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Model comparison

Claude Mythos 5 vs Gemini 3.1 Pro

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.

83.85/100
Margin
28.8pts
← winning
55.04/100
2 category wins0 category wins

BenchAlign evidence: Claude Mythos 5 supported; Gemini 3.1 Pro estimated. Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. Claude Mythos 5 and Gemini 3.1 Pro share 2 comparable benchmark results. 2 of 8 categories are comparable. 13 results are unique to Claude Mythos 5; 46 to Gemini 3.1 Pro.

Updated July 15, 2026
Shared results
2
Claude Mythos 5 only
13
Gemini 3.1 Pro only
46
Comparable categories
2 / 8

Pick Claude Mythos 5 if you want the stronger benchmark profile. Gemini 3.1 Pro only becomes the better choice if you want the cheaper token bill.

Confidence note. This is a partial-evidence comparison with 2 shared benchmark results across 2 evidence categories; 2 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 finishes one point ahead on BenchLM's provisional leaderboard, 89 to 88. That is enough to call, but not enough to treat as a blowout. This matchup comes down to a few meaningful edges rather than one model dominating the board.

Claude Mythos 5's sharpest advantage is in mathematics, where it averages 99.8 against 31.8. The single biggest benchmark swing on the page is CharXiv, 93.5% to 80.2%.

Claude Mythos 5 is also the more expensive model on tokens at $10.00 input / $50.00 output per 1M tokens, versus $2.00 input / $12.00 output per 1M tokens for Gemini 3.1 Pro. That is roughly 4.2x on output cost alone. Claude Mythos 5 gives you the larger context window at 1M+, compared with 1M for Gemini 3.1 Pro.

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 Gemini 3.1 Pro
CategoryClaude Mythos 5ΔGemini 3.1 Pro
MathClaude Mythos 599.8Margin 68.0Gemini 3.1 Pro31.8
MultimodalClaude Mythos 593.5Margin 10.9Gemini 3.1 Pro82.6
AgenticClaude Mythos 587.0MarginNo overlapGemini 3.1 ProNot measured
CodingClaude Mythos 589.7MarginNo overlapGemini 3.1 ProNot measured
ReasoningClaude Mythos 5Not measuredMarginNo overlapGemini 3.1 Pro77.1
KnowledgeClaude Mythos 568.5MarginNo overlapGemini 3.1 ProNot measured

Decisive benchmark drivers

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

More
A · Claude Mythos 5B · Gemini 3.1 Pro
  1. CharXiv

    Multimodal
    Source ↗
    A 93.5%B 80.2%
    Winner: Claude Mythos 5Δ 13.3
    CharXiv: Claude Mythos 5 scored 93.5%; Gemini 3.1 Pro scored 80.2%. 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 5Gemini 3.1 ProComparison
Input / output priceUSD per 1M tokensClaude Mythos 5$10 input / $50 outputGemini 3.1 Pro$2 input / $12 outputGemini 3.1 Pro has the lower combined listed price.
Generation speedtokens per secondClaude Mythos 5Not availableGemini 3.1 Pro109 tok/sA complete speed comparison is not available.
First-answer latencyseconds to first tokenClaude Mythos 5Not availableGemini 3.1 Pro29.71 sA complete latency comparison is not available.
Context windowmaximum listed tokensClaude Mythos 51M+Gemini 3.1 Pro1MListed context windows are equal.

