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Model comparison

Claude Mythos 5 vs Grok 4.5

Data verified

Head-to-head evidence from 3 shared benchmark results across 2 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

83.93/100
Margin
7.2pts
← winning
76.72/100
2 category wins0 category wins

Public leaderboard positions: Claude Mythos 5 #1 (Supported); Grok 4.5 #7 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. Claude Mythos 5 and Grok 4.5 share 3 comparable benchmark results. 2 of 8 categories are comparable. 12 results are unique to Claude Mythos 5; 25 to Grok 4.5.

Updated July 23, 2026
Shared results
3
Claude Mythos 5 only
12
Grok 4.5 only
25
Comparable categories
2 / 8

Pick Claude Mythos 5 if you want the stronger benchmark profile. Grok 4.5 only becomes the better choice if you want the cheaper token bill.

Confidence note. This is a partial-evidence comparison with 3 shared benchmark results across 2 evidence categories; 2 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.

Why this result

Claude Mythos 5 is clearly ahead on the BenchAlign aggregate, 83.93 to 76.72. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

Claude Mythos 5's sharpest advantage is in coding, where it averages 89.7 against 64.7. The single biggest benchmark swing on the page is SWE-bench Pro, 80.3% to 64.7%.

Claude Mythos 5 is also the more expensive model on tokens at $10.00 input / $50.00 output per 1M tokens, versus $2.00 input / $6.00 output per 1M tokens for Grok 4.5. That is roughly 8.3x on output cost alone. Claude Mythos 5 gives you the larger context window at 1M+, compared with 500K for Grok 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 Mythos 5 and Grok 4.5
CategoryClaude Mythos 5ΔGrok 4.5
CodingClaude Mythos 589.7Margin← 25.0Grok 4.564.7
AgenticClaude Mythos 587.0Margin← 3.7Grok 4.583.3
KnowledgeClaude Mythos 568.5MarginNo overlapGrok 4.5Not measured
MathClaude Mythos 597.6MarginNo overlapGrok 4.5Not measured
MultimodalClaude Mythos 593.5MarginNo overlapGrok 4.5Not measured

Decisive benchmark drivers

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

More
A · Claude Mythos 5B · Grok 4.5

  1. SWE-bench Pro

    Coding
    Source ↗
    A 80.3%B 64.7%
    Winner: Claude Mythos 5Δ 15.6
    SWE-bench Pro: Claude Mythos 5 scored 80.3%; Grok 4.5 scored 64.7%. Claude Mythos 5 wins this benchmark.

  2. Terminal-Bench 2.0

    Agentic
    Source ↗
    A 88%B 83.3%
    Winner: Claude Mythos 5Δ 4.7
    Terminal-Bench 2.0: Claude Mythos 5 scored 88%; Grok 4.5 scored 83.3%. Claude Mythos 5 wins this benchmark.

Operational comparison

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

MetricClaude Mythos 5Grok 4.5Comparison
Input / output priceUSD per 1M tokensClaude Mythos 5$10 input / $50 outputGrok 4.5$2 input / $6 outputGrok 4.5 has the lower combined listed price.
Generation speedtokens per secondClaude Mythos 5Not availableGrok 4.5Not availableA complete speed comparison is not available.
First-answer latencyseconds to first tokenClaude Mythos 5Not availableGrok 4.5Not availableA complete latency comparison is not available.
Context windowmaximum listed tokensClaude Mythos 51M+Grok 4.5500KClaude Mythos 5 lists the larger context window.

Benchmark Deep Dive

AgenticClaude Mythos 5 wins
BenchmarkClaude Mythos 5Grok 4.5Result
Terminal-Bench 2.0Source 88%83.3%Claude Mythos 5 leads
OSWorld-VerifiedSource 85%—Not comparable
BrowseCompSource 88%—Not comparable
ExploitGymSource 17.5%—Not comparable
deepSweSource —53%Not comparable
AA Agentic IndexSource —45.7%Not comparable
GDPval-AASource —51.7%Not comparable
GDPval-AASource —1535Not comparable
AA BriefcaseSource —1323Not comparable
AA AutomationBenchSource —51.4%Not comparable
AA EnterpriseOps-GymSource —40.8%Not comparable
AA Harvey LABSource —92.4%Not comparable
AA Tau3 BankingSource —32.6%Not comparable
aaTerminalBench21Source —81.6%Not comparable
CodingClaude Mythos 5 wins
BenchmarkClaude Mythos 5Grok 4.5Result
SWE-bench VerifiedSource 95.5%—Not comparable
SWE-bench ProSource 80.3%64.7%Claude Mythos 5 leads
Terminal-Bench 2.0Source 88.0%83.3%Claude Mythos 5 leads
SWE MultilingualSource —78%Not comparable
cursorBench32Source —66.7%Not comparable
VulcanBench v3Source —91.3%Not comparable
AA Coding IndexSource —72.5%Not comparable
AA-SciCodeSource —54.1%Not comparable
Reasoning
BenchmarkClaude Mythos 5Grok 4.5Result
AA-LCRSource —67.7%Not comparable
CritPtSource —15.4%Not comparable
Knowledge
BenchmarkClaude Mythos 5Grok 4.5Result
GPQASource 94.1%—Not comparable
HLESource 64.5%—Not comparable
HLE w/o toolsSource 59%—Not comparable
Artificial Analysis Intelligence IndexSource —53.8%Not comparable
AA-GPQA DiamondSource —93.1%Not comparable
AA-HLESource —40.3%Not comparable
AA-Omniscience IndexSource —26.4%Not comparable
AA-Omniscience AccuracySource —52.1%Not comparable
AA-Omniscience Hallucination RateSource —53.5%Not comparable
Math
BenchmarkClaude Mythos 5Grok 4.5Result
USAMO 2026Source 97.6%—Not comparable
Multilingual
BenchmarkClaude Mythos 5Grok 4.5Result
SWE MultilingualSource 92.2%—Not comparable
Multimodal
BenchmarkClaude Mythos 5Grok 4.5Result
SWE-bench MultimodalSource 54.9%—Not comparable
CharXivSource 93.5%—Not comparable
CharXiv w/o toolsSource 88.9%—Not comparable
AA-MMMU-ProSource —80.4%Not comparable
Design Arena WebsiteSource —1325Not comparable
Frequently Asked Questions (3)

Which is better, Claude Mythos 5 or Grok 4.5?

Claude Mythos 5 is ahead on BenchLM's BenchAlign leaderboard, 83.93 to 76.72. The biggest single separator in this matchup is SWE-bench Pro, where the scores are 80.3% and 64.7%.

Which is better for coding, Claude Mythos 5 or Grok 4.5?

Claude Mythos 5 has the edge for coding in this comparison, averaging 89.7 versus 64.7. Inside this category, SWE-bench Pro is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, Claude Mythos 5 or Grok 4.5?

Claude Mythos 5 has the edge for agentic tasks in this comparison, averaging 87 versus 83.3. Inside this category, Terminal-Bench 2.0 is the benchmark that creates the most daylight between them.

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