Skip to main content
BenchLM
Advertise

Model comparison

Claude Mythos 5 vs Qwen3.5 397B

Data verified

Head-to-head evidence from 7 shared benchmark results across 4 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

83.93/100
Margin
26.9pts
← winning
57.01/100
5 category wins0 category wins

Public leaderboard positions: Claude Mythos 5 #1 (Supported); Qwen3.5 397B #71 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. Claude Mythos 5 and Qwen3.5 397B share 7 comparable benchmark results. 5 of 8 categories are comparable. 8 results are unique to Claude Mythos 5; 48 to Qwen3.5 397B.

Updated July 23, 2026
Shared results
7
Claude Mythos 5 only
8
Qwen3.5 397B only
48
Comparable categories
5 / 8

Pick Claude Mythos 5 if you want the stronger benchmark profile. Qwen3.5 397B only becomes the better choice if you want the cheaper token bill or you would rather avoid the extra latency and token burn of a reasoning model.

Confidence note. This is a partial-evidence comparison with 7 shared benchmark results across 4 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, 83.93 to 57.01. 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 agentic, where it averages 87 against 56.5. The single biggest benchmark swing on the page is HLE, 64.5% to 28.7%.

Claude Mythos 5 is also the more expensive model on tokens at $10.00 input / $50.00 output per 1M tokens, versus $0.60 input / $3.60 output per 1M tokens for Qwen3.5 397B. That is roughly 13.9x on output cost alone. Claude Mythos 5 is the reasoning model in the pair, while Qwen3.5 397B 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 128K for Qwen3.5 397B.

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 Qwen3.5 397B
CategoryClaude Mythos 5ΔQwen3.5 397B
AgenticClaude Mythos 587.0Margin← 30.5Qwen3.5 397B56.5
CodingClaude Mythos 589.7Margin← 23.2Qwen3.5 397B66.5
MultimodalClaude Mythos 593.5Margin← 13.9Qwen3.5 397B79.6
KnowledgeClaude Mythos 568.5Margin← 11.9Qwen3.5 397B56.6
MathClaude Mythos 597.6Margin← 7.0Qwen3.5 397B90.6
ReasoningClaude Mythos 5Not measuredMarginNo overlapQwen3.5 397B63.2
MultilingualClaude Mythos 5Not measuredMarginNo overlapQwen3.5 397B84.7
Inst. FollowingClaude Mythos 5Not measuredMarginNo overlapQwen3.5 397B92.6

Decisive benchmark drivers

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

More
A · Claude Mythos 5B · Qwen3.5 397B

  1. HLE

    Knowledge
    Source ↗
    A 64.5%B 28.7%
    Winner: Claude Mythos 5Δ 35.8
    HLE: Claude Mythos 5 scored 64.5%; Qwen3.5 397B scored 28.7%. Claude Mythos 5 wins this benchmark.

  2. Terminal-Bench 2.0

    Agentic
    Source ↗
    A 88%B 52.5%
    Winner: Claude Mythos 5Δ 35.5
    Terminal-Bench 2.0: Claude Mythos 5 scored 88%; Qwen3.5 397B scored 52.5%. Claude Mythos 5 wins this benchmark.

  3. SWE-bench Pro

    Coding
    Source ↗
    A 80.3%B 50.9%
    Winner: Claude Mythos 5Δ 29.4
    SWE-bench Pro: Claude Mythos 5 scored 80.3%; Qwen3.5 397B scored 50.9%. Claude Mythos 5 wins this benchmark.

  4. BrowseComp

    Agentic
    Source ↗
    A 88%B 62%
    Winner: Claude Mythos 5Δ 26
    BrowseComp: Claude Mythos 5 scored 88%; Qwen3.5 397B scored 62%. Claude Mythos 5 wins this benchmark.

  5. SWE-bench Verified

    Coding
    Source ↗
    A 95.5%B 76.2%
    Winner: Claude Mythos 5Δ 19.3
    SWE-bench Verified: Claude Mythos 5 scored 95.5%; Qwen3.5 397B scored 76.2%. 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 5Qwen3.5 397BComparison
Input / output priceUSD per 1M tokensClaude Mythos 5$10 input / $50 outputQwen3.5 397B$0.6 input / $3.6 outputQwen3.5 397B has the lower combined listed price.
Generation speedtokens per secondClaude Mythos 5Not availableQwen3.5 397B96 tok/sA complete speed comparison is not available.
First-answer latencyseconds to first tokenClaude Mythos 5Not availableQwen3.5 397B2.44 sA complete latency comparison is not available.
Context windowmaximum listed tokensClaude Mythos 51M+Qwen3.5 397B128KClaude Mythos 5 lists the larger context window.

