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Model comparison

Claude Mythos 5 vs GPT-5.6 Sol

Data verified

Head-to-head evidence from 6 shared benchmark results across 3 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

83.93/100
Margin
2.0pts
← winning
81.96/100
3 category wins2 category wins

Public leaderboard positions: Claude Mythos 5 #1 (Supported); GPT-5.6 Sol #3 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. Claude Mythos 5 and GPT-5.6 Sol share 6 comparable benchmark results. 5 of 8 categories are comparable. 9 results are unique to Claude Mythos 5; 40 to GPT-5.6 Sol.

Updated July 23, 2026
Shared results
6
Claude Mythos 5 only
9
GPT-5.6 Sol only
40
Comparable categories
5 / 8

Pick Claude Mythos 5 if you want the stronger benchmark profile. GPT-5.6 Sol 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 6 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 has the cleaner BenchAlign overall profile here, landing at 83.93 versus 81.96. It is a real lead, but still close enough that category-level strengths matter more than the headline number.

Claude Mythos 5's sharpest advantage is in coding, where it averages 89.7 against 64.6. The single biggest benchmark swing on the page is SWE-bench Pro, 80.3% to 64.6%. GPT-5.6 Sol 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 / $30.00 output per 1M tokens for GPT-5.6 Sol. Claude Mythos 5 gives you the larger context window at 1M+, compared with 1M for GPT-5.6 Sol.

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 GPT-5.6 Sol
CategoryClaude Mythos 5ΔGPT-5.6 Sol
KnowledgeClaude Mythos 568.5Margin→ 26.1GPT-5.6 Sol94.6
CodingClaude Mythos 589.7Margin← 25.1GPT-5.6 Sol64.6
MultimodalClaude Mythos 593.5Margin← 10.5GPT-5.6 Sol83.0
MathClaude Mythos 597.6Margin← 10.1GPT-5.6 Sol87.5
AgenticClaude Mythos 587.0Margin→ 5.0GPT-5.6 Sol92.0

Decisive benchmark drivers

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

More
A · Claude Mythos 5B · GPT-5.6 Sol

  1. SWE-bench Pro

    Coding
    Source ↗
    A 80.3%B 64.6%
    Winner: Claude Mythos 5Δ 15.7
    SWE-bench Pro: Claude Mythos 5 scored 80.3%; GPT-5.6 Sol scored 64.6%. Claude Mythos 5 wins this benchmark.

  2. BrowseComp

    Agentic
    Source ↗
    A 88%B 92.2%
    Winner: GPT-5.6 SolΔ 4.2
    BrowseComp: Claude Mythos 5 scored 88%; GPT-5.6 Sol scored 92.2%. GPT-5.6 Sol wins this benchmark.

  3. Terminal-Bench 2.0

    Agentic
    Source ↗
    A 88%B 91.9%
    Winner: GPT-5.6 SolΔ 3.9
    Terminal-Bench 2.0: Claude Mythos 5 scored 88%; GPT-5.6 Sol scored 91.9%. GPT-5.6 Sol wins this benchmark.

  4. GPQA

    Knowledge
    Source ↗
    A 94.1%B 94.6%
    Winner: GPT-5.6 SolΔ 0.5
    GPQA: Claude Mythos 5 scored 94.1%; GPT-5.6 Sol scored 94.6%. GPT-5.6 Sol wins this benchmark.

Operational comparison

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

MetricClaude Mythos 5GPT-5.6 SolComparison
Input / output priceUSD per 1M tokensClaude Mythos 5$10 input / $50 outputGPT-5.6 Sol$5 input / $30 outputGPT-5.6 Sol has the lower combined listed price.
Generation speedtokens per secondClaude Mythos 5Not availableGPT-5.6 SolNot availableA complete speed comparison is not available.
First-answer latencyseconds to first tokenClaude Mythos 5Not availableGPT-5.6 SolNot availableA complete latency comparison is not available.
Context windowmaximum listed tokensClaude Mythos 51M+GPT-5.6 Sol1MClaude Mythos 5 lists the larger context window.

