.
  • The biggest single-benchmark swing is ProofBench: 36% for Claude Opus 4.5 and 11% for Grok 4.3.
  • Grok 4.3 is cheaper at $1.25 / $2.50 per million input/output tokens, against $5 / $25 for Claude Opus 4.5.
  • Grok 4.3 accepts more context: 1M tokens versus 200K.

Side by side

Claude Opus 4.5 and Grok 4.3 specifications
Claude Opus 4.5Grok 4.3
ProviderAnthropicxAI
Noometry Index50.543.6
Released2025-11-012026-04-17
WeightsProprietaryProprietary
Context window200K1M
Max output64K30K
Input $ / M tokens$5$1.25
Output $ / M tokens$25$2.50
Results tracked6940

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Category by category

Coding Claude Opus 4.5 leads

Claude Opus 4.5: 55.4 (#21), Grok 4.3: 41.3 (#117)

Coding benchmarks
BenchmarkClaude Opus 4.5Grok 4.3
LMArena WebDev14931357
WeirdML63.7%49.9%
LMArena Coding15041415
ALE-Bench1,025944.17
SWE-bench Verified76.7%—
SWE-bench Verified (bash only)76.8%—
SWE-bench Multilingual70.7%—
SciCode—47.3%
GSO26.5%—
AlgoTune1.77—

Agentic & Tool Use Claude Opus 4.5 leads

Claude Opus 4.5: 47.2 (#11), Grok 4.3: 27.6 (#93)

Agentic & Tool Use benchmarks
BenchmarkClaude Opus 4.5Grok 4.3
LMArena Search11801165
Vending-Bench 24,96735.26
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%—
GDP.pdf—8%
METR Time Horizons75%—

Reasoning Claude Opus 4.5 leads

Claude Opus 4.5: 42.5 (#43), Grok 4.3: 34.9 (#60)

Reasoning benchmarks
BenchmarkClaude Opus 4.5Grok 4.3
NYT Connections (extended)52.5%55.2%
Chess Puzzles12%25%
LMArena Hard Prompts14761397
DTBench89.9%90.7%
LMCA44.5%38.3%
Epoch Capabilities Index150.1149.13
ForecastBench60.760.3
ARC-AGI-237.6%—
SimpleBench62%—
Kagi LLM Benchmark80.2%—
ARC-AGI-180%—
CritPt—8%
EnigmaEval11.9%—
EBR-Bench14.3%—
Mystery Game Puzzles22%—

Math Grok 4.3 leads

Claude Opus 4.5: 38.5 (#85), Grok 4.3: 45.8 (#60)

Math benchmarks
BenchmarkClaude Opus 4.5Grok 4.3
FrontierMath (Tiers 1-3)34.4%42.8%
FrontierMath Tier 44.9%14.6%
OTIS Mock AIME 2024-202586.1%93.3%
ProofBench36%11%
LMArena Math14631388
FrontierMath (Feb 2025 set)20.7%—
FrontierMath Tier 4 (v1)4.2%—

Knowledge Claude Opus 4.5 leads

Claude Opus 4.5: 56.4 (#38), Grok 4.3: 52.5 (#57)

Knowledge benchmarks
BenchmarkClaude Opus 4.5Grok 4.3
GPQA Diamond86%88.8%
SimpleQA Verified45.7%33.2%
LMArena Expert14881385
Humanity's Last Exam25.2%—
Vectara Hallucination Rate10.9%—

Multimodal Too close to call

Claude Opus 4.5: 31.1 (#99), Grok 4.3: 31.6 (#96)

Multimodal benchmarks
BenchmarkClaude Opus 4.5Grok 4.3
LMArena Vision—1231
GeoBench75%—
VPCT40%—
Blueprint-Bench 2—0%
Furniture Assembly28.3%—
LMArena Document1462—

Multilingual Claude Opus 4.5 leads

Claude Opus 4.5: 54.5 (#45), Grok 4.3: 50.7 (#114)

Multilingual benchmarks
BenchmarkClaude Opus 4.5Grok 4.3
LMArena Non-English14381385
LMArena Chinese14701423
LMArena French14711412
LMArena German14491395
LMArena Japanese14151379
LMArena Korean14241357
LMArena Russian14481399
LMArena Spanish14551402

Instruction Following Claude Opus 4.5 leads

Claude Opus 4.5: 77.7 (#20), Grok 4.3: 72.3 (#135)

Instruction Following benchmarks
BenchmarkClaude Opus 4.5Grok 4.3
LMArena Instruction Following14781366

Long Context Claude Opus 4.5 leads

Claude Opus 4.5: 46.4 (#21), Grok 4.3: 42.5 (#118)

Long Context benchmarks
BenchmarkClaude Opus 4.5Grok 4.3
LMArena Longer Query14801393
CL-bench21.1%—

Writing & Preference Claude Opus 4.5 leads

Claude Opus 4.5: 68.2 (#28), Grok 4.3: 58.6 (#112)

Writing & Preference benchmarks
BenchmarkClaude Opus 4.5Grok 4.3
LMArena Text14511397
LMArena Creative Writing14451380
LMArena Multi-Turn14661406
EQ-Bench Creative Writing1687—
EQ-Bench 4—1075

Frequently asked questions

Is Claude Opus 4.5 better than Grok 4.3?

Claude Opus 4.5 is the stronger model overall, scoring 50.5 to 43.6 on the Noometry Index. Grok 4.3 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 4.3?

Grok 4.3 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 4.3 better for coding?

Claude Opus 4.5 scores higher on coding benchmarks: 55.4 versus 41.3 in the Noometry coding category.

Which has the bigger context window?

Grok 4.3 does, with 1M tokens against 200K.

How many benchmarks do Claude Opus 4.5 and Grok 4.3 share?

34 benchmarks have published results for both models. Claude Opus 4.5 has 69 scored results on Noometry and Grok 4.3 has 40.

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