Gemini 3.6 Flash vs Claude Fable 5.1
Gemini 3.6 Flash was superseded by Gemini 3.8 Flash. The grades below are the last ones measured, so read them as history rather than as this week's board. See the current roster.
Claude Fable 5.1 leads overall, B- to C. Gemini 3.6 Flash is about 2.5x cheaper per task. By suite, Claude Fable 5.1 takes real-world issues (B+ to C-) and vibe coding is even at C+. Take Gemini 3.6 Flash anyway when you want the side that is cheaper per task and faster on real-world issues.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 Fable 5.1 vs Gemini 3.6 Flash
Claude Fable 5.1 leads overall, B- to C. By suite: Claude Fable 5.1 takes real-world issues, B+ to C- (87% vs 60% capability); vibe coding is even at C+ (72% vs 74% capability). Only Claude Fable 5.1 has run spec planning. Gemini 3.6 Flash used 12.6% of Google AI Pro's weekly limit per pass, $0.039 per task at the listed price. Claude Fable 5.1 used 8% of Claude Max 5x's weekly limit per pass, $0.097 per task at the listed price. Per task, Gemini 3.6 Flash is about 2.5x cheaper ($0.039 vs $0.097). Gemini 3.6 Flash is faster on real-world issues: a median task takes 2m 17s against 3m 38s. Both finished every task on it. Reasons to pick Gemini 3.6 Flash anyway: it is cheaper per task ($0.039 vs $0.097) and it is faster on real-world issues (2m 17s vs 3m 38s median).
Changed since the previous graded week: Gemini 3.6 Flash unchanged; Claude Fable 5.1: real-world issues D+ to B+, real-world issues usage 7% to 5% of the weekly limit, spec planning usage 4% to 3% of the weekly limit, vibe coding C- to C+, vibe coding usage 0.6% to 0.4% of the weekly limit.
| Dimension | Gemini 3.6 Flash | Claude Fable 5.1 | Advantage |
|---|---|---|---|
| Capability | 60% | 87% | +27% (Claude Fable 5.1 leads) |
| Median task time | 2m 17s | 3m 38s | 1m 21s faster (Gemini 3.6 Flash leads) |
| Approx. task cost | $0.039 / task | $0.077 / task | $0.038 / task lower (Gemini 3.6 Flash leads) |
Gemini 3.6 Flash: 12.6% of Google AI Pro (about 72.1% / 5h, 12.6% / 1w) per run. Its weekly limit holds 6 of the week's 33.6 5h windows. Claude Fable 5.1: 64.0% of Claude Max 5x (64.0% / 5h, 5.0% / 1w) per run. Its weekly limit holds about 13.8 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.
Only Claude Fable 5.1 has run this suite, so there is no head-to-head yet.
| Dimension | Gemini 3.6 Flash | Claude Fable 5.1 | Advantage |
|---|---|---|---|
| Capability | 72% | 74% | +3% (Claude Fable 5.1 leads) |
| Median task time | 1m 54s | 4m 14s | 2m 20s faster (Gemini 3.6 Flash leads) |
| Approx. task cost | $0.038 / task | $0.092 / task | $0.054 / task lower (Gemini 3.6 Flash leads) |
Gemini 3.6 Flash: 0.8% of Google AI Pro (4.9% / 5h, 0.8% / 1w) per good solve. Its weekly limit holds 6 of the week's 33.6 5h windows. Claude Fable 5.1: 4.2% of Claude Max 5x (4.2% / 5h, 0.4% / 1w) per good solve. Its weekly limit holds about 13.8 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 3.6 Flash or Claude Fable 5.1?
Both clear tier 4 of 5, but Claude Fable 5.1 scores higher on capability: 87% versus 60% on real-world@v3, our private suite of real-world coding problems. Latest measurement 2026-08-10.
Which is cheaper per task, Gemini 3.6 Flash or Claude Fable 5.1?
Gemini 3.6 Flash used 12.6% of Google AI Pro's weekly limit per pass, $0.039 per task at the listed price. Claude Fable 5.1 used 8% of Claude Max 5x's weekly limit per pass, $0.097 per task at the listed price. Per task, Gemini 3.6 Flash is about 2.5x cheaper ($0.039 vs $0.097).