Compare / Claude Fable 5.1 vs Gemini 3.8 Flash
Claude Fable 5.1 vs Gemini 3.8 Flash
36 results from 5 sources that measured both models. Each row is in the source's own units; there is no overall winner.
| Benchmark | Metric | Claude Fable 5.1 | Gemini 3.8 Flash |
|---|---|---|---|
| BulletBenchmeasured by us | Ladder Eloladder Elo | 358 | 1,126 |
| BulletBenchmeasured by us | Median move timemilliseconds | 5.4 s | 4.0 s |
| CatalogBenchmeasured by us | Content quality% of checks | 96.2% | 97.3% |
| CatalogBenchmeasured by us | Failed outputs% of products | 0.0% | 0.0% |
| CatalogBenchmeasured by us | Publish-ready listings% of products | 0.6% | 2.4% |
| CatalogBenchmeasured by us | Reliably publish-ready% of products | 0.0% | 1.8% |
| CatalogBenchmeasured by us | Unsupported claimsclaims per product | 7.91 | 7.12 |
| CatalogBenchmeasured by us | Channel compliance% of products | 100.0% | 98.8% |
| CatalogBenchmeasured by us | Conflicts caught% of conflicts | 100.0% | 100.0% |
| CatalogBenchmeasured by us | Content quality% of checks | 96.3% | 97.1% |
| CatalogBenchmeasured by us | Cost per productUS dollars | $0.0991 | $0.0103 |
| CatalogBenchmeasured by us | Decision accuracy% of decisions | 94.3% | 94.3% |
| CatalogBenchmeasured by us | Failed outputs% of products | 0.0% | 0.0% |
| CatalogBenchmeasured by us | Field accuracy% of missing fields | 94.7% | 92.7% |
| CatalogBenchmeasured by us | Invented values% of filled values | 0.7% | 0.2% |
| CatalogBenchmeasured by us | Publish-ready listings% of products | 35.1% | 33.3% |
| CatalogBenchmeasured by us | Reliably publish-ready% of products | 16.1% | 16.1% |
| CatalogBenchmeasured by us | Unsupported claimsclaims per product | 1.89 | 1.79 |
| ROASBenchmeasured by us | Cost of a runUS dollars | $2.49 | $0.16 |
| ROASBenchmeasured by us | Months over budgetmonths of 12 | 0 | 0 |
| ROASBenchmeasured by us | Overall scorescore out of 100 | 51.5 | 51.4 |
| ROASBenchmeasured by us | Return on ad spendprofit per £1 spent | £0.64 | £0.65 |
| Arena (formerly LMArena)reported | Confirmed task successIPS effect estimate | 0.17 | 0.09 |
| Arena (formerly LMArena)reported | Praise over complaintIPS effect estimate | 0.32 | 0.05 |
| Arena (formerly LMArena)reported | SteerabilityIPS effect estimate | 0.08 | 0.04 |
| Arena (formerly LMArena)reported | Tool groundingIPS effect estimate | 0.00 | 0.00 |
| Arena (formerly LMArena)reported | OverallArena rating | 1,501 | 1,477 |
| Arena (formerly LMArena)reported | Business, management and financeArena rating | 1,485 | 1,482 |
| Arena (formerly LMArena)reported | Creative writingArena rating | 1,484 | 1,482 |
| Arena (formerly LMArena)reported | Expert promptsArena rating | 1,516 | 1,529 |
| Arena (formerly LMArena)reported | Instruction followingArena rating | 1,497 | 1,488 |
| Arena (formerly LMArena)reported | OverallArena rating | 1,501 | 1,492 |
| Arena (formerly LMArena)reported | Writing, literature and languageArena rating | 1,496 | 1,486 |
| UGI Leaderboardreported | Requested-length error% off the requested word count | 3.0% | 13.0% |
| UGI Leaderboardreported | Style adherencescore from 0 to 1 | 0.43 | 0.34 |
| UGI Leaderboardreported | Writing scorescore out of 100 | 63.9 | 78.5 |
Bold green marks the better value on that metric. Where a source reports ranges that overlap, the difference may not be meaningful; see the benchmark page for ranges.