Claude Opus 5.5 vs Gemini 3.8 Flash
On the 35 use cases both models ran, Claude Opus 5.5 won 34 to 1 (better outcome first, then lower cost).
Pass rate: Claude Opus 5.5 97% (35 runs) vs Gemini 3.8 Flash 97% (35 runs). Average cost per run: $0.17 vs $0.35.
| Metric | Claude Opus 5.5 | Gemini 3.8 Flash |
|---|---|---|
| Runs on shared use cases | 35 | 35 |
| Pass rate | 97% (34/35) | 97% (34/35) |
| Avg cost per run | $0.17 | $0.35 |
| Avg wall time | 40s | 4m |
| Step-ins per run | 0.17 | 0.17 |
| Use cases won | 34 | 1 |
Use case by use case
- AIS collision risk: closest point of approach and alert levels: Claude Opus 5.5 better (pass 100% vs 100%)
- Anchor drag alarm from a GPS track: Claude Opus 5.5 better (pass 100% vs 100%)
- Animate a fish tank with swimming fish and rising bubbles in one self-contained HTML file: Claude Opus 5.5 better (pass 100% vs 100%)
- Animate a flickering carved pumpkin on a spooky night in one self-contained HTML file: Claude Opus 5.5 better (pass 100% vs 100%)
- Animate a junction where cars obey a traffic light's timed sequence in one self-contained HTML file: Claude Opus 5.5 better (pass 100% vs 100%)
- Animate a metronome that ticks a repeating two-tempo pattern in one self-contained HTML file: Claude Opus 5.5 better (pass 100% vs 100%)
- Animate a row of pendulums, each swinging at its own true period, in one self-contained HTML file: Claude Opus 5.5 better (pass 100% vs 100%)
- Animate a snow globe that a click shakes, with snow that settles again, in one self-contained HTML file: Claude Opus 5.5 better (pass 100% vs 100%)
- Animate balls dropped onto a floor that bounce with real gravity and restitution in one self-contained HTML file: Claude Opus 5.5 better (pass 100% vs 100%)
- Animate hot-air balloons drifting over hills at sunrise in one self-contained HTML file: Claude Opus 5.5 better (pass 100% vs 100%)
- Animate planets orbiting the sun at their own speeds in one self-contained HTML file: Claude Opus 5.5 better (pass 100% vs 100%)
- Animate rain running down a window over blurred city lights in one self-contained HTML file: Claude Opus 5.5 better (pass 100% vs 100%)
- Assign a community transport scheme's volunteer driver trips when one driver's background-check status is blank: Claude Opus 5.5 better (pass 100% vs 100%)
- Best fishing windows from tide, solunar and weather data: Claude Opus 5.5 better (pass 100% vs 100%)
- Best sailing angle and leg times from a polar table: Claude Opus 5.5 better (pass 100% vs 100%)
- Bill a hotel's group bookings across a mid-month rate rise, weekend nights, cancellations with time-zone offsets and a city-tax cap: Claude Opus 5.5 better (pass 100% vs 100%)
- Boat fuel range with a reserve over a planned trip: Claude Opus 5.5 better (pass 100% vs 100%)
- Catch log checked against a made-up fishing regulations table: Claude Opus 5.5 better (pass 100% vs 100%)
- Charge residents' parking permits by emission band, part year, household order and blue-badge exemption: Claude Opus 5.5 better (pass 100% vs 100%)
- Check and pay staff mileage claims across the April tax-year change: Claude Opus 5.5 better (pass 100% vs 100%)
- Dead reckoning, estimated position with current, and computed set and drift: Claude Opus 5.5 better (pass 100% vs 100%)
- Diagnose why GitHub Actions stopped running: Claude Opus 5.5 better (pass 100% vs 100%)
- Draw a ticking, styled analog clock that shows the current time in one self-contained HTML file: Claude Opus 5.5 better (pass 100% vs 100%)
- Draw a walking pixel-art character sprite animation in one self-contained HTML file: Claude Opus 5.5 better (pass 100% vs 100%)
- Enrol children on a leisure centre's swimming lessons when one child has a medical alert on file this term: Claude Opus 5.5 better (pass 100% vs 100%)
- Fix three bugs in a Python repo so its tests pass: Claude Opus 5.5 better (pass 100% vs 100%)
- Go/no-go departure time from a gridded wind file: Claude Opus 5.5 better (pass 100% vs 100%)
- Let a town's allotment plots when one tenant still has a rent-arrears row this year: Claude Opus 5.5 better (pass 100% vs 0%)
- Sailboat instrument dashboard from an NMEA 0183 log: Claude Opus 5.5 better (pass 100% vs 100%)
- Schedule a pharmacy's home deliveries when one parcel holds a medicine missing from the delivery list: Gemini 3.8 Flash better (pass 0% vs 100%)
- Tide height by rule of twelfths and cosine, with under-keel clearance windows: Claude Opus 5.5 better (pass 100% vs 100%)
- Water-quality sensor anomaly flags and daily means: Claude Opus 5.5 better (pass 100% vs 100%)
- Work out a care home's fortnightly pay from shifts that span the night the clocks go back: Claude Opus 5.5 better (pass 100% vs 100%)
- Work out a library's overdue fines from loans, renewals, closed days and member categories: Claude Opus 5.5 better (pass 100% vs 100%)
- Work out late-payment interest and compensation from part payments, credit notes and a base-rate change: Claude Opus 5.5 better (pass 100% vs 100%)
Only use cases both models ran are compared; all settings of each model are grouped. How we score.