Gemini 3.8 Flash vs Composer 2.5
Gemini 3.8 Flash leads overall, C- to D. Composer 2.5 is about 2.7x cheaper per task. By suite, real-world issues is even at C- and Gemini 3.8 Flash takes spec planning (D+ to D). Take Composer 2.5 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: Composer 2.5 vs Gemini 3.8 Flash
Gemini 3.8 Flash leads overall, C- to D. By suite: real-world issues is even at C- (60% vs 57% capability); Gemini 3.8 Flash takes spec planning, D+ to D (50% vs 48% capability); Gemini 3.8 Flash takes vibe coding, C- to F (56% vs 23% capability). Gemini 3.8 Flash used 23.7% of Google AI Pro's weekly limit per pass, $0.057 per task at the listed price. Composer 2.5 used 2.0% of Cursor Pro's monthly limit per pass, $0.021 per task at the listed price. Per task, Composer 2.5 is about 2.7x cheaper ($0.021 vs $0.057). Composer 2.5 is faster on real-world issues: a median task takes 1m 34s against 5m 21s. Both finished every task on it. Reasons to pick Composer 2.5 anyway: it is cheaper per task ($0.021 vs $0.057) and it is faster on real-world issues (1m 34s vs 5m 21s median).
Changed since W39: Gemini 3.8 Flash: real-world issues F to C-, real-world issues usage 18.0% to 21.9% of the weekly limit, spec planning usage 2.0% to 1.8% of the weekly limit, vibe coding D+ to C-, vibe coding usage 1.2% to 1.1% of the weekly limit; Composer 2.5: real-world issues D+ to C-.
| Dimension | Gemini 3.8 Flash | Composer 2.5 | Advantage |
|---|---|---|---|
| Capability | 60% | 57% | +3% (Gemini 3.8 Flash leads) |
| Median task time | 5m 21s | 1m 34s | 3m 46s faster (Composer 2.5 leads) |
| Approx. task cost | $0.067 / task | $0.021 / task | $0.046 / task lower (Composer 2.5 leads) |
Gemini 3.8 Flash: 21.9% of Google AI Pro (131.3% / 5h, 21.9% / 1w) per run. Its weekly limit holds 6 of the week's 33.6 5h windows. Composer 2.5: 1.6% of Cursor Pro (1.6% / 1m) per run. Each figure is a share of that agent's own plan, so there is no delta to draw.
| Dimension | Gemini 3.8 Flash | Composer 2.5 | Advantage |
|---|---|---|---|
| Capability | 50% | 48% | +2% (Gemini 3.8 Flash leads) |
| Median task time | 3m 0s | 1m 8s | 1m 53s faster (Composer 2.5 leads) |
| Approx. task cost | $0.021 / task | $0.022 / task | $0.001 / task lower (Gemini 3.8 Flash leads) |
Gemini 3.8 Flash: 1.8% of Google AI Pro (11.0% / 5h, 1.8% / 1w) per run. Its weekly limit holds 6 of the week's 33.6 5h windows. Composer 2.5: 0.4% of Cursor Pro (0.4% / 1m) per run. Each figure is a share of that agent's own plan, so there is no delta to draw.
| Dimension | Gemini 3.8 Flash | Composer 2.5 | Advantage |
|---|---|---|---|
| Capability | 56% | 23% | +34% (Gemini 3.8 Flash leads) |
| Median task time | 7m 51s | 1m 37s | 6m 14s faster (Composer 2.5 leads) |
| Approx. task cost | $0.048 / task | $0.022 / task | $0.027 / task lower (Composer 2.5 leads) |
Gemini 3.8 Flash: 1.1% of Google AI Pro (6.3% / 5h, 1.1% / 1w) per good solve. Its weekly limit holds 6 of the week's 33.6 5h windows. Composer 2.5: 0.1% of Cursor Pro (0.1% / 1m) per good solve. 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 Composer 2.5?
Gemini 3.8 Flash clears higher: tier 4 of 5 versus tier 1 for Composer 2.5 on real-world@v3, our private suite of real-world coding problems. Latest measurement 2026-09-27.
Which is cheaper per task, Gemini 3.8 Flash or Composer 2.5?
Gemini 3.8 Flash used 23.7% of Google AI Pro's weekly limit per pass, $0.057 per task at the listed price. Composer 2.5 used 2.0% of Cursor Pro's monthly limit per pass, $0.021 per task at the listed price. Per task, Composer 2.5 is about 2.7x cheaper ($0.021 vs $0.057).