Compare / Claude Opus 5.5 vs Gemini 3.8 Flash
Claude Opus 5.5 vs Gemini 3.8 Flash
35 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 Opus 5.5 | Gemini 3.8 Flash |
|---|---|---|---|
| BulletBenchmeasured by us | Ladder Eloladder Elo | 557 | 1,126 |
| BulletBenchmeasured by us | Median move timemilliseconds | 7.5 s | 4.0 s |
| CatalogBenchmeasured by us | Content quality% of checks | 96.6% | 97.3% |
| CatalogBenchmeasured by us | Failed outputs% of products | 0.0% | 0.0% |
| CatalogBenchmeasured by us | Publish-ready listings% of products | 3.6% | 2.4% |
| CatalogBenchmeasured by us | Reliably publish-ready% of products | 0.0% | 1.8% |
| CatalogBenchmeasured by us | Unsupported claimsclaims per product | 4.36 | 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 | 97.2% | 97.1% |
| CatalogBenchmeasured by us | Cost per productUS dollars | $0.0400 | $0.0103 |
| CatalogBenchmeasured by us | Decision accuracy% of decisions | 96.6% | 94.3% |
| CatalogBenchmeasured by us | Failed outputs% of products | 0.0% | 0.0% |
| CatalogBenchmeasured by us | Field accuracy% of missing fields | 92.2% | 92.7% |
| CatalogBenchmeasured by us | Invented values% of filled values | 0.5% | 0.2% |
| CatalogBenchmeasured by us | Publish-ready listings% of products | 58.3% | 33.3% |
| CatalogBenchmeasured by us | Reliably publish-ready% of products | 39.3% | 16.1% |
| CatalogBenchmeasured by us | Unsupported claimsclaims per product | 0.83 | 1.79 |
| ROASBenchmeasured by us | Cost of a runUS dollars | $1.06 | $0.16 |
| ROASBenchmeasured by us | Months over budgetmonths of 12 | 0 | 0 |
| ROASBenchmeasured by us | Overall scorescore out of 100 | 51.6 | 51.4 |
| ROASBenchmeasured by us | Return on ad spendprofit per £1 spent | £0.69 | £0.65 |
| Arena (formerly LMArena)reported | Confirmed task successIPS effect estimate | 0.16 | 0.09 |
| Arena (formerly LMArena)reported | Praise over complaintIPS effect estimate | 0.19 | 0.05 |
| Arena (formerly LMArena)reported | SteerabilityIPS effect estimate | 0.14 | 0.04 |
| Arena (formerly LMArena)reported | Tool groundingIPS effect estimate | 0.00 | 0.00 |
| Arena (formerly LMArena)reported | Business, management and financeArena rating | 1,499 | 1,482 |
| Arena (formerly LMArena)reported | Creative writingArena rating | 1,521 | 1,482 |
| Arena (formerly LMArena)reported | Expert promptsArena rating | 1,556 | 1,529 |
| Arena (formerly LMArena)reported | Instruction followingArena rating | 1,516 | 1,488 |
| Arena (formerly LMArena)reported | OverallArena rating | 1,509 | 1,492 |
| Arena (formerly LMArena)reported | Writing, literature and languageArena rating | 1,520 | 1,486 |
| UGI Leaderboardreported | Requested-length error% off the requested word count | 2.0% | 13.0% |
| UGI Leaderboardreported | Style adherencescore from 0 to 1 | 0.43 | 0.34 |
| UGI Leaderboardreported | Writing scorescore out of 100 | 70.0 | 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.