Gemini 3.8 Flash vs Claude Fable 5.1
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.
| Dimension | Gemini 3.8 Flash | Claude Fable 5.1 | Advantage |
|---|---|---|---|
| Capability | 53% | 73% | +20% (Claude Fable 5.1 leads) |
| Median task time | 4m 14s | 1m 46s | 2m 28s faster (Claude Fable 5.1 leads) |
| Approx. task cost | $0.063 / task | $0.026 / task | $0.037 / task lower (Claude Fable 5.1 leads) |
Gemini 3.8 Flash: 20.4% of Google AI Pro (122.4% / 5h, 20.4% / 1w) per run. Its weekly limit holds 6 of the week's 33.6 5h windows. Claude Fable 5.1: 28.0% of Claude Max 20x (28.0% / 5h, 5.0% / 1w) per run. Its weekly limit holds about 7.2 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 Fable 5.1 | Advantage |
|---|---|---|---|
| Capability | 39% | 74% | +36% (Claude Fable 5.1 leads) |
| Median task time | 2m 39s | 6m 51s | 4m 12s faster (Gemini 3.8 Flash leads) |
| Approx. task cost | $0.022 / task | $0.051 / task | $0.029 / task lower (Gemini 3.8 Flash leads) |
Gemini 3.8 Flash: 1.9% of Google AI Pro (11.7% / 5h, 1.9% / 1w) per run. Its weekly limit holds 6 of the week's 33.6 5h windows. Claude Fable 5.1: 15.0% of Claude Max 20x (15.0% / 5h, 2.0% / 1w) per run. Its weekly limit holds about 7.2 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 Fable 5.1 | Advantage |
|---|---|---|---|
| Capability | 52% | 85% | +32% (Claude Fable 5.1 leads) |
| Median task time | 7m 7s | 3m 48s | 3m 19s faster (Claude Fable 5.1 leads) |
| Approx. task cost | $0.046 / task | $0.025 / task | $0.021 / task lower (Claude Fable 5.1 leads) |
Gemini 3.8 Flash: 1.0% of Google AI Pro (6.0% / 5h, 1.0% / 1w) per good solve. Its weekly limit holds 6 of the week's 33.6 5h windows. Claude Fable 5.1: 1.8% of Claude Max 20x (1.8% / 5h, 0.2% / 1w) per good solve. Its weekly limit holds about 7.2 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 Fable 5.1?
Claude Fable 5.1 clears higher: tier 4 of 5 versus tier 3 for Gemini 3.8 Flash on real-world@v3, our private suite of real-world coding problems. Latest measurement 2026-09-02.