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Model comparison

Claude Mythos 5 vs Claude Opus 4.6

Data verified

Head-to-head evidence from 8 shared benchmark results across 3 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

83.01/100
Margin
15.2pts
← winning
67.84/100
4 category wins1 category wins

Public leaderboard positions: Claude Mythos 5 #2 (Supported); Claude Opus 4.6 #19 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. Claude Mythos 5 and Claude Opus 4.6 share 8 comparable benchmark results. 5 of 8 categories are comparable. 7 results are unique to Claude Mythos 5; 38 to Claude Opus 4.6.

Updated July 24, 2026
Shared results
8
Claude Mythos 5 only
7
Claude Opus 4.6 only
38
Comparable categories
5 / 8

Pick Claude Mythos 5 if you want the stronger benchmark profile. Claude Opus 4.6 only becomes the better choice if knowledge is the priority or you want the cheaper token bill.

Confidence note. This is a partial-evidence comparison with 8 shared benchmark results across 3 evidence categories; 5 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, 83.01 to 67.84. 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 mathematics, where it averages 97.6 against 36.3. The single biggest benchmark swing on the page is SWE-bench Pro, 80.3% to 53.4%. Claude Opus 4.6 does hit back in knowledge, so the answer changes if that is the part of the workload you care about most.

Claude Mythos 5 is also the more expensive model on tokens at $10.00 input / $50.00 output per 1M tokens, versus $5.00 input / $25.00 output per 1M tokens for Claude Opus 4.6. That is roughly 2.0x on output cost alone. Claude Mythos 5 is the reasoning model in the pair, while Claude Opus 4.6 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 1M for Claude Opus 4.6.

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 Claude Opus 4.6
CategoryClaude Mythos 5ΔClaude Opus 4.6
MathClaude Mythos 597.6Margin 61.3Claude Opus 4.636.3
CodingClaude Mythos 589.7Margin 21.6Claude Opus 4.668.1
MultimodalClaude Mythos 593.5Margin 16.2Claude Opus 4.677.3
AgenticClaude Mythos 587.0Margin 14.0Claude Opus 4.673.0
KnowledgeClaude Mythos 568.5Margin 0.6Claude Opus 4.669.1

Decisive benchmark drivers

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

More
A · Claude Mythos 5B · Claude Opus 4.6
  1. SWE-bench Pro

    Coding
    Source ↗
    A 80.3%B 53.4%
    Winner: Claude Mythos 5Δ 26.9
    SWE-bench Pro: Claude Mythos 5 scored 80.3%; Claude Opus 4.6 scored 53.4%. Claude Mythos 5 wins this benchmark.
  2. Terminal-Bench 2.0

    Agentic
    Source ↗
    A 88%B 65.4%
    Winner: Claude Mythos 5Δ 22.6
    Terminal-Bench 2.0: Claude Mythos 5 scored 88%; Claude Opus 4.6 scored 65.4%. Claude Mythos 5 wins this benchmark.
  3. SWE-bench Verified

    Coding
    Source ↗
    A 95.5%B 80.8%
    Winner: Claude Mythos 5Δ 14.7
    SWE-bench Verified: Claude Mythos 5 scored 95.5%; Claude Opus 4.6 scored 80.8%. Claude Mythos 5 wins this benchmark.
  4. OSWorld-Verified

    Agentic
    Source ↗
    A 85%B 72.7%
    Winner: Claude Mythos 5Δ 12.3
    OSWorld-Verified: Claude Mythos 5 scored 85%; Claude Opus 4.6 scored 72.7%. Claude Mythos 5 wins this benchmark.
  5. HLE

    Knowledge
    Source ↗
    A 64.5%B 53%
    Winner: Claude Mythos 5Δ 11.5
    HLE: Claude Mythos 5 scored 64.5%; Claude Opus 4.6 scored 53%. 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 5Claude Opus 4.6Comparison
Input / output priceUSD per 1M tokensClaude Mythos 5$10 input / $50 outputClaude Opus 4.6$5 input / $25 outputClaude Opus 4.6 has the lower combined listed price.
Generation speedtokens per secondClaude Mythos 5Not availableClaude Opus 4.640 tok/sA complete speed comparison is not available.
First-answer latencyseconds to first tokenClaude Mythos 5Not availableClaude Opus 4.61.78 sA complete latency comparison is not available.
Context windowmaximum listed tokensClaude Mythos 51M+Claude Opus 4.61MClaude Mythos 5 lists the larger context window.