Benchmark Deep Dive

Agentic
BenchmarkClaude Mythos 5Gemini 3.1 ProResult
Terminal-Bench 2.0Source 88%Not comparable
OSWorld-VerifiedSource 85%Not comparable
BrowseCompSource 88%Not comparable
ExploitGymSource 17.5%Not comparable
Claw-EvalSource 57.8%Not comparable
DeepSearchQASource 69.7%Not comparable
τ²-bench resultsSource 95.6%Not comparable
AA Agentic IndexSource 21.4%Not comparable
APEX-Agents-AASource 32.0%Not comparable
GDPval-AASource 23.1%Not comparable
GDPval-AASource 962Not comparable
Gert LabsSource 49.91%Not comparable
ResearchClawBenchSource 13.3%Not comparable
AA AutomationBenchSource 37.5%Not comparable
AA EnterpriseOps-GymSource 42.2%Not comparable
AA Harvey LABSource 0.0%Not comparable
AA ITBenchSource 30.3%Not comparable
AA Tau3 BankingSource 16.5%Not comparable
Coding
BenchmarkClaude Mythos 5Gemini 3.1 ProResult
SWE-bench VerifiedSource 95.5%Not comparable
SWE-bench ProSource 80.3%Not comparable
Terminal-Bench 2.0Source 88.0%Not comparable
LiveCodeBench ProSource 82.9%Not comparable
React Native EvalsSource 78.9%Not comparable
Vibe Code BenchSource 32.03%Not comparable
AA Coding IndexSource 68.8%Not comparable
Terminal-Bench HardSource 53.8%Not comparable
AA-SciCodeSource 58.9%Not comparable
AA Terminal-Bench 2.1Source 73.8%Not comparable
Reasoning
BenchmarkClaude Mythos 5Gemini 3.1 ProResult
ARC-AGI-2Source 77.1%Not comparable
AA-LCRSource 72.7%Not comparable
CritPtSource 17.7%Not comparable
Knowledge
BenchmarkClaude Mythos 5Gemini 3.1 ProResult
GPQASource 94.1%Not comparable
HLESource 64.5%Not comparable
HLE w/o toolsSource 59%45.4%Claude Mythos 5 leads
GPQA-DSource 94.3%Not comparable
HealthBench HardSource 20.6%Not comparable
MedXpertQA (Text)Source 71.5%Not comparable
Artificial Analysis Intelligence IndexSource 46.5%Not comparable
AA-GPQA DiamondSource 94.1%Not comparable
AA-HLESource 44.7%Not comparable
AA-Omniscience IndexSource 32.9%Not comparable
AA-Omniscience AccuracySource 55.3%Not comparable
AA-Omniscience Hallucination RateSource 49.9%Not comparable
MathClaude Mythos 5 wins
BenchmarkClaude Mythos 5Gemini 3.1 ProResult
USAMO 2026Source 99.8%Not comparable
FrontierMath v2 (Tiers 1-3)Source 36.900%Not comparable
FrontierMath v2 (Tier 4)Source 16.700%Not comparable
Multilingual
BenchmarkClaude Mythos 5Gemini 3.1 ProResult
SWE MultilingualSource 92.2%Not comparable
AA Global-MMLU-LiteSource 93.2%Not comparable
MultimodalClaude Mythos 5 wins
BenchmarkClaude Mythos 5Gemini 3.1 ProResult
SWE-bench MultimodalSource 54.9%Not comparable
CharXivSource 93.5%80.2%Claude Mythos 5 leads
CharXiv w/o toolsSource 88.9%Not comparable
MMMU-ProSource 83.9%Not comparable
ERQASource 69.4%Not comparable
SimpleVQASource 72.4%Not comparable
ScreenSpot ProSource 84.4%Not comparable
ZeroBenchSource 29.0%Not comparable
MedXpertQA (MM)Source 81.3%Not comparable
GDPval-AASource 1320Not comparable
AA-MMMU-ProSource 82.4%Not comparable
Design Arena WebsiteSource 1285Not comparable
Inst. Following
BenchmarkClaude Mythos 5Gemini 3.1 ProResult
AA-IFBenchSource 77.1%Not comparable
Frequently Asked Questions (3)

Which is better, Claude Mythos 5 or Gemini 3.1 Pro?

Claude Mythos 5 is ahead on BenchLM's provisional leaderboard, 89 to 88. The biggest single separator in this matchup is CharXiv, where the scores are 93.5% and 80.2%.

Which is better for math, Claude Mythos 5 or Gemini 3.1 Pro?

Claude Mythos 5 has the edge for math in this comparison, averaging 99.8 versus 31.8. Gemini 3.1 Pro stays close enough that the answer can still flip depending on your workload.

Which is better for multimodal and grounded tasks, Claude Mythos 5 or Gemini 3.1 Pro?

Claude Mythos 5 has the edge for multimodal and grounded tasks in this comparison, averaging 93.5 versus 82.6. Inside this category, CharXiv is the benchmark that creates the most daylight between them.

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Last updated: July 15, 2026

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