Gemini 2.5 Pro vs GPT-4o
Complete pricing and performance comparison between Google's Gemini 2.5 Pro and OpenAI's GPT-4o.
Quick Verdict
Cheaper
Gemini 2.5 Pro
2.0x cheaper input, 1.0x cheaper output
Larger Context
Gemini 2.5 Pro
1.0M vs 128K
Higher Quality
Gemini 2.5 Pro
Score: 35 vs 17
Faster
GPT-4o
135 vs 128 tok/s
Pricing Comparison
| Spec | Gemini 2.5 Pro | GPT-4o | Difference |
|---|---|---|---|
| Provider | OpenAI | ||
| Input / 1M tokens | $1.25 | $2.5 | Gemini 2.5 Pro is 50% more expensive |
| Output / 1M tokens | $10 | $10 | Same |
| Context Window | 1.0M | 128K | 8x difference |
| Max Output | 66K | 16K | |
| Tokenizer | cl100k_base | o200k_base |
Performance Benchmarks
| Metric | Gemini 2.5 Pro | GPT-4o | Winner |
|---|---|---|---|
| Quality Index | 35 | 17 | Gemini 2.5 Pro |
| Output Speed | 128 tok/s | 135 tok/s | GPT-4o |
| Time to First Token | 22.13s | 0.53s | GPT-4o |
| Value (Quality/$) | 27.7 | 6.9 | 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 2.5 Pro | GPT-4o | Savings |
|---|---|---|---|
Single request 1K in / 300 out | $0.0042 | $0.0055 | Gemini 2.5 Pro saves $0.0013 |
10 requests 10K in / 3K out | $0.042 | $0.055 | Gemini 2.5 Pro saves $0.013 |
100 requests 100K in / 30K out | $0.425 | $0.550 | Gemini 2.5 Pro saves $0.125 |
1,000 requests 1M in / 300K out | $4.25 | $5.50 | Gemini 2.5 Pro saves $1.25 |
10,000 requests 10M in / 3M out | $42.50 | $55.00 | Gemini 2.5 Pro saves $12.50 |
1M requests/mo 1B in / 300M out | $4250.00 | $5500.00 | Gemini 2.5 Pro saves $1250.00 |
Pros & Cons
Gemini 2.5 Pro Strengths
- +Cheaper input tokens
- +Larger context window (1.0M vs 128K)
- +Higher max output tokens
- +Higher quality score (35 vs 17)
GPT-4o Strengths
- +Faster output (135 vs 128 tok/s)
- +Lower latency (faster first token)
When to Use Each Model
Choose Gemini 2.5 Pro for
- →Long documents, large codebases, or multi-turn conversations
- →Generating long-form content or detailed code
- →Tasks requiring maximum accuracy and reasoning
Choose GPT-4o for
- →Real-time applications, chat, or autocomplete
Frequently Asked Questions
Which is cheaper, Gemini 2.5 Pro or GPT-4o?
For input tokens, Gemini 2.5 Pro is 2.0x cheaper at $1.25/1M tokens. For output tokens, Gemini 2.5 Pro is 1.0x cheaper at $10/1M tokens. At typical usage (1M input + 300K output), Gemini 2.5 Pro costs $4.25 vs GPT-4o at $5.50.
What's the context window difference?
Gemini 2.5 Pro supports 1.0M context (1,048,576 tokens), while GPT-4o supports 128K (128,000 tokens). Gemini 2.5 Pro can handle 8x more context in a single request.
Which model has better benchmarks?
Quality Index: Gemini 2.5 Pro scores 35 vs GPT-4o at 17. Speed: Gemini 2.5 Pro generates 128 tok/s vs GPT-4o at 135 tok/s. Time to first token: Gemini 2.5 Pro at 22.13s vs GPT-4o at 0.53s.
When should I choose Gemini 2.5 Pro over GPT-4o?
Choose Gemini 2.5 Pro when you need: Cheaper input tokens, Larger context window (1.0M vs 128K), Higher max output tokens, Higher quality score (35 vs 17). Choose GPT-4o when you need: Faster output (135 vs 128 tok/s), Lower latency (faster first token).
How much would 10,000 API requests cost?
At 1K input + 300 output tokens per request (typical chat): Gemini 2.5 Pro = $42.50, GPT-4o = $55.00. At 10K input + 1K output per request (longer conversations): Gemini 2.5 Pro = $225.00, GPT-4o = $350.00.