Benchmark Deep Dive

AgenticClaude Mythos 5 wins
BenchmarkClaude Mythos 5Claude Opus 4.6Result
Terminal-Bench 2.0Source 88%65.4%Claude Mythos 5 leads
OSWorld-VerifiedSource 85%72.7%Claude Mythos 5 leads
BrowseCompSource 88%83.7%Claude Mythos 5 leads
ExploitGymSource 17.5%Not comparable
τ²-bench resultsSource 84.8%Not comparable
Claw-EvalSource 70.4%Not comparable
DeepSearchQASource 73.7%Not comparable
CyberGymSource 66.6%Not comparable
Gert LabsSource 61.85%Not comparable
ResearchClawBenchSource 19.9%Not comparable
JobBenchSource 36.7%Not comparable
CodingClaude Mythos 5 wins
BenchmarkClaude Mythos 5Claude Opus 4.6Result
SWE-bench VerifiedSource 95.5%80.8%Claude Mythos 5 leads
SWE-bench ProSource 80.3%53.4%Claude Mythos 5 leads
Terminal-Bench 2.0Source 88.0%Not comparable
SWE-bench Verified*Source 75.6%Not comparable
LiveCodeBench ProSource 70.7%Not comparable
SWE-RebenchSource 65.3%Not comparable
React Native EvalsSource 84.1%Not comparable
Vibe Code BenchSource 57.57%Not comparable
AA-SciCodeSource 45.7%Not comparable
FrontierCode 1.1 MainSource 26.9%Not comparable
Reasoning
BenchmarkClaude Mythos 5Claude Opus 4.6Result
AA-LCRSource 58.3%Not comparable
CritPtSource 2.8%Not comparable
KnowledgeClaude Opus 4.6 wins
BenchmarkClaude Mythos 5Claude Opus 4.6Result
GPQASource 94.1%91.3%Claude Mythos 5 leads
HLESource 64.5%53%Claude Mythos 5 leads
HLE w/o toolsSource 59%40%Claude Mythos 5 leads
GPQA-DSource 89.2%Not comparable
SuperGPQASource 95%Not comparable
MMLU-ProSource 82%Not comparable
MMLU-Pro (Arcee)Source 89.1%Not comparable
HealthBench HardSource 14.8%Not comparable
MedXpertQA (Text)Source 52.1%Not comparable
Artificial Analysis Intelligence IndexSource 37.8%Not comparable
AA-GPQA DiamondSource 84.0%Not comparable
AA-HLESource 18.6%Not comparable
AA-Omniscience IndexSource 3.5%Not comparable
AA-Omniscience AccuracySource 45.2%Not comparable
AA-Omniscience Hallucination RateSource 76.0%Not comparable
MathClaude Mythos 5 wins
BenchmarkClaude Mythos 5Claude Opus 4.6Result
USAMO 2026Source 97.6%Not comparable
AIME25 (Arcee)Source 99.8%Not comparable
FrontierMath v2 (Tiers 1-3)Source 40.700%Not comparable
FrontierMath v2 (Tier 4)Source 22.900%Not comparable
Multilingual
BenchmarkClaude Mythos 5Claude Opus 4.6Result
SWE MultilingualSource 92.2%Not comparable
MultimodalClaude Mythos 5 wins
BenchmarkClaude Mythos 5Claude Opus 4.6Result
SWE-bench MultimodalSource 54.9%Not comparable
CharXivSource 93.5%Not comparable
CharXiv w/o toolsSource 88.9%Not comparable
MMMU-ProSource 77.3%Not comparable
ERQASource 51.6%Not comparable
ScreenSpot ProSource 83.1%Not comparable
MedXpertQA (MM)Source 64.8%Not comparable
AA-MMMU-ProSource 72.5%Not comparable
Design Arena WebsiteSource 1325Not comparable
Inst. Following
BenchmarkClaude Mythos 5Claude Opus 4.6Result
AA-IFBenchSource 44.6%Not comparable
Frequently Asked Questions (6)

Which is better, Claude Mythos 5 or Claude Opus 4.6?

Claude Mythos 5 is ahead on BenchLM's BenchAlign leaderboard, 83.01 to 67.84. The biggest single separator in this matchup is SWE-bench Pro, where the scores are 80.3% and 53.4%.

Which is better for knowledge tasks, Claude Mythos 5 or Claude Opus 4.6?

Claude Opus 4.6 has the edge for knowledge tasks in this comparison, averaging 69.1 versus 68.5. Inside this category, HLE w/o tools is the benchmark that creates the most daylight between them.

Which is better for coding, Claude Mythos 5 or Claude Opus 4.6?

Claude Mythos 5 has the edge for coding in this comparison, averaging 89.7 versus 68.1. Inside this category, SWE-bench Pro is the benchmark that creates the most daylight between them.

Which is better for math, Claude Mythos 5 or Claude Opus 4.6?

Claude Mythos 5 has the edge for math in this comparison, averaging 97.6 versus 36.3. Claude Opus 4.6 stays close enough that the answer can still flip depending on your workload.

Which is better for agentic tasks, Claude Mythos 5 or Claude Opus 4.6?

Claude Mythos 5 has the edge for agentic tasks in this comparison, averaging 87 versus 73. 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 Mythos 5 or Claude Opus 4.6?

Claude Mythos 5 has the edge for multimodal and grounded tasks in this comparison, averaging 93.5 versus 77.3. Claude Opus 4.6 stays close enough that the answer can still flip depending on your workload.

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Last updated: July 24, 2026