Skip to main content
BenchLM
Advertise

Model comparison

Claude Opus 4.5 vs Grok 4.20

Data verified

Head-to-head evidence from 7 shared benchmark results across 3 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

64.22/100
Margin
9.5pts
← winning
54.68/100
3 category wins1 category wins

Public leaderboard positions: Claude Opus 4.5 #34 (Supported); Grok 4.20 #88 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. Claude Opus 4.5 and Grok 4.20 share 7 comparable benchmark results. 4 of 8 categories are comparable. 52 results are unique to Claude Opus 4.5; 11 to Grok 4.20.

Updated July 23, 2026
Shared results
7
Claude Opus 4.5 only
52
Grok 4.20 only
11
Comparable categories
4 / 8

Pick Claude Opus 4.5 if you want the stronger benchmark profile. Grok 4.20 only becomes the better choice if multimodal & grounded is the priority or you want the cheaper token bill.

Confidence note. This is a partial-evidence comparison with 7 shared benchmark results across 3 evidence categories; 4 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.

Why this result

Claude Opus 4.5 is clearly ahead on the BenchAlign aggregate, 64.22 to 54.68. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

Claude Opus 4.5's sharpest advantage is in agentic, where it averages 62.6 against 47.1. The single biggest benchmark swing on the page is Terminal-Bench 2.0, 59.3% to 47.1%. Grok 4.20 does hit back in multimodal & grounded, so the answer changes if that is the part of the workload you care about most.

Claude Opus 4.5 is also the more expensive model on tokens at $5.00 input / $25.00 output per 1M tokens, versus $2.00 input / $6.00 output per 1M tokens for Grok 4.20. That is roughly 4.2x on output cost alone. Grok 4.20 is the reasoning model in the pair, while Claude Opus 4.5 is not. That usually helps on harder chain-of-thought-heavy tests, but it can also mean more latency and more token spend in real use. Grok 4.20 gives you the larger context window at 2M, compared with 200K for Claude Opus 4.5.

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 Opus 4.5 and Grok 4.20
CategoryClaude Opus 4.5ΔGrok 4.20
AgenticClaude Opus 4.562.6Margin← 15.5Grok 4.2047.1
ReasoningClaude Opus 4.564.4Margin← 11.1Grok 4.2053.3
CodingClaude Opus 4.571.7Margin← 4.6Grok 4.2067.1
MultimodalClaude Opus 4.569.9Margin→ 0.2Grok 4.2070.1
KnowledgeClaude Opus 4.558.1MarginNo overlapGrok 4.20Not measured
MathClaude Opus 4.557.5MarginNo overlapGrok 4.20Not measured
MultilingualClaude Opus 4.585.7MarginNo overlapGrok 4.20Not measured
Inst. FollowingClaude Opus 4.569.5MarginNo overlapGrok 4.20Not measured

Decisive benchmark drivers

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

More
A · Claude Opus 4.5B · Grok 4.20

  1. Terminal-Bench 2.0

    Agentic
    Source ↗
    A 59.3%B 47.1%
    Winner: Claude Opus 4.5Δ 12.2
    Terminal-Bench 2.0: Claude Opus 4.5 scored 59.3%; Grok 4.20 scored 47.1%. Claude Opus 4.5 wins this benchmark.

  2. CharXiv

    Multimodal
    Source ↗
    A 68.5%B 60.9%
    Winner: Claude Opus 4.5Δ 7.6
    CharXiv: Claude Opus 4.5 scored 68.5%; Grok 4.20 scored 60.9%. Claude Opus 4.5 wins this benchmark.

  3. SWE-bench Pro

    Coding
    Source ↗
    A 57.1%B 51.8%
    Winner: Claude Opus 4.5Δ 5.3
    SWE-bench Pro: Claude Opus 4.5 scored 57.1%; Grok 4.20 scored 51.8%. Claude Opus 4.5 wins this benchmark.