Benchmark Deep Dive

AgenticClaude Mythos 5 wins
BenchmarkClaude Mythos 5Qwen3.5 397BResult
Terminal-Bench 2.0Source 88%52.5%Claude Mythos 5 leads
OSWorld-VerifiedSource 85%—Not comparable
BrowseCompSource 88%62%Claude Mythos 5 leads
ExploitGymSource 17.5%—Not comparable
Claw-EvalSource —56.8%Not comparable
QwenClawBenchSource —51.8%Not comparable
τ³-bench resultsSource —68.4%Not comparable
VITA-BenchSource —43.7%Not comparable
DeepPlanningSource —37.6%Not comparable
ToolathlonSource —36.3%Not comparable
MCP AtlasSource —46.1%Not comparable
MCP-TasksSource —74.2%Not comparable
WideResearchSource —74.0%Not comparable
τ²-bench resultsSource —95.6%Not comparable
Gert LabsSource —46.76%Not comparable
ResearchClawBenchSource —14.2%Not comparable
AA Agentic IndexSource —19.9%Not comparable
APEX-Agents-AASource —15.3%Not comparable
GDPval-AASource —23.1%Not comparable
GDPval-AASource —962Not comparable
CodingClaude Mythos 5 wins
BenchmarkClaude Mythos 5Qwen3.5 397BResult
SWE-bench VerifiedSource 95.5%76.2%Claude Mythos 5 leads
SWE-bench ProSource 80.3%50.9%Claude Mythos 5 leads
Terminal-Bench 2.0Source 88.0%—Not comparable
LiveCodeBench v6Source —83.6%Not comparable
AA-SciCodeSource —42.0%Not comparable
AA Coding IndexSource —48.2%Not comparable
Reasoning
BenchmarkClaude Mythos 5Qwen3.5 397BResult
LongBench v2Source —63.2%Not comparable
AI-NeedleSource —68.7%Not comparable
AA-LCRSource —65.7%Not comparable
CritPtSource —1.7%Not comparable
KnowledgeClaude Mythos 5 wins
BenchmarkClaude Mythos 5Qwen3.5 397BResult
GPQASource 94.1%88.4%Claude Mythos 5 leads
HLESource 64.5%28.7%Claude Mythos 5 leads
HLE w/o toolsSource 59%—Not comparable
SuperGPQASource —70.4%Not comparable
MMLU-ProSource —87.8%Not comparable
MMLU-ReduxSource —94.9%Not comparable
C-EvalSource —93%Not comparable
Artificial Analysis Intelligence IndexSource —33.7%Not comparable
AA-GPQA DiamondSource —89.3%Not comparable
AA-HLESource —27.3%Not comparable
AA-Omniscience IndexSource —-29.8%Not comparable
AA-Omniscience AccuracySource —31.4%Not comparable
AA-Omniscience Hallucination RateSource —89.1%Not comparable
MathClaude Mythos 5 wins
BenchmarkClaude Mythos 5Qwen3.5 397BResult
USAMO 2026Source 97.6%—Not comparable
AIME26Source —93.3%Not comparable
HMMT Feb 2025Source —94.8%Not comparable
HMMT Nov 2025Source —92.7%Not comparable
HMMT Feb 2026Source —87.9%Not comparable
MMAnswerBenchSource —80.9%Not comparable
Multilingual
BenchmarkClaude Mythos 5Qwen3.5 397BResult
SWE MultilingualSource 92.2%—Not comparable
MMLU-ProXSource —84.7%Not comparable
NOVA-63Source —59.1%Not comparable
MultimodalClaude Mythos 5 wins
BenchmarkClaude Mythos 5Qwen3.5 397BResult
SWE-bench MultimodalSource 54.9%—Not comparable
CharXivSource 93.5%80.8%Claude Mythos 5 leads
CharXiv w/o toolsSource 88.9%—Not comparable
MMMU-ProSource —79%Not comparable
MathVisionSource —88.6%Not comparable
VideoMMMUSource —84.7%Not comparable
ScreenSpot ProSource —65.6%Not comparable
V*Source —95.8%Not comparable
AA-MMMU-ProSource —77.3%Not comparable
Inst. Following
BenchmarkClaude Mythos 5Qwen3.5 397BResult
IFEvalSource —92.6%Not comparable
AA-IFBenchSource —78.8%Not comparable
Frequently Asked Questions (6)

Which is better, Claude Mythos 5 or Qwen3.5 397B?

Claude Mythos 5 is ahead on BenchLM's BenchAlign leaderboard, 83.93 to 57.01. The biggest single separator in this matchup is HLE, where the scores are 64.5% and 28.7%.

Which is better for knowledge tasks, Claude Mythos 5 or Qwen3.5 397B?

Claude Mythos 5 has the edge for knowledge tasks in this comparison, averaging 68.5 versus 56.6. Inside this category, HLE is the benchmark that creates the most daylight between them.

Which is better for coding, Claude Mythos 5 or Qwen3.5 397B?

Claude Mythos 5 has the edge for coding in this comparison, averaging 89.7 versus 66.5. 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 Qwen3.5 397B?

Claude Mythos 5 has the edge for math in this comparison, averaging 97.6 versus 90.6. Qwen3.5 397B stays close enough that the answer can still flip depending on your workload.

Which is better for agentic tasks, Claude Mythos 5 or Qwen3.5 397B?

Claude Mythos 5 has the edge for agentic tasks in this comparison, averaging 87 versus 56.5. 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 Qwen3.5 397B?

Claude Mythos 5 has the edge for multimodal and grounded tasks in this comparison, averaging 93.5 versus 79.6. Inside this category, CharXiv 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.