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Model comparison

Claude Mythos 5 vs Gemma 4 12B

Data verified

Head-to-head evidence from 2 shared benchmark results across 1 category. Overall scores shown here use the public BenchAlign v5 ranking lane.

83.93/100
Margin
36.6pts
← winning
47.29/100
2 category wins1 category wins

Public leaderboard positions: Claude Mythos 5 #1 (Supported); Gemma 4 12B #137 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. Claude Mythos 5 and Gemma 4 12B share 2 comparable benchmark results. 3 of 8 categories are comparable. 13 results are unique to Claude Mythos 5; 21 to Gemma 4 12B.

Updated July 23, 2026
Shared results
2
Claude Mythos 5 only
13
Gemma 4 12B only
21
Comparable categories
3 / 8

Pick Claude Mythos 5 if you want the stronger benchmark profile. Gemma 4 12B only becomes the better choice if knowledge is the priority.

Confidence note. This is a partial-evidence comparison with 2 shared benchmark results across 1 evidence category; 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 47.29. 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 multimodal & grounded, where it averages 93.5 against 69.1. The single biggest benchmark swing on the page is GPQA, 94.1% to 78.8%. Gemma 4 12B does hit back in knowledge, so the answer changes if that is the part of the workload you care about most.

Claude Mythos 5 gives you the larger context window at 1M+, compared with 256K for Gemma 4 12B.

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 Gemma 4 12B
CategoryClaude Mythos 5ΔGemma 4 12B
MultimodalClaude Mythos 593.5Margin 24.4Gemma 4 12B69.1
MathClaude Mythos 597.6Margin 20.1Gemma 4 12B77.5
KnowledgeClaude Mythos 568.5Margin 9.0Gemma 4 12B77.5
AgenticClaude Mythos 587.0MarginNo overlapGemma 4 12BNot measured
CodingClaude Mythos 589.7MarginNo overlapGemma 4 12BNot measured
ReasoningClaude Mythos 5Not measuredMarginNo overlapGemma 4 12B43.4

Decisive benchmark drivers

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

More
A · Claude Mythos 5B · Gemma 4 12B
  1. GPQA

    Knowledge
    Source ↗
    A 94.1%B 78.8%
    Winner: Claude Mythos 5Δ 15.3
    GPQA: Claude Mythos 5 scored 94.1%; Gemma 4 12B scored 78.8%. 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 5Gemma 4 12BComparison
Input / output priceUSD per 1M tokensClaude Mythos 5$10 input / $50 outputGemma 4 12BNot availableA complete price comparison is not available.
Generation speedtokens per secondClaude Mythos 5Not availableGemma 4 12BNot availableA complete speed comparison is not available.
First-answer latencyseconds to first tokenClaude Mythos 5Not availableGemma 4 12BNot availableA complete latency comparison is not available.
Context windowmaximum listed tokensClaude Mythos 51M+Gemma 4 12B256KClaude Mythos 5 lists the larger context window.

Benchmark Deep Dive

Agentic
BenchmarkClaude Mythos 5Gemma 4 12BResult
Terminal-Bench 2.0Source 88%Not comparable
OSWorld-VerifiedSource 85%Not comparable
BrowseCompSource 88%Not comparable
ExploitGymSource 17.5%Not comparable
τ²-bench resultsSource 36.3%Not comparable
Coding
BenchmarkClaude Mythos 5Gemma 4 12BResult
SWE-bench VerifiedSource 95.5%Not comparable
SWE-bench ProSource 80.3%Not comparable
Terminal-Bench 2.0Source 88.0%Not comparable
AA-SciCodeSource 38.2%Not comparable
Reasoning
BenchmarkClaude Mythos 5Gemma 4 12BResult
BBHSource 53%Not comparable
MRCRv2Source 43.4%Not comparable
AA-LCRSource 55.3%Not comparable
CritPtSource 0.0%Not comparable
KnowledgeGemma 4 12B wins
BenchmarkClaude Mythos 5Gemma 4 12BResult
GPQASource 94.1%78.8%Claude Mythos 5 leads
HLESource 64.5%Not comparable
HLE w/o toolsSource 59%5.2%Claude Mythos 5 leads
GPQA-DSource 78.8%Not comparable
MMLU-ProSource 77.2%Not comparable
MMMLUSource 83.4%Not comparable
Artificial Analysis Intelligence IndexSource 22.0%Not comparable
AA-GPQA DiamondSource 75.3%Not comparable
AA-HLESource 14.8%Not comparable
AA-Omniscience IndexSource -51.9%Not comparable
AA-Omniscience AccuracySource 16.0%Not comparable
AA-Omniscience Hallucination RateSource 80.8%Not comparable
MathClaude Mythos 5 wins
BenchmarkClaude Mythos 5Gemma 4 12BResult
USAMO 2026Source 97.6%Not comparable
AIME26Source 77.5%Not comparable
Multilingual
BenchmarkClaude Mythos 5Gemma 4 12BResult
SWE MultilingualSource 92.2%Not comparable
MultimodalClaude Mythos 5 wins
BenchmarkClaude Mythos 5Gemma 4 12BResult
SWE-bench MultimodalSource 54.9%Not comparable
CharXivSource 93.5%Not comparable
CharXiv w/o toolsSource 88.9%Not comparable
MMMU-ProSource 69.1%Not comparable
MathVisionSource 79.7%Not comparable
MedXpertQA (MM)Source 48.7%Not comparable
AA-MMMU-ProSource 69.7%Not comparable
Inst. Following
BenchmarkClaude Mythos 5Gemma 4 12BResult
AA-IFBenchSource 73.5%Not comparable
Frequently Asked Questions (4)

Which is better, Claude Mythos 5 or Gemma 4 12B?

Claude Mythos 5 is ahead on BenchLM's BenchAlign leaderboard, 83.93 to 47.29. The biggest single separator in this matchup is GPQA, where the scores are 94.1% and 78.8%.

Which is better for knowledge tasks, Claude Mythos 5 or Gemma 4 12B?

Gemma 4 12B has the edge for knowledge tasks in this comparison, averaging 77.5 versus 68.5. Inside this category, HLE w/o tools is the benchmark that creates the most daylight between them.

Which is better for math, Claude Mythos 5 or Gemma 4 12B?

Claude Mythos 5 has the edge for math in this comparison, averaging 97.6 versus 77.5. Gemma 4 12B 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 Gemma 4 12B?

Claude Mythos 5 has the edge for multimodal and grounded tasks in this comparison, averaging 93.5 versus 69.1. Gemma 4 12B stays close enough that the answer can still flip depending on your workload.

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Last updated: July 23, 2026

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