Gemini 2.5 Flash vs GPT-5.4 Nano
Complete pricing and performance comparison between Google's Gemini 2.5 Flash and OpenAI's GPT-5.4 Nano.
Quick Verdict
Cheaper
GPT-5.4 Nano
1.5x cheaper input, 2.0x cheaper output
Larger Context
Gemini 2.5 Flash
1.0M vs 400K
Pricing Comparison
| Spec | Gemini 2.5 Flash | GPT-5.4 Nano | Difference |
|---|---|---|---|
| Provider | OpenAI | ||
| Input / 1M tokens | $0.3 | $0.2 | GPT-5.4 Nano is 33% more expensive |
| Output / 1M tokens | $2.5 | $1.25 | GPT-5.4 Nano is 50% more expensive |
| Context Window | 1.0M | 400K | 3x difference |
| Max Output | 66K | 128K | |
| Tokenizer | cl100k_base | o200k_base |
Performance Benchmarks
| Metric | Gemini 2.5 Flash | GPT-5.4 Nano | Winner |
|---|---|---|---|
| Quality Index | 21 | -- | N/A |
| Output Speed | 231 tok/s | -- | N/A |
| Value (Quality/$) | 68.7 | -- | 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 Flash | GPT-5.4 Nano | Savings |
|---|---|---|---|
Single request 1K in / 300 out | $0.0010 | $0.0006 | Same |
10 requests 10K in / 3K out | $0.010 | $0.0057 | GPT-5.4 Nano saves $0.0047 |
100 requests 100K in / 30K out | $0.105 | $0.058 | GPT-5.4 Nano saves $0.047 |
1,000 requests 1M in / 300K out | $1.05 | $0.575 | GPT-5.4 Nano saves $0.475 |
10,000 requests 10M in / 3M out | $10.50 | $5.75 | GPT-5.4 Nano saves $4.75 |
1M requests/mo 1B in / 300M out | $1050.00 | $575.00 | GPT-5.4 Nano saves $475.00 |
Pros & Cons
Gemini 2.5 Flash Strengths
- +Larger context window (1.0M vs 400K)
GPT-5.4 Nano Strengths
- +Cheaper input tokens
- +Cheaper output tokens
- +Higher max output tokens
When to Use Each Model
Choose Gemini 2.5 Flash for
- →Long documents, large codebases, or multi-turn conversations
Choose GPT-5.4 Nano for
- →Budget-conscious projects where cost is the primary factor
- →Generating long-form content or detailed code
Frequently Asked Questions
Which is cheaper, Gemini 2.5 Flash or GPT-5.4 Nano?
For input tokens, GPT-5.4 Nano is 1.5x cheaper at $0.2/1M tokens. For output tokens, GPT-5.4 Nano is 2.0x cheaper at $1.25/1M tokens. At typical usage (1M input + 300K output), Gemini 2.5 Flash costs $1.05 vs GPT-5.4 Nano at $0.575.
What's the context window difference?
Gemini 2.5 Flash supports 1.0M context (1,048,576 tokens), while GPT-5.4 Nano supports 400K (400,000 tokens). Gemini 2.5 Flash can handle 3x more context in a single request.
Which model has better benchmarks?
When should I choose Gemini 2.5 Flash over GPT-5.4 Nano?
Choose Gemini 2.5 Flash when you need: Larger context window (1.0M vs 400K). Choose GPT-5.4 Nano when you need: Cheaper input tokens, Cheaper output tokens, Higher max output tokens.
How much would 10,000 API requests cost?
At 1K input + 300 output tokens per request (typical chat): Gemini 2.5 Flash = $10.50, GPT-5.4 Nano = $5.75. At 10K input + 1K output per request (longer conversations): Gemini 2.5 Flash = $55.00, GPT-5.4 Nano = $32.50.
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