Benchmark Deep Dive

AgenticGPT-5.6 Sol wins
BenchmarkClaude Mythos 5GPT-5.6 SolResult
Terminal-Bench 2.0Source 88%91.9%GPT-5.6 Sol leads
OSWorld-VerifiedSource 85%—Not comparable
BrowseCompSource 88%92.2%GPT-5.6 Sol leads
ExploitGymSource 17.5%33.7%GPT-5.6 Sol leads
OSWorld 2.0Source —62.6%Not comparable
CyberGymSource —84.5%Not comparable
ToolathlonSource —58%Not comparable
AA Agentic IndexSource —54.0%Not comparable
τ²-bench resultsSource —85.1%Not comparable
GDPval-AASource —61.8%Not comparable
GDPval-AASource —1736Not comparable
AA BriefcaseSource —1501Not comparable
AA ITBenchSource —56.2%Not comparable
AA Tau3 BankingSource —33.0%Not comparable
AA AutomationBenchSource —51.2%Not comparable
AA Harvey LABSource —87.2%Not comparable
terminalBenchHardSource —65.9%Not comparable
aaTerminalBench21Source —88%Not comparable
CodingClaude Mythos 5 wins
BenchmarkClaude Mythos 5GPT-5.6 SolResult
SWE-bench VerifiedSource 95.5%—Not comparable
SWE-bench ProSource 80.3%64.6%Claude Mythos 5 leads
Terminal-Bench 2.0Source 88.0%91.9%GPT-5.6 Sol leads
deepSweSource —72.7%Not comparable
FrontierCode 1.1 ExtendedSource —60.6%Not comparable
cursorBench32Source —67.2%Not comparable
VulcanBench v3Source —87.0%Not comparable
AA Coding IndexSource —77.4%Not comparable
AA-SciCodeSource —56.1%Not comparable
Reasoning
BenchmarkClaude Mythos 5GPT-5.6 SolResult
ARC-AGI-3Source —7.8%Not comparable
GeneBench-ProSource —28.7%Not comparable
AA-LCRSource —73.7%Not comparable
CritPtSource —32.3%Not comparable
KnowledgeGPT-5.6 Sol wins
BenchmarkClaude Mythos 5GPT-5.6 SolResult
GPQASource 94.1%94.6%GPT-5.6 Sol leads
HLESource 64.5%—Not comparable
HLE w/o toolsSource 59%—Not comparable
GPQA-DSource —94.6%Not comparable
HealthBench ProfessionalSource —60.5%Not comparable
HealthBench HardSource —33.1%Not comparable
Artificial Analysis Intelligence IndexSource —58.9%Not comparable
AA-GPQA DiamondSource —94.1%Not comparable
AA-HLESource —47.2%Not comparable
AA-Omniscience IndexSource —21.7%Not comparable
AA-Omniscience AccuracySource —58.5%Not comparable
AA-Omniscience Hallucination RateSource —88.8%Not comparable
MathClaude Mythos 5 wins
BenchmarkClaude Mythos 5GPT-5.6 SolResult
USAMO 2026Source 97.6%—Not comparable
FrontierMath (legacy)Source —89%Not comparable
FrontierMath v2 (Tiers 1-3)Source —89.000%Not comparable
FrontierMath v2 (Tier 4)Source —83.000%Not comparable
Multilingual
BenchmarkClaude Mythos 5GPT-5.6 SolResult
SWE MultilingualSource 92.2%—Not comparable
MultimodalClaude Mythos 5 wins
BenchmarkClaude Mythos 5GPT-5.6 SolResult
SWE-bench MultimodalSource 54.9%—Not comparable
CharXivSource 93.5%—Not comparable
CharXiv w/o toolsSource 88.9%—Not comparable
MMMU-ProSource —83%Not comparable
MMMU-Pro w/ PythonSource —84.6%Not comparable
AA-MMMU-ProSource —83.4%Not comparable
Inst. Following
BenchmarkClaude Mythos 5GPT-5.6 SolResult
AA-IFBenchSource —72.7%Not comparable
Frequently Asked Questions (6)

Which is better, Claude Mythos 5 or GPT-5.6 Sol?

Claude Mythos 5 is ahead on BenchLM's BenchAlign leaderboard, 83.93 to 81.96. The biggest single separator in this matchup is SWE-bench Pro, where the scores are 80.3% and 64.6%.

Which is better for knowledge tasks, Claude Mythos 5 or GPT-5.6 Sol?

GPT-5.6 Sol has the edge for knowledge tasks in this comparison, averaging 94.6 versus 68.5. Inside this category, GPQA is the benchmark that creates the most daylight between them.

Which is better for coding, Claude Mythos 5 or GPT-5.6 Sol?

Claude Mythos 5 has the edge for coding in this comparison, averaging 89.7 versus 64.6. 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 GPT-5.6 Sol?

Claude Mythos 5 has the edge for math in this comparison, averaging 97.6 versus 87.5. GPT-5.6 Sol stays close enough that the answer can still flip depending on your workload.

Which is better for agentic tasks, Claude Mythos 5 or GPT-5.6 Sol?

GPT-5.6 Sol has the edge for agentic tasks in this comparison, averaging 92 versus 87. Inside this category, ExploitGym is the benchmark that creates the most daylight between them.

Which is better for multimodal and grounded tasks, Claude Mythos 5 or GPT-5.6 Sol?

Claude Mythos 5 has the edge for multimodal and grounded tasks in this comparison, averaging 93.5 versus 83. GPT-5.6 Sol stays close enough that the answer can still flip depending on your workload.

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