Comparing 2 models
Claude Fable 5.1 vs Gemini 3.8 Flash
Benchmarks through
Verdict
Gemini 3.8 Flash places higher on 17 of the 21 tasks where both are ranked. Gemini 3.8 Flash costs 12.1x less per input token. Gemini 3.8 Flash accepts 1.0x more context.
- Choose Claude Fable 5.1 for Massive Context (#1), Computer & Browser Use (#3), Grounded RAG (#4).
- Choose Gemini 3.8 Flash for Creative Writing (#1), Translation (#1), Charts & Diagrams (#1).
Built from the published task rankings below; ranks come from each task's own weighted benchmarks, so a win on one task says nothing about another.
Measured head to head
Benchmarks both models were run on
| Evaluation | Claude Fable 5.1 | Gemini 3.8 Flash | Source |
|---|---|---|---|
| Design Arena Coding | 1338 Elo | 1306 Elo | source · 2026-10-16 |
| Design Arena Full-stack Agent | 1326 Elo | 1244 Elo | source · 2026-10-14 |
| Design Arena UI | 1338 Elo | 1319 Elo | source · 2026-10-16 |
| Design Arena Web-app Agent | 1311 Elo | 1231 Elo | source · 2026-10-14 |
| Design Arena Website | 1314 Elo | 1303 Elo | source · 2026-10-16 |
| FrontierMath Tiers 1-3 (Epoch AI) | 90.2% ± 1.8 | 68.4% ± 2.8 | source · 2026-09-01 |
| LiveBench Agentic Coding | 66.1% | 54.2% | source · 2026-10-16 |
| LiveBench Coding | 86.4% | 72.5% | source · 2026-10-16 |
| LiveBench Data Analysis | 80.3% | 54.0% | source · 2026-10-16 |
| LiveBench Instruction Following | 73.0% | 81.4% | source · 2026-10-16 |
| LiveBench Language | 89.5% | 87.8% | source · 2026-10-16 |
| LiveBench Math | 97.0% | 91.6% | source · 2026-10-16 |
| LiveBench Reasoning | 91.7% | 89.3% | source · 2026-10-16 |
| LMArena Agent | 14.1 | 4 | source · 2026-10-14 |
| LMArena Agent Bash Recovery | 11.6 | -0.7 | source · 2026-10-08 |
| LMArena Agent Steerability | 14.7 | 2.1 | source · 2026-10-14 |
| LMArena Agent Task Outcome | 15.7 | 5.1 | source · 2026-10-14 |
| LMArena Agent Tool Hallucination | 0.6 | 0.5 | source · 2026-10-14 |
| LMArena Creative Writing | 1508 Elo | 1492 Elo | source · 2026-10-15 |
| LMArena Instruction Following | 1517 Elo | 1491 Elo | source · 2026-10-15 |
| LMArena Long Query | 1523 Elo | 1507 Elo | source · 2026-10-15 |
| LMArena Math | 1528 Elo | 1527 Elo | source · 2026-10-15 |
| LMArena Text | 1502 Elo | 1496 Elo | source · 2026-10-15 |
| LMArena Text Factuality | 1498 Elo | 1474 Elo | source · 2026-10-15 |
| LMArena Vision | 1286 Elo | 1289 Elo | source · 2026-10-09 |
| LMArena Vision Diagrams | 1326 Elo | 1333 Elo | source · 2026-10-09 |
| LMArena Vision OCR | 1302 Elo | 1317 Elo | source · 2026-10-09 |
| LMArena WebDev | 1743 Elo | 1585 Elo | source · 2026-10-13 |
| LMArena WebDev Image-to-Web | 1720 Elo | 1593 Elo | source · 2026-10-09 |
| OTIS Mock AIME (Epoch AI) | 100% ± 0 | 98.9% ± 0.9 | source · 2026-09-01 |
| SimpleQA Verified (Epoch AI) | 70.8% ± 1.4 | 69.7% ± 1.5 | source · 2026-09-01 |
| Terminal-Bench (4.0) | 57.9% | 19.1% | source · 2026-10-16 |
Values are as published by each evaluator, in its own units; rows from different evaluators are not on a common scale.
task evidence
How they place when the question changes
Lower ranks are better. “Best” marks the strongest option in this shortlist for that task.