Compare / Gemini 3.1 Pro Preview vs Mercury 3
Gemini 3.1 Pro Preview vs Mercury 3
Which is cheaper, which is more capable, and which does better at each kind of work, from 51 results on 4 sources that measured both models.
Of the 51 results both models have, the better value on each. Results whose reported ranges overlap are too close to call.
Results as of 20 October 2026 (catalogue release 2026-10-20-96eb40c3ec63).
Gemini 3.1 Pro Preview or Mercury 3? The short answer
Pick Gemini 3.1 Pro Preview if quality matters most: it scores higher (Spring Prompt overall 48 against 39). Pick Mercury 3 if cost matters more: it costs 12 times less per deck on DeckBench.
- Spring Prompt overall: Gemini 3.1 Pro Preview 48, Mercury 3 39 (out of 100; how the score works).
- Mercury 3 is cheaper to run: $0.012 against $0.14 per deck on DeckBench (12 times less).
- Mercury 3 is newer: released 19 Oct 2026, against 19 Feb 2026 for Gemini 3.1 Pro Preview.
- On our own benchmarks, on the results both models have: Gemini 3.1 Pro Preview does better for marketing planning.
Head to head
Every fact side by side
| Gemini 3.1 Pro Preview | Mercury 3 | |
|---|---|---|
| Price per million tokens | $2.00 in · $12.00 out | $0.20 in · $0.70 out |
| Blended (3 in : 1 out) | $4.50 | $0.33 |
| Cheapest host, blended | $4.50 (Google) | – |
| Cost per deck (DeckBench) | $0.14 | $0.012 |
| Cached input, per million | $0.20 cached input | $0.020 cached input |
| Intelligence Index | 29.7 | – |
| Spring Prompt overall | 48 | 39 |
| Output speed, tokens a second | 130 | – |
| Context window | 1,048,576 tokens | 1,000,000 tokens |
| Released | 19 Feb 2026 | 19 Oct 2026 (newer) |
| Weights | Closed | Closed |
| Developer based in | the US | the US |
Prices are the developer's list price where we have read it, otherwise the typical host on OpenRouter; see every model's price. Intelligence and speed from Artificial Analysis.
Which is better for what
Each model's rank among the models on sale today, for each kind of work, from our own benchmarks and licensed sources. Further right is better; the better rank is in green.
Their slides, side by side
The same brief for both: Manchester store investment review for Hearthside Coffee, an invented company. First slide of each deck from DeckBench.
From our research
- Gemini 4 Argon review: Opus-level product data at a quarter of the cost, until you ask it to sell 14 Oct 2026
- BulletBench: we made 23 AI models play speed chess, and the clock was the judge 3 Jul 2026
- Claude vs Gemini vs GPT in a 12-Month Marketing Simulation 25 Mar 2026
- The AI Marketing Benchmark That Punishes Plausible-Sounding Strategy 20 Mar 2026
Every shared result
Each model's best result on every measure both have, grouped by benchmark, with the setting that produced it. Under each measure, every model that benchmark has measured is a grey tick, best to the right, so you can see where the two sit in the field. The headline measures of each benchmark come first; the rest are under "Show all". Green marks the better value; where a source reports ranges that overlap, neither is marked.
