Gemini 3.1 Pro vs o3
Complete pricing and performance comparison between Google's Gemini 3.1 Pro and OpenAI's o3.
Quick Verdict
Cheaper
Gemini 3.1 Pro (input) / o3 (output)
Input: 1.0x diff, Output: 1.5x diff
Larger Context
Gemini 3.1 Pro
1.0M vs 200K
Higher Quality
Gemini 3.1 Pro
Score: 57 vs 38
Faster
Gemini 3.1 Pro
120 vs 74 tok/s
Pricing Comparison
| Spec | Gemini 3.1 Pro | o3 | Difference |
|---|---|---|---|
| Provider | OpenAI | ||
| Input / 1M tokens | $2 | $2 | Same |
| Output / 1M tokens | $12 | $8 | o3 is 33% more expensive |
| Context Window | 1.0M | 200K | 5x difference |
| Max Output | 66K | 100K | |
| Tokenizer | cl100k_base | o200k_base |
Performance Benchmarks
| Metric | Gemini 3.1 Pro | o3 | Winner |
|---|---|---|---|
| Quality Index | 57 | 38 | Gemini 3.1 Pro |
| Output Speed | 120 tok/s | 74 tok/s | Gemini 3.1 Pro |
| Time to First Token | 21.32s | 7.97s | o3 |
| Value (Quality/$) | 28.6 | 19.2 | Higher = better value |
Benchmark data from Artificial Analysis. Quality Index is a composite score across reasoning, coding, and knowledge tasks.
Cost at Scale
Estimated cost at different usage levels (3:1 input-to-output token ratio, typical for chat).
| Usage | Gemini 3.1 Pro | o3 | Savings |
|---|---|---|---|
Single request 1K in / 300 out | $0.0056 | $0.0044 | o3 saves $0.0012 |
10 requests 10K in / 3K out | $0.056 | $0.044 | o3 saves $0.012 |
100 requests 100K in / 30K out | $0.560 | $0.440 | o3 saves $0.120 |
1,000 requests 1M in / 300K out | $5.60 | $4.40 | o3 saves $1.20 |
10,000 requests 10M in / 3M out | $56.00 | $44.00 | o3 saves $12.00 |
1M requests/mo 1B in / 300M out | $5600.00 | $4400.00 | o3 saves $1200.00 |
Pros & Cons
Gemini 3.1 Pro Strengths
- +Larger context window (1.0M vs 200K)
- +Faster output (120 vs 74 tok/s)
- +Higher quality score (57 vs 38)
o3 Strengths
- +Cheaper output tokens
- +Higher max output tokens
- +Lower latency (faster first token)
When to Use Each Model
Choose Gemini 3.1 Pro for
- →Long documents, large codebases, or multi-turn conversations
- →Tasks requiring maximum accuracy and reasoning
- →Real-time applications, chat, or autocomplete
Choose o3 for
- →Generating long-form content or detailed code
Frequently Asked Questions
Which is cheaper, Gemini 3.1 Pro or o3?
For input tokens, Gemini 3.1 Pro is 1.0x cheaper at $2/1M tokens. For output tokens, o3 is 1.5x cheaper at $8/1M tokens. At typical usage (1M input + 300K output), Gemini 3.1 Pro costs $5.60 vs o3 at $4.40.
What's the context window difference?
Gemini 3.1 Pro supports 1.0M context (1,048,576 tokens), while o3 supports 200K (200,000 tokens). Gemini 3.1 Pro can handle 5x more context in a single request.
Which model has better benchmarks?
Quality Index: Gemini 3.1 Pro scores 57 vs o3 at 38. Speed: Gemini 3.1 Pro generates 120 tok/s vs o3 at 74 tok/s. Time to first token: Gemini 3.1 Pro at 21.32s vs o3 at 7.97s.
When should I choose Gemini 3.1 Pro over o3?
Choose Gemini 3.1 Pro when you need: Larger context window (1.0M vs 200K), Faster output (120 vs 74 tok/s), Higher quality score (57 vs 38). Choose o3 when you need: Cheaper output tokens, Higher max output tokens, Lower latency (faster first token).
How much would 10,000 API requests cost?
At 1K input + 300 output tokens per request (typical chat): Gemini 3.1 Pro = $56.00, o3 = $44.00. At 10K input + 1K output per request (longer conversations): Gemini 3.1 Pro = $320.00, o3 = $280.00.