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Model comparison

Claude Sonnet 5 vs Grok 4.20

Data verified

Head-to-head evidence from 6 shared benchmark results across 4 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

65.32/100
Margin
10.6pts
← winning
54.68/100
3 category wins0 category wins

Public leaderboard positions: Claude Sonnet 5 #29 (Estimated); Grok 4.20 #88 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. Claude Sonnet 5 and Grok 4.20 share 6 comparable benchmark results. 3 of 8 categories are comparable. 30 results are unique to Claude Sonnet 5; 12 to Grok 4.20.

Updated July 23, 2026
Shared results
6
Claude Sonnet 5 only
30
Grok 4.20 only
12
Comparable categories
3 / 8

Pick Claude Sonnet 5 if you want the stronger benchmark profile. Grok 4.20 only becomes the better choice if you want the cheaper token bill or you need the larger 2M context window.

Confidence note. This is a partial-evidence comparison with 6 shared benchmark results across 4 evidence categories; 3 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.

Why this result

Claude Sonnet 5 is clearly ahead on the BenchAlign aggregate, 65.32 to 54.68. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

Claude Sonnet 5's sharpest advantage is in agentic, where it averages 81.9 against 47.1. The single biggest benchmark swing on the page is Terminal-Bench 2.0, 80.4% to 47.1%.

Claude Sonnet 5 is also the more expensive model on tokens at $2.00 input / $10.00 output per 1M tokens, versus $2.00 input / $6.00 output per 1M tokens for Grok 4.20. Grok 4.20 gives you the larger context window at 2M, compared with 1M for Claude Sonnet 5.

Category breakdown

Exact category averages are shown below. Not measured means BenchLM does not have enough sourced public coverage for that model and category.

Category scores and score margins for Claude Sonnet 5 and Grok 4.20
CategoryClaude Sonnet 5ΔGrok 4.20
AgenticClaude Sonnet 581.9Margin← 34.8Grok 4.2047.1
MultimodalClaude Sonnet 588.3Margin← 18.2Grok 4.2070.1
CodingClaude Sonnet 576.7Margin← 9.6Grok 4.2067.1
ReasoningClaude Sonnet 5Not measuredMarginNo overlapGrok 4.2053.3
KnowledgeClaude Sonnet 557.4MarginNo overlapGrok 4.20Not measured

Decisive benchmark drivers

The largest measured benchmark gaps in this matchup, with exact reported values.

More
A · Claude Sonnet 5B · Grok 4.20

  1. Terminal-Bench 2.0

    Agentic
    Source ↗
    A 80.4%B 47.1%
    Winner: Claude Sonnet 5Δ 33.3
    Terminal-Bench 2.0: Claude Sonnet 5 scored 80.4%; Grok 4.20 scored 47.1%. Claude Sonnet 5 wins this benchmark.

  2. CharXiv

    Multimodal
    Source ↗
    A 88.3%B 60.9%
    Winner: Claude Sonnet 5Δ 27.4
    CharXiv: Claude Sonnet 5 scored 88.3%; Grok 4.20 scored 60.9%. Claude Sonnet 5 wins this benchmark.

  3. SWE-bench Pro

    Coding
    Source ↗
    A 63.2%B 51.8%
    Winner: Claude Sonnet 5Δ 11.4
    SWE-bench Pro: Claude Sonnet 5 scored 63.2%; Grok 4.20 scored 51.8%. Claude Sonnet 5 wins this benchmark.

  4. SWE-bench Verified

    Coding
    Source ↗
    A 85.2%B 76.7%
    Winner: Claude Sonnet 5Δ 8.5
    SWE-bench Verified: Claude Sonnet 5 scored 85.2%; Grok 4.20 scored 76.7%. Claude Sonnet 5 wins this benchmark.

Operational comparison

Runtime and commercial metrics are compared only when both models have a complete sourced value.

MetricClaude Sonnet 5Grok 4.20Comparison
Input / output priceUSD per 1M tokensClaude Sonnet 5$2 input / $10 outputGrok 4.20$2 input / $6 outputGrok 4.20 has the lower combined listed price.
Generation speedtokens per secondClaude Sonnet 5Not availableGrok 4.20233 tok/sA complete speed comparison is not available.
First-answer latencyseconds to first tokenClaude Sonnet 5Not availableGrok 4.2010.33 sA complete latency comparison is not available.
Context windowmaximum listed tokensClaude Sonnet 51MGrok 4.202MGrok 4.20 lists the larger context window.

