Model comparison
Claude Mythos Preview vs Gemini 3.5 Flash
Gemini 3.5 Flash has enough public results to be ranked (#29); Claude Mythos Preview does not yet, so treat this comparison as directional.
Last verified . 0 shared benchmarks.
GoogleSummary
- The widest gap is in agentic & tool use, where Claude Mythos Preview leads 41.1 to 24.8.
Side by side
| Claude Mythos Preview | Gemini 3.5 Flash | |
|---|---|---|
| Provider | Anthropic | |
| Noometry Index | 40.8 | 54.1 |
| Released | 2026-04-07 | 2026-05-19 |
| Weights | Proprietary | Proprietary |
| Context window | — | 1.05M |
| Max output | — | 66K |
| Input $ / M tokens | — | $1.50 |
| Output $ / M tokens | — | $9 |
| Results tracked | 2 | 54 |
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Category by category
Coding Not comparable
Claude Mythos Preview: —, Gemini 3.5 Flash: 49.1 (#46)
| Benchmark | Claude Mythos Preview | Gemini 3.5 Flash |
|---|---|---|
| SWE-bench Verified | — | 79.3% |
| DeepSWE | — | 37.4% |
| LMArena WebDev | — | 1499 |
| SciCode | — | 53.1% |
| WeirdML | — | 62.6% |
| LMArena Coding | — | 1492 |
| ALE-Bench | — | 911.02 |
Agentic & Tool Use Claude Mythos Preview leads
Claude Mythos Preview: 41.1, Gemini 3.5 Flash: 24.8 (#107)
| Benchmark | Claude Mythos Preview | Gemini 3.5 Flash |
|---|---|---|
| APEX-Agents | — | 27.5% |
| ExploitBench | 73.8% | — |
| GBAEval | — | 6.7% |
| GDP.pdf | — | 14% |
| METR Time Horizons | 85.2% | — |
| Vending-Bench 2 | — | 5,396 |
Reasoning Not comparable
Claude Mythos Preview: —, Gemini 3.5 Flash: 62.7 (#16)
| Benchmark | Claude Mythos Preview | Gemini 3.5 Flash |
|---|---|---|
| ARC-AGI-2 | — | 72.1% |
| SimpleBench | — | 76.7% |
| NYT Connections (extended) | — | 92.6% |
| ARC-AGI-1 | — | 92.5% |
| CritPt | — | 13.1% |
| Chess Puzzles | — | 50% |
| EnigmaEval | — | 25.4% |
| EBR-Bench | — | 4.8% |
| LMArena Hard Prompts | — | 1488 |
| Mystery Game Puzzles | — | 32% |
| DTBench | — | 94.7% |
| LMCA | — | 47.1% |
| Surface Evolver Bench | — | 58.1% |
| Epoch Capabilities Index | — | 154.55 |
| ForecastBench | — | 59 |
Math Not comparable
Claude Mythos Preview: —, Gemini 3.5 Flash: 60.5 (#30)
| Benchmark | Claude Mythos Preview | Gemini 3.5 Flash |
|---|---|---|
| FrontierMath (Tiers 1-3) | — | 62.8% |
| FrontierMath Tier 4 | — | 26.8% |
| MathArena Final-Answer Competitions | — | 76.3% |
| OTIS Mock AIME 2024-2025 | — | 95.6% |
| ProofBench | — | 31% |
| LMArena Math | — | 1502 |
| FrontierMath (Feb 2025 set) | — | 39% |
| FrontierMath Tier 4 (v1) | — | 14.6% |
Knowledge Not comparable
Claude Mythos Preview: —, Gemini 3.5 Flash: 66.3 (#10)
| Benchmark | Claude Mythos Preview | Gemini 3.5 Flash |
|---|---|---|
| GPQA Diamond | — | 92.8% |
| SimpleQA Verified | — | 66.2% |
| LMArena Expert | — | 1493 |
Multimodal Not comparable
Claude Mythos Preview: —, Gemini 3.5 Flash: 45.7 (#13)
| Benchmark | Claude Mythos Preview | Gemini 3.5 Flash |
|---|---|---|
| LMArena Vision | — | 1311 |
| Blueprint-Bench 2 | — | 33.6% |
| LMArena Document | — | 1463 |
Multilingual Not comparable
Claude Mythos Preview: —, Gemini 3.5 Flash: 57.1 (#12)
| Benchmark | Claude Mythos Preview | Gemini 3.5 Flash |
|---|---|---|
| LMArena Non-English | — | 1475 |
| LMArena Chinese | — | 1525 |
| LMArena French | — | 1490 |
| LMArena German | — | 1500 |
| LMArena Japanese | — | 1481 |
| LMArena Korean | — | 1453 |
| LMArena Russian | — | 1491 |
| LMArena Spanish | — | 1478 |
Instruction Following Not comparable
Claude Mythos Preview: —, Gemini 3.5 Flash: 77.2 (#29)
| Benchmark | Claude Mythos Preview | Gemini 3.5 Flash |
|---|---|---|
| LMArena Instruction Following | — | 1466 |
Long Context Not comparable
Claude Mythos Preview: —, Gemini 3.5 Flash: 45.3 (#39)
| Benchmark | Claude Mythos Preview | Gemini 3.5 Flash |
|---|---|---|
| LMArena Longer Query | — | 1481 |
Writing & Preference Not comparable
Claude Mythos Preview: —, Gemini 3.5 Flash: 65.5 (#46)
| Benchmark | Claude Mythos Preview | Gemini 3.5 Flash |
|---|---|---|
| LMArena Text | — | 1481 |
| LMArena Creative Writing | — | 1467 |
| EQ-Bench 4 | — | 1087 |
| LMArena Multi-Turn | — | 1482 |
Frequently asked questions
Is Claude Mythos Preview better than Gemini 3.5 Flash?
Gemini 3.5 Flash has enough public results to be ranked (#29); Claude Mythos Preview does not yet, so treat this comparison as directional.
How many benchmarks do Claude Mythos Preview and Gemini 3.5 Flash share?
0 benchmarks have published results for both models. Claude Mythos Preview has 2 scored results on Noometry and Gemini 3.5 Flash has 54.