Gemini 3.8 Flash vs Claude Opus 5.5
Claude Opus 5.5 leads overall, C+ to D. Claude Opus 5.5 is about 4.0x cheaper per task. By suite, Claude Opus 5.5 takes real-world issues (C- to F) and spec planning (C+ to D+). The data gives no reason to pick Gemini 3.8 Flash over Claude Opus 5.5 this week.Measured
Each agent graded on the same private suites, running headless through its own tools. Advantages are oriented so a win is a win, whichever way the metric runs.
Verdict: Claude Opus 5.5 vs Gemini 3.8 Flash
Claude Opus 5.5 leads overall, C+ to D. By suite: Claude Opus 5.5 takes real-world issues, C- to F (60% vs 28% capability); Claude Opus 5.5 takes spec planning, C+ to D+ (69% vs 50% capability); Claude Opus 5.5 takes vibe coding, B to D+ (85% vs 52% capability). Gemini 3.8 Flash used 19.9% of Google AI Pro's weekly limit per pass, $0.048 per task at the listed price. Claude Opus 5.5 used 1% of Claude Max 5x's weekly limit per pass, $0.012 per task at the listed price. Per task, Claude Opus 5.5 is about 4.0x cheaper ($0.012 vs $0.048). Claude Opus 5.5 is faster on real-world issues: a median task takes 2m 18s against 3m 11s. Both finished every task on it. The data gives no reason to pick Gemini 3.8 Flash over Claude Opus 5.5 this week.
Changed since W38: Gemini 3.8 Flash: real-world issues D+ to F, real-world issues usage 18.4% to 18.0% of the weekly limit, spec planning D to D+, spec planning usage 1.7% to 2.0% of the weekly limit, vibe coding C- to D+, vibe coding usage 1.0% to 1.2% of the weekly limit.
| Dimension | Gemini 3.8 Flash | Claude Opus 5.5 | Advantage |
|---|---|---|---|
| Capability | 28% | 60% | +32% (Claude Opus 5.5 leads) |
| Median task time | 3m 11s | 2m 18s | 53s faster (Claude Opus 5.5 leads) |
| Approx. task cost | $0.055 / task | $0.015 / task | $0.040 / task lower (Claude Opus 5.5 leads) |
Gemini 3.8 Flash: 18.0% of Google AI Pro (107.8% / 5h, 18.0% / 1w) per run. Its weekly limit holds 6 of the week's 33.6 5h windows. Claude Opus 5.5: 16.0% of Claude Max 5x (16.0% / 5h, 1.0% / 1w) per run. Its weekly limit holds about 14.6 of the week's 33.6 5h windows. Each figure is a share of that agent's own plan, so there is no delta to draw.
| Dimension | Gemini 3.8 Flash | Claude Opus 5.5 | Advantage |
|---|---|---|---|
| Capability | 50% | 69% | +19% (Claude Opus 5.5 leads) |
| Median task time | 2m 23s | 3m 45s | 1m 22s faster (Gemini 3.8 Flash leads) |
| Approx. task cost | $0.023 / task | $0.010 / task | $0.012 / task lower (Claude Opus 5.5 leads) |
Gemini 3.8 Flash: 2.0% of Google AI Pro (11.7% / 5h, 2.0% / 1w) per run. Its weekly limit holds 6 of the week's 33.6 5h windows. Claude Opus 5.5: 6.0% of Claude Max 5x (6.0% / 5h) per run. Its weekly limit holds about 14.6 of the week's 33.6 5h windows. Each figure is a share of that agent's own plan, so there is no delta to draw.
| Dimension | Gemini 3.8 Flash | Claude Opus 5.5 | Advantage |
|---|---|---|---|
| Capability | 52% | 85% | +32% (Claude Opus 5.5 leads) |
| Median task time | 6m 42s | 2m 27s | 4m 15s faster (Claude Opus 5.5 leads) |
| Approx. task cost | $0.054 / task | $0.046 / task | $0.008 / task lower (Claude Opus 5.5 leads) |
Gemini 3.8 Flash: 1.2% of Google AI Pro (7.0% / 5h, 1.2% / 1w) per good solve. Its weekly limit holds 6 of the week's 33.6 5h windows. Claude Opus 5.5: 0.8% of Claude Max 5x (0.8% / 5h, 0.2% / 1w) per good solve. Its weekly limit holds about 14.6 of the week's 33.6 5h windows. Each figure is a share of that agent's own plan, so there is no delta to draw.
Grades and deltas are comparable only within a suite version. See methodology.
Frequently asked questions
Which is better for coding, Gemini 3.8 Flash or Claude Opus 5.5?
Claude Opus 5.5 clears higher: tier 4 of 5 versus tier 0 for Gemini 3.8 Flash on real-world@v3, our private suite of real-world coding problems. Latest measurement 2026-09-20.
Which is cheaper per task, Gemini 3.8 Flash or Claude Opus 5.5?
Gemini 3.8 Flash used 19.9% of Google AI Pro's weekly limit per pass, $0.048 per task at the listed price. Claude Opus 5.5 used 1% of Claude Max 5x's weekly limit per pass, $0.012 per task at the listed price. Per task, Claude Opus 5.5 is about 4.0x cheaper ($0.012 vs $0.048).