| Measure | Gemini 3.1 Pro Preview | Mercury 3 |
|---|---|---|
| BulletBench measured by Spring Prompt · 3 results | ||
| Cost per game · Bullet 60sUS dollars, lower is better 29 · 7 of 32 measured | $0.0446low reasoning | $0.0020no reasoning |
| Ladder Elo · Bullet 60sladder Elo, higher is better 11 · 15 of 32 measured | 529low reasoning | 491no reasoning |
| Games lost on time · Bullet 60s% of games, lower is better 24 · 1 of 32 measured | 58.3%low reasoning | 0.0%no reasoning |
| DeckBench measured by Spring Prompt · 3 results | ||
| Cost per deckUS dollars, lower is better 14 · 4 of 24 measured | $0.14 | $0.0116 |
| Deck ratingrating, higher is betterThe rating weighs each win by how strong the other deck was; the win rate counts wins against whichever decks a model happened to meet, so the two can disagree. 19 · 18 of 24 measured | 788 | 812 |
| Accurate decks% of tasks, higher is better 9 · 20 of 24 measured | 50.0% | 0.0% |
| ROASBench measured by Spring Prompt · 3 results | ||
| Overall scorescore out of 100, higher is better 10 · 18 of 24 measured | 43.5 | 26.1 |
| Audience scorescore out of 100, higher is better 6 · 21 of 24 measured | 67.5 | 43.2 |
| Business scorescore out of 100, higher is better 12 · 18 of 24 measured | 35.9 | 17.6 |
| SurveyBench measured by Spring Prompt · 3 results | ||
| Analysis ratingrating, higher is betterThe rating weighs each win by how strong the other analysis was; the win rate counts wins against whichever analyses a model happened to meet, so the two can disagree. 8 · 9 of 13 measured | 797 | 752 |
| Cost per taskUS dollars, lower is better 10 · 3 of 12 measured | $0.33 | $0.0216 |
| Analysis scorepoints of 100, higher is better 7 · 12 of 13 measured | 66.4 | 42.2 |
Show all 51 results (39 more)
| Measure | Gemini 3.1 Pro Preview | Mercury 3 |
|---|---|---|
| BulletBench measured by Spring Prompt · 2 results | ||
| Invalid moves · Bullet 60s% of moves, lower is better 1 · 1 of 32 measured | 0.0%low reasoning | 0.0%low reasoning |
| Median move time · Bullet 60smilliseconds, lower is better 30 · 3 of 32 measured | 3.1 slow reasoning | 0.4 sno reasoning |
| DeckBench measured by Spring Prompt · 14 results | ||
| Caveat dropped% of tasks, lower is better 12 · 12 of 24 measured | 16.7% | 16.7% |
| Clean layout% of tasks, higher is better 12 · 6 of 24 measured | 50.0% | 66.7% |
| Design quality% of the maximum, higher is better 19 · 16 of 24 measured | 51.4% | 58.5% |
| Draft figure quoted% of tasks, lower is better 1 · 12 of 24 measured | 0.0% | 33.3% |
| Findings missing% of tasks, lower is better 1 · 17 of 24 measured | 0.0% | 16.7% |
| Head-to-head win rate% of comparisons, higher is betterThe rating weighs each win by how strong the other deck was; the win rate counts wins against whichever decks a model happened to meet, so the two can disagree. 19 · 16 of 24 measured | 34.0% | 44.0% |
| Layout defects% of tasks, lower is better 12 · 6 of 24 measured | 50.0% | 33.3% |
| Misleading metric used% of tasks, lower is better 1 · 22 of 24 measured | 0.0% | 16.7% |
| Presentable decks% of tasks, higher is better 10 · 12 of 24 measured | 16.7% | 0.0% |
| Recommendation late or wrong% of tasks, lower is better 17 · 22 of 24 measured | 50.0% | 83.3% |
| Slides needing work% of tasks, lower is better 21 · 7 of 24 measured | 83.3% | 33.3% |
| Time per deckseconds, lower is better 8 · 9 of 24 measured | 78.0 | 83.3 |
| Unsupported claims% of tasks, lower is better 1 · 11 of 24 measured | 0.0% | 16.7% |
| Unsupported numbers% of tasks, lower is better 1 · 20 of 24 measured | 0.0% | 16.7% |
| ROASBench measured by Spring Prompt · 6 results | ||
| Consistency scorescore out of 100, higher is better 6 · 19 of 24 measured | 33.9 | 15.1 |
| Contribution profitsimulated US dollars, higher is better 13 · 18 of 24 measured | $507,736 | $104,868 |
| Cost of a runUS dollars, lower is better 18 · 6 of 24 measured | $0.52 | $0.0533 |
