Gemini 3.1 Pro vs Claude Sonnet 5.5
Claude Sonnet 5.5 leads overall, C- to F. Claude Sonnet 5.5 is about 13x cheaper per task. By suite, Claude Sonnet 5.5 takes real-world issues (C- to D+) and spec planning (C+ to F). The data gives no reason to pick Gemini 3.1 Pro over Claude Sonnet 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 Sonnet 5.5 vs Gemini 3.1 Pro
Claude Sonnet 5.5 leads overall, C- to F. By suite: Claude Sonnet 5.5 takes real-world issues, C- to D+ (60% vs 53% capability); Claude Sonnet 5.5 takes spec planning, C+ to F (74% vs 21% capability); Claude Sonnet 5.5 takes vibe coding, D+ to F (48% vs 27% capability). Gemini 3.1 Pro used 15.9% of Google AI Pro's weekly limit per pass, $0.038 per task at the listed price. Claude Sonnet 5.5 used <1% of Claude Max 5x's weekly limit per pass, $0.003 per task at the listed price. Per task, Claude Sonnet 5.5 is about 13x cheaper ($0.003 vs $0.038). Claude Sonnet 5.5 is faster on real-world issues: a median task takes 37s against 4m 53s. Both finished every task on it. The data gives no reason to pick Gemini 3.1 Pro over Claude Sonnet 5.5 this week.
Changed since W39: Gemini 3.1 Pro: real-world issues usage 9.8% to 14.8% of the weekly limit, spec planning usage 0.9% to 1.1% of the weekly limit, vibe coding usage 1.0% to 0.7% of the weekly limit.
| Dimension | Gemini 3.1 Pro | Claude Sonnet 5.5 | Advantage |
|---|---|---|---|
| Capability | 53% | 60% | +7% (Claude Sonnet 5.5 leads) |
| Median task time | 4m 53s | 37s | 4m 16s faster (Claude Sonnet 5.5 leads) |
| Approx. task cost | $0.045 / task | $0.002 / task | $0.044 / task lower (Claude Sonnet 5.5 leads) |
Gemini 3.1 Pro: 14.8% of Google AI Pro (88.9% / 5h, 14.8% / 1w) per run. Its weekly limit holds 6 of the week's 33.6 5h windows. Claude Sonnet 5.5: 4.0% of Claude Max 5x (4.0% / 5h) 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.
| Dimension | Gemini 3.1 Pro | Claude Sonnet 5.5 | Advantage |
|---|---|---|---|
| Capability | 21% | 74% | +53% (Claude Sonnet 5.5 leads) |
| Median task time | 1m 46s | 3m 25s | 1m 39s faster (Gemini 3.1 Pro leads) |
| Approx. task cost | $0.013 / task | $0.007 / task | $0.006 / task lower (Claude Sonnet 5.5 leads) |
Gemini 3.1 Pro: 1.1% of Google AI Pro (6.5% / 5h, 1.1% / 1w) per run. Its weekly limit holds 6 of the week's 33.6 5h windows. Claude Sonnet 5.5: 4.0% of Claude Max 5x (4.0% / 5h) 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.
| Dimension | Gemini 3.1 Pro | Claude Sonnet 5.5 | Advantage |
|---|---|---|---|
| Capability | 27% | 48% | +21% (Claude Sonnet 5.5 leads) |
| Median task time | 4m 38s | 56s | 3m 41s faster (Claude Sonnet 5.5 leads) |
| Approx. task cost | $0.034 / task | $0.001 / task | $0.033 / task lower (Claude Sonnet 5.5 leads) |
Gemini 3.1 Pro: 0.7% of Google AI Pro (4.4% / 5h, 0.7% / 1w) per good solve. Its weekly limit holds 6 of the week's 33.6 5h windows. Claude Sonnet 5.5: 0.2% of Claude Max 5x (0.2% / 5h) 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 3.1 Pro or Claude Sonnet 5.5?
Claude Sonnet 5.5 clears higher: tier 4 of 5 versus tier 3 for Gemini 3.1 Pro on real-world@v3, our private suite of real-world coding problems. Latest measurement 2026-09-28.
Which is cheaper per task, Gemini 3.1 Pro or Claude Sonnet 5.5?
Gemini 3.1 Pro used 15.9% of Google AI Pro's weekly limit per pass, $0.038 per task at the listed price. Claude Sonnet 5.5 used <1% of Claude Max 5x's weekly limit per pass, $0.003 per task at the listed price. Per task, Claude Sonnet 5.5 is about 13x cheaper ($0.003 vs $0.038).