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Model comparison

Claude 4 Sonnet 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.

42.79/100
Margin
41.1pts
winning →
83.93/100
0 category wins1 category wins

Public leaderboard positions: Claude 4 Sonnet #158 (Supported); Claude Mythos 5 #1 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. Claude 4 Sonnet and Claude Mythos 5 share 1 comparable benchmark result. 1 of 8 categories are comparable. 15 results are unique to Claude 4 Sonnet; 14 to Claude Mythos 5.

Updated July 23, 2026
Shared results
1
Claude 4 Sonnet only
15
Claude Mythos 5 only
14
Comparable categories
1 / 8

Pick Claude Mythos 5 if you want the stronger benchmark profile. Claude 4 Sonnet 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 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 42.79. 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 72.7. The single biggest benchmark swing on the page is SWE-bench Verified, 72.7% to 95.5%.

Claude Mythos 5 is also the more expensive model on tokens at $10.00 input / $50.00 output per 1M tokens, versus $3.00 input / $15.00 output per 1M tokens for Claude 4 Sonnet. That is roughly 3.3x on output cost alone. Claude Mythos 5 is the reasoning model in the pair, while Claude 4 Sonnet 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 Sonnet.

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 Sonnet and Claude Mythos 5
CategoryClaude 4 SonnetΔClaude Mythos 5
CodingClaude 4 Sonnet72.7Margin→ 17.0Claude Mythos 589.7
AgenticClaude 4 SonnetNot measuredMarginNo overlapClaude Mythos 587.0
KnowledgeClaude 4 SonnetNot measuredMarginNo overlapClaude Mythos 568.5
MathClaude 4 SonnetNot measuredMarginNo overlapClaude Mythos 597.6
MultimodalClaude 4 SonnetNot measuredMarginNo overlapClaude Mythos 593.5

Decisive benchmark drivers

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

More
A · Claude 4 SonnetB · Claude Mythos 5

  1. SWE-bench Verified

    Coding
    Source ↗
    A 72.7%B 95.5%
    Winner: Claude Mythos 5Δ 22.8
    SWE-bench Verified: Claude 4 Sonnet scored 72.7%; 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 SonnetClaude Mythos 5Comparison
Input / output priceUSD per 1M tokensClaude 4 Sonnet$3 input / $15 outputClaude Mythos 5$10 input / $50 outputClaude 4 Sonnet has the lower combined listed price.
Generation speedtokens per secondClaude 4 Sonnet40 tok/sClaude Mythos 5Not availableA complete speed comparison is not available.
First-answer latencyseconds to first tokenClaude 4 Sonnet1.33 sClaude Mythos 5Not availableA complete latency comparison is not available.
Context windowmaximum listed tokensClaude 4 Sonnet200KClaude Mythos 51M+Claude Mythos 5 lists the larger context window.

Benchmark Deep Dive

Agentic
BenchmarkClaude 4 SonnetClaude Mythos 5Result
τ²-bench resultsSource 52.3%—Not comparable
Gert LabsSource 39.66%—Not comparable
JobBenchSource 18.4%—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 SonnetClaude Mythos 5Result
SWE-bench VerifiedSource 72.7%95.5%Claude Mythos 5 leads
AA-SciCodeSource 37.3%—Not comparable
SWE-bench ProSource —80.3%Not comparable
Terminal-Bench 2.0Source —88.0%Not comparable
Reasoning
BenchmarkClaude 4 SonnetClaude Mythos 5Result
AA-LCRSource 44.3%—Not comparable
CritPtSource 1.1%—Not comparable
Knowledge
BenchmarkClaude 4 SonnetClaude Mythos 5Result
Artificial Analysis Intelligence IndexSource 25.5%—Not comparable
AA-GPQA DiamondSource 68.3%—Not comparable
AA-HLESource 4.0%—Not comparable
AA-Omniscience IndexSource -9.2%—Not comparable
AA-Omniscience AccuracySource 22.4%—Not comparable
AA-Omniscience Hallucination RateSource 40.8%—Not comparable
GPQASource —94.1%Not comparable
HLESource —64.5%Not comparable
HLE w/o toolsSource —59%Not comparable
Math
BenchmarkClaude 4 SonnetClaude Mythos 5Result
USAMO 2026Source —97.6%Not comparable
Multilingual
BenchmarkClaude 4 SonnetClaude Mythos 5Result
SWE MultilingualSource —92.2%Not comparable
Multimodal
BenchmarkClaude 4 SonnetClaude Mythos 5Result
AA-MMMU-ProSource 62.4%—Not comparable
Design Arena WebsiteSource 1175—Not comparable
SWE-bench MultimodalSource —54.9%Not comparable
CharXivSource —93.5%Not comparable
CharXiv w/o toolsSource —88.9%Not comparable
Inst. Following
BenchmarkClaude 4 SonnetClaude Mythos 5Result
AA-IFBenchSource 45.4%—Not comparable
Frequently Asked Questions (2)

Which is better, Claude 4 Sonnet or Claude Mythos 5?

Claude Mythos 5 is ahead on BenchLM's BenchAlign leaderboard, 83.93 to 42.79. The biggest single separator in this matchup is SWE-bench Verified, where the scores are 72.7% and 95.5%.

Which is better for coding, Claude 4 Sonnet or Claude Mythos 5?

Claude Mythos 5 has the edge for coding in this comparison, averaging 89.7 versus 72.7. Inside this category, SWE-bench Verified is the benchmark that creates the most daylight between them.

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