Benchmark Deep Dive

AgenticClaude Sonnet 5 wins
BenchmarkClaude Sonnet 5Grok 4.20Result
Terminal-Bench 2.0Source 80.4%47.1%Claude Sonnet 5 leads
BrowseCompSource 84.7%—Not comparable
HLE w/ toolsSource 57.4%—Not comparable
OSWorld-VerifiedSource 81.2%—Not comparable
GDPval-AASource 1607—Not comparable
AA Agentic IndexSource 46.7%—Not comparable
GDPval-AASource 55.4%—Not comparable
AA BriefcaseSource 1388—Not comparable
AA AutomationBenchSource 39.2%—Not comparable
AA EnterpriseOps-GymSource 44.7%—Not comparable
AA Harvey LABSource 90.1%—Not comparable
AA Tau3 BankingSource 28.2%—Not comparable
aaTerminalBench21Source 80.5%—Not comparable
DeepSearchQASource —62.8%Not comparable
Gert LabsSource —38.36%Not comparable
CodingClaude Sonnet 5 wins
BenchmarkClaude Sonnet 5Grok 4.20Result
SWE-bench VerifiedSource 85.2%76.7%Claude Sonnet 5 leads
SWE-bench ProSource 63.2%51.8%Claude Sonnet 5 leads
SWE MultilingualSource 78.3%—Not comparable
SWE MultimodalSource 28.1%—Not comparable
Terminal-Bench 2.0Source 80.4%—Not comparable
FrontierCode 1.1 MainSource 42.7%—Not comparable
cursorBench32Source 61.5%—Not comparable
AA Coding IndexSource 71.5%—Not comparable
AA-SciCodeSource 53.6%—Not comparable
LiveCodeBench ProSource —74.2%Not comparable
Vibe Code BenchSource —4.06%Not comparable
Reasoning
BenchmarkClaude Sonnet 5Grok 4.20Result
AA-LCRSource 70.7%—Not comparable
CritPtSource 16.9%—Not comparable
ARC-AGI-2Source —53.3%Not comparable
Knowledge
BenchmarkClaude Sonnet 5Grok 4.20Result
HLESource 57.4%—Not comparable
HLE w/o toolsSource 43.2%31.6%Claude Sonnet 5 leads
Artificial Analysis Intelligence IndexSource 53.4%—Not comparable
AA-GPQA DiamondSource 91.1%—Not comparable
AA-HLESource 39.6%—Not comparable
AA-Omniscience IndexSource 15.3%—Not comparable
AA-Omniscience AccuracySource 38.3%—Not comparable
AA-Omniscience Hallucination RateSource 37.3%—Not comparable
GPQA-DSource —88.5%Not comparable
HealthBench HardSource —20.3%Not comparable
MedXpertQA (Text)Source —50.2%Not comparable
MultimodalClaude Sonnet 5 wins
BenchmarkClaude Sonnet 5Grok 4.20Result
CharXivSource 88.3%60.9%Claude Sonnet 5 leads
CharXiv w/o toolsSource 77%—Not comparable
AA-MMMU-ProSource 77.3%—Not comparable
Design Arena WebsiteSource 13141257Claude Sonnet 5 leads
MMMU-ProSource —75.2%Not comparable
ERQASource —54.1%Not comparable
SimpleVQASource —57.4%Not comparable
MedXpertQA (MM)Source —65.8%Not comparable
Frequently Asked Questions (4)

Which is better, Claude Sonnet 5 or Grok 4.20?

Claude Sonnet 5 is ahead on BenchLM's BenchAlign leaderboard, 65.32 to 54.68. The biggest single separator in this matchup is Terminal-Bench 2.0, where the scores are 80.4% and 47.1%.

Which is better for coding, Claude Sonnet 5 or Grok 4.20?

Claude Sonnet 5 has the edge for coding in this comparison, averaging 76.7 versus 67.1. Inside this category, SWE-bench Pro is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, Claude Sonnet 5 or Grok 4.20?

Claude Sonnet 5 has the edge for agentic tasks in this comparison, averaging 81.9 versus 47.1. Inside this category, Terminal-Bench 2.0 is the benchmark that creates the most daylight between them.

Which is better for multimodal and grounded tasks, Claude Sonnet 5 or Grok 4.20?

Claude Sonnet 5 has the edge for multimodal and grounded tasks in this comparison, averaging 88.3 versus 70.1. Inside this category, Design Arena Website is the benchmark that creates the most daylight between them.

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