| Months over budgetmonths of 12, lower is better 1 · 1 of 24 measured | 0 | 0 |
| Planning scorescore out of 100, higher is better 8 · 23 of 24 measured | 54.9 | 53.8 |
| Return on ad spendprofit per $1 spent, higher is better 13 · 18 of 24 measured | $0.42 | $0.10 |
| SurveyBench measured by Spring Prompt · 17 results | ||
| Head-to-head win rate% of comparisons, higher is betterThe rating weighs each win by how strong the other analysis was; the win rate counts wins against whichever analyses a model happened to meet, so the two can disagree. 9 · 6 of 13 measured | 34.0% | 48.6% |
| Leading or double-barrelled questions% of tasks, lower is better 6 · 8 of 13 measured | 44.4% | 55.6% |
| Mistaken next steps% of tasks, lower is better 7 · 5 of 13 measured | 33.3% | 22.2% |
| Numbers right% of answers, higher is better 1 · 13 of 13 measured | 100.0% | 63.3% |
| Objectives unanswerable% of tasks, lower is better 1 · 1 of 13 measured | 0.0% | 0.0% |
| Precision ignored% of tasks, lower is better 8 · 1 of 13 measured | 55.6% | 0.0% |
| Research scorepoints of 100, higher is better 7 · 11 of 13 measured | 71.3 | 56.8 |
| Sound research% of tasks, higher is better 6 · 6 of 13 measured | 0.0% | 0.0% |
| Stakeholder's view presumed% of tasks, lower is better 7 · 7 of 13 measured | 22.2% | 22.2% |
| Survey plan scorepoints of 100, higher is better 10 · 6 of 13 measured | 82.9 | 90.8 |
| Survey structure% of tasks, lower is better 7 · 7 of 13 measured | 22.2% | 22.2% |
| Time per taskseconds, lower is better 8 · 10 of 12 measured | 170 | 194 |
| Traps handled% of traps, higher is better 9 · 11 of 13 measured | 71.0% | 60.7% |
| Traps missed% of tasks, lower is better 7 · 7 of 13 measured | 88.9% | 88.9% |
| Unsupported findings% of tasks, lower is better 7 · 4 of 13 measured | 77.8% | 44.4% |
| Wrong numbers% of tasks, lower is better 1 · 9 of 13 measured | 0.0% | 44.4% |
| Wrong recommendation% of tasks, lower is better 8 · 12 of 13 measured | 44.4% | 77.8% |
Compare them with other models
- Gemini 3.1 Pro Preview vs Claude Opus 5.5Most intelligent at $3–10 per million tokens
- Gemini 3.1 Pro Preview vs Inkling SmallFastest with similar intelligence
- Mercury 3 vs Claude Opus 5.5Highest-scoring overall available today
- Mercury 3 vs GPT-6 LunaJust above overall
- Mercury 3 vs GLM-5.3Just below overall
Quick answers
Is Gemini 3.1 Pro Preview better than Mercury 3?
Pick Gemini 3.1 Pro Preview if quality matters most: it scores higher (Spring Prompt overall 48 against 39). Pick Mercury 3 if cost matters more: it costs 12 times less per deck on DeckBench.
Which is cheaper, Gemini 3.1 Pro Preview or Mercury 3?
Mercury 3 is cheaper to run: $0.012 against $0.14 per deck on DeckBench (12 times less).
Which is better for decks from an analysis, Gemini 3.1 Pro Preview or Mercury 3?
Mercury 3 ranks 18 of 24 models on sale for turning a finished analysis into a deck you could present as it is, against 19 for Gemini 3.1 Pro Preview.
Which is better for user surveys, Gemini 3.1 Pro Preview or Mercury 3?
Gemini 3.1 Pro Preview ranks 8 of 13 models on sale for planning a user survey and reading its results without being misled, against 9 for Mercury 3.
Which is better for marketing planning, Gemini 3.1 Pro Preview or Mercury 3?
Gemini 3.1 Pro Preview ranks 10 of 24 models on sale for planning a year of ad spend without overspending, against 18 for Mercury 3.
Which is better for speed under pressure, Gemini 3.1 Pro Preview or Mercury 3?
Gemini 3.1 Pro Preview ranks 5 of 27 models on sale for good decisions against a real clock (fast chess), against 10 for Mercury 3.
Which has the bigger context window, Gemini 3.1 Pro Preview or Mercury 3?
Gemini 3.1 Pro Preview: 1,048,576 tokens, against 1,000,000 for Mercury 3.
Run Gemini 3.1 Pro Preview and Mercury 3 on your own prompt
Benchmarks aren't your data. Try both side by side in the playground, with the cost of every answer.