Gemini 3.5 Flash vs GPT-5.5
API pricing, context window and capabilities for Gemini 3.5 Flash and GPT-5.5, side by side. Prices are the cheapest serving route per 1M tokens, verified against LiteLLM and OpenRouter.
Verdict
computed from the published numbersGemini 3.5 Flash wins on price. GPT-5.5 wins on coding, on intelligence and on context window.
Price
Gemini 3.5 Flash
Coding
GPT-5.5
Intelligence
GPT-5.5
Context window
GPT-5.5
Key takeaways
who wins on what, from the published numbersGemini 3.5 Flash wins
- Cheaper input ($1.50 vs $5.00 /1M)
- Cheaper output ($9.00 vs $30.00 /1M)
- More serving providers (3 vs 2)
- Supports audio
GPT-5.5 wins
- Larger context window (1M vs 1.1M)
- Higher max output (66K vs 128K)
Cheaper overall
Gemini 3.5 Flash
$1.50 + $9.00 /1M
Larger context
GPT-5.5
1.1M
More providers
Gemini 3.5 Flash
3 providers
Pricing & specs
cheapest serving route · per 1M tokens| Gemini 3.5 Flash | GPT-5.5 | |
|---|---|---|
| Input $/1M | $1.50 best | $5.00 |
| Output $/1M | $9.00 best | $30.00 |
| Context window | 1M | 1.1M best |
| Max output | 66K | 128K best |
| Serving providers | 3 best | 2 |
| Released | 2026-05-22 | 2026-04-23 |
Benchmarks
Artificial Analysis indices, side by side| Gemini 3.5 Flash | GPT-5.5 | |
|---|---|---|
| Intelligence | 50.2 | 54.8 best |
| Coding | 70.1 | 74.9 best |
| GPQA Diamond | 92% | 94% best |
| Output speed | 188 t/s best | 87 t/s |
| Latency (TTFT) | 18.79s best | 23.21s |
Cost calculator
choose a serving route for each sideInput tokens / month
Output tokens / month
Gemini 3.5 Flash
via Vertex AI
$17
GPT-5.5
via Azure
$55
Capabilities
feature support, side by side| Feature | Gemini 3.5 Flash | GPT-5.5 |
|---|---|---|
| Vision | ✓ | ✓ |
| Tool use | ✓ | ✓ |
| Reasoning | ✓ | ✓ |
| Audio | ✓ | — |
| Prompt caching | ✓ | ✓ |
| Structured output | ✓ | ✓ |
| Web search | ✓ | ✓ |
Related comparisons
Frequently asked questions
Which is cheaper, Gemini 3.5 Flash or GPT-5.5?
Gemini 3.5 Flash is cheaper for input ($1.50 vs $5.00 per 1M tokens). Gemini 3.5 Flash is cheaper for output ($9.00 vs $30.00 per 1M tokens).
What is the context window difference between Gemini 3.5 Flash and GPT-5.5?
Gemini 3.5 Flash has a 1M-token context window and GPT-5.5 has 1.1M tokens, so GPT-5.5 can take a larger prompt.
How do Gemini 3.5 Flash and GPT-5.5 compare on benchmarks?
On the tracked Artificial Analysis indices, GPT-5.5 leads on coding, and GPT-5.5 leads on intelligence.
Pricing verified against LiteLLM + OpenRouter + provider pages · refreshed daily
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