  4. MMMU-Pro

    Multimodal
    Source ↗
    A 70.6%B 75.2%
    Winner: Grok 4.20Δ 4.6
    MMMU-Pro: Claude Opus 4.5 scored 70.6%; Grok 4.20 scored 75.2%. Grok 4.20 wins this benchmark.

  5. SWE-bench Verified

    Coding
    Source ↗
    A 80.9%B 76.7%
    Winner: Claude Opus 4.5Δ 4.2
    SWE-bench Verified: Claude Opus 4.5 scored 80.9%; Grok 4.20 scored 76.7%. Claude Opus 4.5 wins this benchmark.

Operational comparison

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

MetricClaude Opus 4.5Grok 4.20Comparison
Input / output priceUSD per 1M tokensClaude Opus 4.5$5 input / $25 outputGrok 4.20$2 input / $6 outputGrok 4.20 has the lower combined listed price.
Generation speedtokens per secondClaude Opus 4.546 tok/sGrok 4.20233 tok/sGrok 4.20 has the higher measured throughput.
First-answer latencyseconds to first tokenClaude Opus 4.51.01 sGrok 4.2010.33 sClaude Opus 4.5 reaches the first token sooner.
Context windowmaximum listed tokensClaude Opus 4.5200KGrok 4.202MGrok 4.20 lists the larger context window.

Benchmark Deep Dive

AgenticClaude Opus 4.5 wins
BenchmarkClaude Opus 4.5Grok 4.20Result
Terminal-Bench 2.0Source 59.3%47.1%Claude Opus 4.5 leads
OSWorld-VerifiedSource 66.3%—Not comparable
OSWorldSource 66.3%—Not comparable
Claw-EvalSource 59.6%—Not comparable
QwenClawBenchSource 52.3%—Not comparable
τ³-bench resultsSource 70.2%—Not comparable
VITA-BenchSource 23.3%—Not comparable
DeepPlanningSource 26.4%—Not comparable
ToolathlonSource 43.5%—Not comparable
MCP AtlasSource 42.3%—Not comparable
MCP-TasksSource 71.8%—Not comparable
WideResearchSource 76.4%—Not comparable
CyberGymSource 50.6%—Not comparable
τ²-bench resultsSource 86.3%—Not comparable
Gert LabsSource 64.23%38.36%Claude Opus 4.5 leads
JobBenchSource 32.3%—Not comparable
DeepSearchQASource —62.8%Not comparable
CodingClaude Opus 4.5 wins
BenchmarkClaude Opus 4.5Grok 4.20Result
SWE-bench VerifiedSource 80.9%76.7%Claude Opus 4.5 leads
LiveCodeBench v6Source 84.8%—Not comparable
SWE-bench ProSource 57.1%51.8%Claude Opus 4.5 leads
SWE MultilingualSource 77.5%—Not comparable
NL2RepoSource 43.2%—Not comparable
AA-SciCodeSource 47.0%—Not comparable
LiveCodeBench ProSource —74.2%Not comparable
Vibe Code BenchSource —4.06%Not comparable
ReasoningClaude Opus 4.5 wins
BenchmarkClaude Opus 4.5Grok 4.20Result
LongBench v2Source 64.4%—Not comparable
AI-NeedleSource 74%—Not comparable
AA-LCRSource 65.3%—Not comparable
CritPtSource 0.3%—Not comparable
ARC-AGI-2Source —53.3%Not comparable
Knowledge
BenchmarkClaude Opus 4.5Grok 4.20Result
GPQASource 87%—Not comparable
SuperGPQASource 70.6%—Not comparable
MMLU-ProSource 89.5%—Not comparable
MMLU-ReduxSource 96.6%—Not comparable
C-EvalSource 92.2%—Not comparable
HLESource 30.8%—Not comparable
Artificial Analysis Intelligence IndexSource 34.7%—Not comparable
AA-GPQA DiamondSource 81.0%—Not comparable
AA-HLESource 12.9%—Not comparable
AA-Omniscience IndexSource -3.9%—Not comparable
AA-Omniscience AccuracySource 40.7%—Not comparable
AA-Omniscience Hallucination RateSource 75.4%—Not comparable
AA MMLU-ProSource 88.9%—Not comparable
GPQA-DSource —88.5%Not comparable
HLE w/o toolsSource —31.6%Not comparable
HealthBench HardSource —20.3%Not comparable
MedXpertQA (Text)Source —50.2%Not comparable
Math
BenchmarkClaude Opus 4.5Grok 4.20Result
AIME26Source 95.1%—Not comparable
HMMT Feb 2025Source 92.9%—Not comparable
HMMT Nov 2025Source 93.3%—Not comparable
HMMT Feb 2026Source 85.3%—Not comparable
MMAnswerBenchSource 84.0%—Not comparable
FrontierMath v2 (Tiers 1-3)Source 20.690%—Not comparable
FrontierMath v2 (Tier 4)Source 4.167%—Not comparable
Multilingual
BenchmarkClaude Opus 4.5Grok 4.20Result
MMLU-ProXSource 85.7%—Not comparable
NOVA-63Source 56.7%—Not comparable
MultimodalGrok 4.20 wins
BenchmarkClaude Opus 4.5Grok 4.20Result
MMMU-ProSource 70.6%75.2%Grok 4.20 leads
MathVisionSource 74.3%—Not comparable
CharXivSource 68.5%60.9%Claude Opus 4.5 leads
VideoMMMUSource 84.4%—Not comparable
ScreenSpot ProSource 45.7%—Not comparable
V*Source 67.0%—Not comparable
AA-MMMU-ProSource 71.2%—Not comparable
Design Arena WebsiteSource 12771257Claude Opus 4.5 leads
ERQASource —54.1%Not comparable
SimpleVQASource —57.4%Not comparable
MedXpertQA (MM)Source —65.8%Not comparable
Inst. Following
BenchmarkClaude Opus 4.5Grok 4.20Result
IFEvalSource 90.9%—Not comparable
IFBenchSource 58%—Not comparable
AA-IFBenchSource 43.0%—Not comparable
Frequently Asked Questions (5)

