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Model comparison

Claude Mythos 5 vs DeepSeek V3

Data verified

Head-to-head evidence from 2 shared benchmark results across 2 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

83.93/100
Margin
39.0pts
← winning
DeepSeek V3
DeepSeek
44.97/100
2 category wins1 category wins

Public leaderboard positions: Claude Mythos 5 #1 (Supported); DeepSeek V3 #147 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. Claude Mythos 5 and DeepSeek V3 share 2 comparable benchmark results. 3 of 8 categories are comparable. 13 results are unique to Claude Mythos 5; 20 to DeepSeek V3.

Updated July 23, 2026
Shared results
2
Claude Mythos 5 only
13
DeepSeek V3 only
20
Comparable categories
3 / 8

Pick Claude Mythos 5 if you want the stronger benchmark profile. DeepSeek V3 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 2 shared benchmark results across 2 evidence categories; 3 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 44.97. 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 1.7. The single biggest benchmark swing on the page is SWE-bench Verified, 95.5% to 42%. DeepSeek V3 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 $0.27 input / $1.10 output per 1M tokens for DeepSeek V3. That is roughly 45.5x on output cost alone. Claude Mythos 5 is the reasoning model in the pair, while DeepSeek V3 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 DeepSeek V3.

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 DeepSeek V3
CategoryClaude Mythos 5ΔDeepSeek V3
MathClaude Mythos 597.6Margin← 95.9DeepSeek V31.7
CodingClaude Mythos 589.7Margin← 50.8DeepSeek V338.9
KnowledgeClaude Mythos 568.5Margin→ 4.2DeepSeek V372.7
AgenticClaude Mythos 587.0MarginNo overlapDeepSeek V3Not measured
MultimodalClaude Mythos 593.5MarginNo overlapDeepSeek V3Not measured
Inst. FollowingClaude Mythos 5Not measuredMarginNo overlapDeepSeek V386.1

Decisive benchmark drivers

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

More
A · Claude Mythos 5B · DeepSeek V3

  1. SWE-bench Verified

    Coding
    Source ↗
    A 95.5%B 42%
    Winner: Claude Mythos 5Δ 53.5
    SWE-bench Verified: Claude Mythos 5 scored 95.5%; DeepSeek V3 scored 42%. Claude Mythos 5 wins this benchmark.

  2. GPQA

    Knowledge
    Source ↗
    A 94.1%B 59.1%
    Winner: Claude Mythos 5Δ 35
    GPQA: Claude Mythos 5 scored 94.1%; DeepSeek V3 scored 59.1%. 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 5DeepSeek V3Comparison
Input / output priceUSD per 1M tokensClaude Mythos 5$10 input / $50 outputDeepSeek V3$0.27 input / $1.1 outputDeepSeek V3 has the lower combined listed price.
Generation speedtokens per secondClaude Mythos 5Not availableDeepSeek V3Not availableA complete speed comparison is not available.
First-answer latencyseconds to first tokenClaude Mythos 5Not availableDeepSeek V3Not availableA complete latency comparison is not available.
Context windowmaximum listed tokensClaude Mythos 51M+DeepSeek V3128KClaude Mythos 5 lists the larger context window.

Benchmark Deep Dive

Agentic
BenchmarkClaude Mythos 5DeepSeek V3Result
Terminal-Bench 2.0Source 88%—Not comparable
OSWorld-VerifiedSource 85%—Not comparable
BrowseCompSource 88%—Not comparable
ExploitGymSource 17.5%—Not comparable
AA Agentic IndexSource —1.6%Not comparable
τ²-bench resultsSource —22.8%Not comparable
GDPval-AASource —0.0%Not comparable
GDPval-AASource —217Not comparable
CodingClaude Mythos 5 wins
BenchmarkClaude Mythos 5DeepSeek V3Result
SWE-bench VerifiedSource 95.5%42%Claude Mythos 5 leads
SWE-bench ProSource 80.3%—Not comparable
Terminal-Bench 2.0Source 88.0%—Not comparable
LiveCodeBenchSource —37.6%Not comparable
AA Coding IndexSource —23.0%Not comparable
AA-SciCodeSource —35.4%Not comparable
Reasoning
BenchmarkClaude Mythos 5DeepSeek V3Result
AA-LCRSource —29.0%Not comparable
CritPtSource —0.0%Not comparable
KnowledgeDeepSeek V3 wins
BenchmarkClaude Mythos 5DeepSeek V3Result
GPQASource 94.1%59.1%Claude Mythos 5 leads
HLESource 64.5%—Not comparable
HLE w/o toolsSource 59%—Not comparable
MMLU-ProSource —75.9%Not comparable
Artificial Analysis Intelligence IndexSource —14.2%Not comparable
AA-GPQA DiamondSource —55.7%Not comparable
AA-HLESource —3.6%Not comparable
AA-Omniscience IndexSource —-41.3%Not comparable
AA-Omniscience AccuracySource —25.4%Not comparable
AA-Omniscience Hallucination RateSource —89.4%Not comparable
MathClaude Mythos 5 wins
BenchmarkClaude Mythos 5DeepSeek V3Result
USAMO 2026Source 97.6%—Not comparable
FrontierMath v2 (Tiers 1-3)Source —1.724%Not comparable
Multilingual
BenchmarkClaude Mythos 5DeepSeek V3Result
SWE MultilingualSource 92.2%—Not comparable
Multimodal
BenchmarkClaude Mythos 5DeepSeek V3Result
SWE-bench MultimodalSource 54.9%—Not comparable
CharXivSource 93.5%—Not comparable
CharXiv w/o toolsSource 88.9%—Not comparable
Design Arena WebsiteSource —1150Not comparable
Inst. Following
BenchmarkClaude Mythos 5DeepSeek V3Result
IFEvalSource —86.1%Not comparable
AA-IFBenchSource —34.8%Not comparable
Frequently Asked Questions (4)

Which is better, Claude Mythos 5 or DeepSeek V3?

Claude Mythos 5 is ahead on BenchLM's BenchAlign leaderboard, 83.93 to 44.97. The biggest single separator in this matchup is SWE-bench Verified, where the scores are 95.5% and 42%.

Which is better for knowledge tasks, Claude Mythos 5 or DeepSeek V3?

DeepSeek V3 has the edge for knowledge tasks in this comparison, averaging 72.7 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 DeepSeek V3?

Claude Mythos 5 has the edge for coding in this comparison, averaging 89.7 versus 38.9. Inside this category, SWE-bench Verified is the benchmark that creates the most daylight between them.

Which is better for math, Claude Mythos 5 or DeepSeek V3?

Claude Mythos 5 has the edge for math in this comparison, averaging 97.6 versus 1.7. DeepSeek V3 stays close enough that the answer can still flip depending on your workload.

Self-host vs API cost

Estimates at 50,000 req/day · 1000 tokens/req average.

Claude Mythos 5
API / mo$45,000
Self-host / moNot listed
Break-even—
Proprietary model — self-hosting not applicable.
DeepSeek V3
API / mo$1,028
Self-host / mo$18,221
Break-even1.2B/day
Model the full break-even

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