Noometry

Model comparison

Claude Sonnet 5 vs Grok 4.3

Claude Sonnet 5 is the stronger model overall, scoring 54.6 to 43.8 on the Noometry Index. Grok 4.3 costs 2.6× less per token, which makes it the better buy when Claude Sonnet 5's lead doesn't matter for your workload.

Last verified . 39 shared benchmarks.

Claude Sonnet 5 Anthropic

54.6

Rank #29 Confirmed

Grok 4.3 xAI

43.8

Rank #86 Confirmed

Summary

  • They share 39 benchmarks with published results for both. Claude Sonnet 5 scores higher in 10 categories and Grok 4.3 in 0 categories; 10 gaps are clear of the uncertainty.
  • The widest gap is in math, where Claude Sonnet 5 leads 66.2 to 46.0.
  • The biggest single-benchmark swing is ProofBench: 77% for Claude Sonnet 5 and 11% for Grok 4.3.
  • Grok 4.3 is cheaper at $1.25 / $2.50 per million input/output tokens, against $2 / $10 for Claude Sonnet 5.

Side by side

Claude Sonnet 5Grok 4.3
ProviderAnthropicxAI
Noometry Index54.643.8
Released2026-06-292026-04-17
WeightsProprietaryProprietary
Context window1M1M
Max output128K30K
Input $ / M tokens$2$1.25
Output $ / M tokens$10$2.50
Results tracked5140

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Category by category

Coding Claude Sonnet 5 leads

Claude Sonnet 5: 55.5 (#26), Grok 4.3: 41.6 (#121)

BenchmarkClaude Sonnet 5Grok 4.3
LMArena WebDev15411357
SciCode54.3%47.3%
WeirdML68.8%49.9%
LMArena Coding14831415
ALE-Bench1,463944.17
DeepSWE53.8%—
FrontierCode42.7%—
CursorBench34.1%—
GSO37.3%—

Agentic & Tool Use Claude Sonnet 5 leads

Claude Sonnet 5: 42.8 (#18), Grok 4.3: 27.7 (#99)

BenchmarkClaude Sonnet 5Grok 4.3
LMArena Search11941165
Vending-Bench 26,37835.26
APEX-Agents54.5%—
GBAEval65.3%—
GDP.pdf—8%

Reasoning Claude Sonnet 5 leads

Claude Sonnet 5: 49.1 (#39), Grok 4.3: 35.9 (#68)

BenchmarkClaude Sonnet 5Grok 4.3
NYT Connections (extended)75.1%55.2%
CritPt16.9%8%
Chess Puzzles35%25%
LMArena Hard Prompts14611396
DTBench92.5%90.7%
LMCA50%38.3%
Epoch Capabilities Index156.21149.16
ForecastBench61.160.3
SimpleBench60.6%—
Mystery Game Puzzles35%—
Surface Evolver Bench60%—
Bench to the Future 30.14—

Math Claude Sonnet 5 leads

Claude Sonnet 5: 66.2 (#27), Grok 4.3: 46.0 (#74)

BenchmarkClaude Sonnet 5Grok 4.3
FrontierMath (Tiers 1-3)65.6%42.8%
FrontierMath Tier 429.3%14.6%
OTIS Mock AIME 2024-202594.7%93.3%
ProofBench77%11%
LMArena Math14671388

Knowledge Claude Sonnet 5 leads

Claude Sonnet 5: 55.6 (#47), Grok 4.3: 52.5 (#62)

BenchmarkClaude Sonnet 5Grok 4.3
GPQA Diamond90.5%88.8%
SimpleQA Verified33.7%33.2%
LMArena Expert14901385

Multimodal Claude Sonnet 5 leads

Claude Sonnet 5: 42.4 (#31), Grok 4.3: 31.6 (#104)

BenchmarkClaude Sonnet 5Grok 4.3
LMArena Vision12741229
Blueprint-Bench 224.9%0%
LMArena Document1466—

Multilingual Claude Sonnet 5 leads

Claude Sonnet 5: 53.8 (#55), Grok 4.3: 50.5 (#120)

BenchmarkClaude Sonnet 5Grok 4.3
LMArena Non-English14311385
LMArena Chinese14771422
LMArena French14601412
LMArena German14401395
LMArena Japanese14221379
LMArena Korean14111356
LMArena Russian14511399
LMArena Spanish14371398

Instruction Following Claude Sonnet 5 leads

Claude Sonnet 5: 76.3 (#41), Grok 4.3: 72.1 (#140)

BenchmarkClaude Sonnet 5Grok 4.3
LMArena Instruction Following14521366

Long Context Claude Sonnet 5 leads

Claude Sonnet 5: 44.8 (#55), Grok 4.3: 42.5 (#123)

BenchmarkClaude Sonnet 5Grok 4.3
LMArena Longer Query14631393

Writing & Preference Claude Sonnet 5 leads

Claude Sonnet 5: 69.2 (#25), Grok 4.3: 58.5 (#118)

BenchmarkClaude Sonnet 5Grok 4.3
LMArena Text14421397
LMArena Creative Writing14161380
EQ-Bench 412361075
LMArena Multi-Turn14541406
EQ-Bench Creative Writing1794—

Frequently asked questions

Is Claude Sonnet 5 better than Grok 4.3?

Claude Sonnet 5 is the stronger model overall, scoring 54.6 to 43.8 on the Noometry Index. Grok 4.3 costs 2.6× less per token, which makes it the better buy when Claude Sonnet 5's lead doesn't matter for your workload.

Which is cheaper, Claude Sonnet 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 Sonnet 5 lists at $2 and $10.

Is Claude Sonnet 5 or Grok 4.3 better for coding?

Claude Sonnet 5 scores higher on coding benchmarks: 55.5 versus 41.6 in the Noometry coding category.

Which has the bigger context window?

Both accept 1M tokens.

How many benchmarks do Claude Sonnet 5 and Grok 4.3 share?

39 benchmarks have published results for both models. Claude Sonnet 5 has 51 scored results on Noometry and Grok 4.3 has 40.

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