Which is better, Claude Opus 4.5 or Grok 4.20?

Claude Opus 4.5 is ahead on BenchLM's BenchAlign leaderboard, 64.22 to 54.68. The biggest single separator in this matchup is Terminal-Bench 2.0, where the scores are 59.3% and 47.1%.

Which is better for coding, Claude Opus 4.5 or Grok 4.20?

Claude Opus 4.5 has the edge for coding in this comparison, averaging 71.7 versus 67.1. Inside this category, SWE-bench Pro is the benchmark that creates the most daylight between them.

Which is better for reasoning, Claude Opus 4.5 or Grok 4.20?

Claude Opus 4.5 has the edge for reasoning in this comparison, averaging 64.4 versus 53.3. Grok 4.20 stays close enough that the answer can still flip depending on your workload.

Which is better for agentic tasks, Claude Opus 4.5 or Grok 4.20?

Claude Opus 4.5 has the edge for agentic tasks in this comparison, averaging 62.6 versus 47.1. Inside this category, Gert Labs is the benchmark that creates the most daylight between them.

Which is better for multimodal and grounded tasks, Claude Opus 4.5 or Grok 4.20?

Grok 4.20 has the edge for multimodal and grounded tasks in this comparison, averaging 70.1 versus 69.9. Inside this category, Design Arena Website is the benchmark that creates the most daylight between them.

Related Comparisons

Explore More

Anthropic Compare Pricing Methodology Find Your Best LLM Overall Rankings
Last updated: July 23, 2026

Choose a model with this week’s evidence

Join 2,000+ readers for ranking moves, pricing changes, and the claims that still need proof.

One email each week. Unsubscribe anytime.