Google · 3 models · 24 prompts · 72 runs · benched 2026-09-16
Gemini 3.1 Pro Preview vs Gemini 3.8 Flash vs Gemini 3.5 Flash Lite on 24 tasks: cost, checks, judge score
Same prompts, same temperature, same judge. Gemini 3.8 Flash leads on judge score; the cheapest row costs $0.34 per 1,000 runs. Move the sliders to rank by what you care about.
Leaderboard
Every cell is one OpenRouter call at temperature 0 with the prompt's token cap and reasoning effort "low" where the model supports it. Cost is usage × the catalogue rate in models.json. Quality is one judge call to anthropic/claude-haiku-4.5 against the prompt's rubric, cached per prompt version. Last bench 2026-09-16.
| # | Model | Composite | Judge | Checks | Latency | Words | Cost / run | Per 1,000 runs | $/1M in · out |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Gemini 3.5 Flash Litegoogle/gemini-3.5-flash-lite | 84.6 | 8.29 | 91% | 668ms | 16 | $0.00034 | $0.34 | $0.30 · $2.50 |
| 2 | Gemini 3.8 Flashgoogle/gemini-3.8-flash | 76.9 | 8.79 | 97% | 2.0s | 18 | $0.00044 | $0.44 | $0.75 · $3.75 |
| 3 | Gemini 3.1 Pro Previewgoogle/gemini-3.1-pro-preview | 47.1 | 6.67 | 71% | 2.5s | 10 | $0.00409 | $4.09 | $2.00 · $12.00 |
Per prompt
Open a prompt to read every model's output side by side, with the checks, the judge's reason and reader votes.
Summarise
Summarise a support thread in 60 words
- Top judge score
- Gemini 3.8 Flash · 9/10
- Cheapest scoring ≥ 8
- Gemini 3.8 Flash · $0.40/1k
Summarise
Meeting notes to exactly three bullets
- Top judge score
- Gemini 3.8 Flash · 9/10
- Cheapest scoring ≥ 8
- Gemini 3.8 Flash · $0.34/1k
Summarise
One-sentence changelog summary
- Top judge score
- Gemini 3.5 Flash Lite · 9/10
- Cheapest scoring ≥ 8
- Gemini 3.5 Flash Lite · $0.15/1k
Extract JSON
Invoice text to JSON
- Top judge score
- Gemini 3.5 Flash Lite · 10/10
- Cheapest scoring ≥ 8
- Gemini 3.5 Flash Lite · $0.23/1k
Extract JSON
People mentioned to a JSON array
- Top judge score
- Gemini 3.5 Flash Lite · 9/10
- Cheapest scoring ≥ 8
- Gemini 3.5 Flash Lite · $0.33/1k
Extract JSON
Event announcement to structured JSON
- Top judge score
- Gemini 3.8 Flash · 10/10
- Cheapest scoring ≥ 8
- Gemini 3.8 Flash · $0.31/1k
Classify
Label six support tickets
- Top judge score
- Gemini 3.5 Flash Lite · 10/10
- Cheapest scoring ≥ 8
- Gemini 3.5 Flash Lite · $0.21/1k
Classify
Sentiment of five reviews
- Top judge score
- Gemini 3.5 Flash Lite · 10/10
- Cheapest scoring ≥ 8
- Gemini 3.5 Flash Lite · $0.08/1k
Classify
Single message intent
- Top judge score
- Gemini 3.5 Flash Lite · 10/10
- Cheapest scoring ≥ 8
- Gemini 3.5 Flash Lite · $0.03/1k
Rewrite
Rewrite a stiff notice in a friendly tone
- Top judge score
- Gemini 3.5 Flash Lite · 10/10
- Cheapest scoring ≥ 8
- Gemini 3.5 Flash Lite · $0.22/1k
Rewrite
Jargon to plain English for a 12-year-old
- Top judge score
- Gemini 3.5 Flash Lite · 2/10
- Cheapest scoring ≥ 8
- none
Rewrite
Product update to a 280-character post
- Top judge score
- Gemini 3.8 Flash · 3/10
- Cheapest scoring ≥ 8
- none
Code fix
Fix an off-by-one in Python
- Top judge score
- Gemini 3.5 Flash Lite · 10/10
- Cheapest scoring ≥ 8
- Gemini 3.5 Flash Lite · $0.12/1k
Code fix
Fix a missing await in JavaScript
- Top judge score
- Gemini 3.5 Flash Lite · 10/10
- Cheapest scoring ≥ 8
- Gemini 3.5 Flash Lite · $0.11/1k
Code fix
Parameterise a SQL query in Python
- Top judge score
- Gemini 3.5 Flash Lite · 10/10
- Cheapest scoring ≥ 8
- Gemini 3.5 Flash Lite · $0.14/1k
SQL
Top five customers by 2025 spend
- Top judge score
- Gemini 3.5 Flash Lite · 10/10
- Cheapest scoring ≥ 8
- Gemini 3.5 Flash Lite · $0.20/1k
SQL
Monthly active users
- Top judge score
- Gemini 3.5 Flash Lite · 10/10
- Cheapest scoring ≥ 8
- Gemini 3.5 Flash Lite · $0.24/1k
SQL
Products over 100 units with HAVING
- Top judge score
- Gemini 3.5 Flash Lite · 10/10
- Cheapest scoring ≥ 8
- Gemini 3.5 Flash Lite · $0.14/1k
Reasoning
When does the faster train catch up?
- Top judge score
- Gemini 3.5 Flash Lite · 10/10
- Cheapest scoring ≥ 8
- Gemini 3.5 Flash Lite · $0.52/1k
Reasoning
Count sellable units
- Top judge score
- Gemini 3.5 Flash Lite · 10/10
- Cheapest scoring ≥ 8
- Gemini 3.5 Flash Lite · $0.47/1k
Reasoning
Stacked discounts and tax
- Top judge score
- Gemini 3.5 Flash Lite · 10/10
- Cheapest scoring ≥ 8
- Gemini 3.5 Flash Lite · $0.30/1k
Tool call
Emit a weather tool call
- Top judge score
- Gemini 3.5 Flash Lite · 10/10
- Cheapest scoring ≥ 8
- Gemini 3.5 Flash Lite · $0.09/1k
Tool call
Emit a calendar tool call
- Top judge score
- Gemini 3.5 Flash Lite · 10/10
- Cheapest scoring ≥ 8
- Gemini 3.5 Flash Lite · $0.22/1k
Tool call
Pick the right tool of three
- Top judge score
- Gemini 3.5 Flash Lite · 10/10
- Cheapest scoring ≥ 8
- Gemini 3.5 Flash Lite · $0.11/1k
Frequently asked
Which Google model is cheapest per run on these tasks?
Gemini 3.5 Flash Lite at $0.34 per 1,000 runs, measured from real token usage, not list price.
How is the composite score calculated?
Each model gets a 0-1 score on cost, quality (mean judge score), speed, checks passed and brevity, relative to the other models in the family. Your slider weights combine them into a 0-100 composite. Cost, speed and brevity are log-scaled because prices span decades.
Are these the official prices?
They are the catalogue rates in models.json, synced hourly from OpenRouter's pricing API, multiplied by the tokens each run actually used. The $/1M columns show the rate; the cost columns show what the run cost.