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Model comparison

Claude 4.1 Opus vs Claude Mythos 5

Data verified

Head-to-head evidence from 1 shared benchmark result across 1 category. Overall scores shown here use the public BenchAlign v5 ranking lane.

45.88/100
Margin
38.1pts
winning →
83.93/100
0 category wins1 category wins

Public leaderboard positions: Claude 4.1 Opus #142 (Supported); Claude Mythos 5 #1 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. Claude 4.1 Opus and Claude Mythos 5 share 1 comparable benchmark result. 1 of 8 categories are comparable. 3 results are unique to Claude 4.1 Opus; 14 to Claude Mythos 5.

Updated July 23, 2026
Shared results
1
Claude 4.1 Opus only
3
Claude Mythos 5 only
14
Comparable categories
1 / 8

Pick Claude Mythos 5 if you want the stronger benchmark profile. Claude 4.1 Opus only becomes the better choice if you would rather avoid the extra latency and token burn of a reasoning model.

Confidence note. This is a partial-evidence comparison with 1 shared benchmark result across 1 evidence category; 1 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 45.88. 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 74.5. The single biggest benchmark swing on the page is SWE-bench Verified, 74.5% to 95.5%.

Claude 4.1 Opus is also the more expensive model on tokens at $15.00 input / $75.00 output per 1M tokens, versus $10.00 input / $50.00 output per 1M tokens for Claude Mythos 5. Claude Mythos 5 is the reasoning model in the pair, while Claude 4.1 Opus 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. Claude Mythos 5 gives you the larger context window at 1M+, compared with 200K for Claude 4.1 Opus.

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 4.1 Opus and Claude Mythos 5
CategoryClaude 4.1 OpusΔClaude Mythos 5
CodingClaude 4.1 Opus74.5Margin→ 15.2Claude Mythos 589.7
AgenticClaude 4.1 OpusNot measuredMarginNo overlapClaude Mythos 587.0
KnowledgeClaude 4.1 OpusNot measuredMarginNo overlapClaude Mythos 568.5
MathClaude 4.1 OpusNot measuredMarginNo overlapClaude Mythos 597.6
MultimodalClaude 4.1 OpusNot measuredMarginNo overlapClaude Mythos 593.5

Decisive benchmark drivers

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

More
A · Claude 4.1 OpusB · Claude Mythos 5

  1. SWE-bench Verified

    Coding
    Source ↗
    A 74.5%B 95.5%
    Winner: Claude Mythos 5Δ 21
    SWE-bench Verified: Claude 4.1 Opus scored 74.5%; Claude Mythos 5 scored 95.5%. Claude Mythos 5 wins this benchmark.

Operational comparison

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

MetricClaude 4.1 OpusClaude Mythos 5Comparison
Input / output priceUSD per 1M tokensClaude 4.1 Opus$15 input / $75 outputClaude Mythos 5$10 input / $50 outputClaude Mythos 5 has the lower combined listed price.
Generation speedtokens per secondClaude 4.1 Opus29 tok/sClaude Mythos 5Not availableA complete speed comparison is not available.
First-answer latencyseconds to first tokenClaude 4.1 Opus1.66 sClaude Mythos 5Not availableA complete latency comparison is not available.
Context windowmaximum listed tokensClaude 4.1 Opus200KClaude Mythos 51M+Claude Mythos 5 lists the larger context window.

Benchmark Deep Dive

Agentic
BenchmarkClaude 4.1 OpusClaude Mythos 5Result
JobBenchSource 21.9%—Not comparable
Terminal-Bench 2.0Source —88%Not comparable
OSWorld-VerifiedSource —85%Not comparable
BrowseCompSource —88%Not comparable
ExploitGymSource —17.5%Not comparable
CodingClaude Mythos 5 wins
BenchmarkClaude 4.1 OpusClaude Mythos 5Result
SWE-bench VerifiedSource 74.5%95.5%Claude Mythos 5 leads
SWE-bench ProSource —80.3%Not comparable
Terminal-Bench 2.0Source —88.0%Not comparable
Knowledge
BenchmarkClaude 4.1 OpusClaude Mythos 5Result
Artificial Analysis Intelligence IndexSource 28.2%—Not comparable
GPQASource —94.1%Not comparable
HLESource —64.5%Not comparable
HLE w/o toolsSource —59%Not comparable
Math
BenchmarkClaude 4.1 OpusClaude Mythos 5Result
USAMO 2026Source —97.6%Not comparable
Multilingual
BenchmarkClaude 4.1 OpusClaude Mythos 5Result
SWE MultilingualSource —92.2%Not comparable
Multimodal
BenchmarkClaude 4.1 OpusClaude Mythos 5Result
Design Arena WebsiteSource 1207—Not comparable
SWE-bench MultimodalSource —54.9%Not comparable
CharXivSource —93.5%Not comparable
CharXiv w/o toolsSource —88.9%Not comparable
Frequently Asked Questions (2)

Which is better, Claude 4.1 Opus or Claude Mythos 5?

Claude Mythos 5 is ahead on BenchLM's BenchAlign leaderboard, 83.93 to 45.88. The biggest single separator in this matchup is SWE-bench Verified, where the scores are 74.5% and 95.5%.

Which is better for coding, Claude 4.1 Opus or Claude Mythos 5?

Claude Mythos 5 has the edge for coding in this comparison, averaging 89.7 versus 74.5. Inside this category, SWE-bench Verified is the benchmark that creates the most daylight between them.

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