Noometry

Model comparison

Claude Mythos Preview vs Gemini 3.8 Flash

Gemini 3.8 Flash has enough public results to be ranked (#11); Claude Mythos Preview does not yet, so treat this comparison as directional.

Last verified . 0 shared benchmarks.

Claude Mythos Preview Anthropic

41.2

Unranked Sparse

Gemini 3.8 Flash Google

61.8

Rank #11 Confirmed

Side by side

Claude Mythos PreviewGemini 3.8 Flash
ProviderAnthropicGoogle
Noometry Index41.261.8
Released2026-04-072026-09-02
WeightsProprietaryProprietary
Context window—1.05M
Max output—66K
Input $ / M tokens—$0.75
Output $ / M tokens—$3.75
Results tracked250

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Category by category

Coding Not comparable

Claude Mythos Preview: —, Gemini 3.8 Flash: 59.2 (#15)

BenchmarkClaude Mythos PreviewGemini 3.8 Flash
DeepSWE—73.8%
FrontierCode—41.2%
CursorBench—39.6%
LMArena WebDev—1584
FrontierSWE—19.6%
SciCode—56.6%
WeirdML—84.8%
LMArena Coding—1510
ALE-Bench—1,270

Agentic & Tool Use Too close to call

Claude Mythos Preview: 41.4, Gemini 3.8 Flash: 41.8 (#21)

BenchmarkClaude Mythos PreviewGemini 3.8 Flash
APEX-Agents—64.3%
Remote Labor Index—5.8%
ExploitBench73.8%—
GDP.pdf—23.4%
METR Time Horizons85.2%—
Vending-Bench 2—5,094

Reasoning Not comparable

Claude Mythos Preview: —, Gemini 3.8 Flash: 76.9 (#5)

BenchmarkClaude Mythos PreviewGemini 3.8 Flash
ARC-AGI-2—89.2%
NYT Connections (extended)—97.4%
ARC-AGI-1—98.5%
CritPt—18.3%
Chess Puzzles—61%
LMArena Hard Prompts—1508
Mystery Game Puzzles—47%
DTBench—95.7%
LMCA—52.9%
Surface Evolver Bench—76.9%
Epoch Capabilities Index—156.71

Math Not comparable

Claude Mythos Preview: —, Gemini 3.8 Flash: 65.3 (#28)

BenchmarkClaude Mythos PreviewGemini 3.8 Flash
FrontierMath (Tiers 1-3)—68.4%
FrontierMath Tier 4—22%
OTIS Mock AIME 2024-2025—98.9%
ProofBench—48%
LMArena Math—1528

Knowledge Not comparable

Claude Mythos Preview: —, Gemini 3.8 Flash: 74.8 (#2)

BenchmarkClaude Mythos PreviewGemini 3.8 Flash
GPQA Diamond—95.4%
Humanity's Last Exam—44.5%
SimpleQA Verified—69.7%
LMArena Expert—1524

Multimodal Not comparable

Claude Mythos Preview: —, Gemini 3.8 Flash: 40.7 (#45)

BenchmarkClaude Mythos PreviewGemini 3.8 Flash
LMArena Vision—1314
Blueprint-Bench 2—38.6%
Furniture Assembly—31.7%

Multilingual Not comparable

Claude Mythos Preview: —, Gemini 3.8 Flash: 58.0 (#5)

BenchmarkClaude Mythos PreviewGemini 3.8 Flash
LMArena Non-English—1491
LMArena Chinese—1554
LMArena French—1498
LMArena German—1493
LMArena Japanese—1502
LMArena Korean—1459
LMArena Russian—1515
LMArena Spanish—1485

Instruction Following Not comparable

Claude Mythos Preview: —, Gemini 3.8 Flash: 78.0 (#13)

BenchmarkClaude Mythos PreviewGemini 3.8 Flash
LMArena Instruction Following—1490

Long Context Not comparable

Claude Mythos Preview: —, Gemini 3.8 Flash: 46.3 (#24)

BenchmarkClaude Mythos PreviewGemini 3.8 Flash
LMArena Longer Query—1508

Writing & Preference Not comparable

Claude Mythos Preview: —, Gemini 3.8 Flash: 72.2 (#15)

BenchmarkClaude Mythos PreviewGemini 3.8 Flash
LMArena Text—1499
LMArena Creative Writing—1492
EQ-Bench Creative Writing—1748
LMArena Multi-Turn—1501

Frequently asked questions

Is Claude Mythos Preview better than Gemini 3.8 Flash?

Gemini 3.8 Flash has enough public results to be ranked (#11); Claude Mythos Preview does not yet, so treat this comparison as directional.

How many benchmarks do Claude Mythos Preview and Gemini 3.8 Flash share?

0 benchmarks have published results for both models. Claude Mythos Preview has 2 scored results on Noometry and Gemini 3.8 Flash has 50.

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