AI model comparison
Claude Sonnet 4.5 vs Gemini 2.5 Pro
Pricing, context window, benchmarks, and features compared side by side. Or skip the guesswork and send one prompt to both.
Anthropic
Claude Sonnet 4.5
Claude Sonnet 4.5 is Anthropic’s most advanced Sonnet model to date, optimized for real-world agents and coding workflows.
- Input / 1M
- $3
- Output / 1M
- $15
- Context
- 1M
Gemini 2.5 Pro
Gemini 2.5 Pro is Google’s state-of-the-art AI model designed for advanced reasoning, coding, mathematics, and scientific tasks.
Gemini 2.5 Pro is scheduled to be retired on October 20, 2026. Consider Gemini 3.1 Pro Preview instead.
- Input / 1M
- $1.25
- Output / 1M
- $10
- Context
- 1.05M
At a glance
Quick verdict
How the two models stack up on the things people ask about most.
Lower price
Gemini 2.5 Pro
1.8x cheaper for a typical chat
Higher intelligence score
Claude Sonnet 4.5
20.7 vs 16.1 on Artificial Analysis
Larger context window
Gemini 2.5 Pro
1.05M vs 1M tokens
Newer release
Claude Sonnet 4.5
Released September 29, 2025
Benchmarks
Benchmark scores
Independent scores from Artificial Analysis. Higher is better.
Intelligence index
Claude Sonnet 4.520.7Gemini 2.5 Pro16.1Coding index
Claude Sonnet 4.552.1Gemini 2.5 Pro33.3Agentic index
Claude Sonnet 4.515.8Gemini 2.5 Pro1.6Pricing
Claude Sonnet 4.5 vs Gemini 2.5 Pro API pricing
Per-token API rates. Cheaper option highlighted.
| Metric | Claude Sonnet 4.5 | Gemini 2.5 Pro |
|---|---|---|
| Input tokensPer 1M tokens | $3 | $1.25 |
| Output tokensPer 1M tokens | $15 | $10 |
| Cached input (read)Per 1M tokens | $0.30 | $0.13 |
| Cache writePer 1M tokens | $3.75 | $0.38 |
| Long-context pricingPer 1M tokens, for very long prompts | $6 in / $22.50 out above 200K | $2.50 in / $15 out above 200K |
| Web searchPer request | $0.01 | $0.014 |
What it costs in practice
Estimated cost per 1,000 requests at standard rates. Coding and long-document figures also show the cost when the input is already cached.
Chat message
2K in, 500 out
Claude Sonnet 4.5$13.50Gemini 2.5 Pro$7.50Coding task
30K in, 4K out
Claude Sonnet 4.5$150$69 cachedGemini 2.5 Pro$77.50$43.75 cachedLong document summary
150K in, 2K out
Claude Sonnet 4.5$480$75 cachedGemini 2.5 Pro$207.50$38.75 cachedSpecs
Context window and capabilities
How much each model can read, how much it can write, and what it accepts as input.
| Metric | Claude Sonnet 4.5 | Gemini 2.5 Pro |
|---|---|---|
| Context window | 1M tokens | 1.05M tokens |
| Max output | 64K tokens | 66K tokens |
| Input types | File, Image, Text | Audio, File, Image, Text, Video |
| Output types | Text | Text |
| Reasoning effort levels | Not available | Not available |
| Default reasoning effort | Not available | Not available |
| Release date | September 29, 2025 | June 17, 2025 |
Features
Supported features
API features available for each model.
| Metric | Claude Sonnet 4.5 | Gemini 2.5 Pro |
|---|---|---|
| Tool calling | Supported | Supported |
| Structured outputs | Supported | Supported |
| JSON mode | Supported | Supported |
| Reasoning | Supported | Supported |
| Temperature | Supported | Supported |
| Stop sequences | Supported | Supported |
| Deterministic seed | Not supported | Supported |
| Verbosity control | Not supported | Not supported |
Keep exploring
More on these models
Other head-to-heads, the full model page, and the alternatives list for each model.
Claude Sonnet 4.5View full model details- Claude Sonnet 4.5 vs Claude Sonnet 4.6
- Claude Sonnet 4.5 vs Claude Haiku 4.5
- Claude Sonnet 4.5 vs Claude Opus 4.5
- Claude Sonnet 4.5 vs GPT-5.1
- Claude Sonnet 4.5 vs GPT-5.1-Codex
- Claude Sonnet 4.5 vs GPT-5
- Claude Sonnet 4.5 vs Claude Opus 4.1
- Claude Sonnet 4.5 vs o3 Pro
- Claude Sonnet 4.5 vs Qwen3.5 397B A17B
- Claude Sonnet 4.5 vs o3
- Claude Sonnet 4.5 vs Claude Sonnet 4
- Claude Sonnet 4.5 vs o1
Gemini 2.5 ProView full model details- Gemini 2.5 Pro vs Gemini 3.1 Flash Lite
- Gemini 2.5 Pro vs Gemini 2.5 Flash
- Gemini 2.5 Pro vs Claude Haiku 4.5
- Gemini 2.5 Pro vs GPT-4.1
- Gemini 2.5 Pro vs Claude Sonnet 4
- Gemini 2.5 Pro vs o4 Mini
- Gemini 2.5 Pro vs Kimi K2 0905
- Gemini 2.5 Pro vs o1
- Gemini 2.5 Pro vs Mistral Medium 3.5
- Gemini 2.5 Pro vs Command A
- Gemini 2.5 Pro vs Sonar Reasoning Pro
Our take
Gemini 2.5 Pro is 1.8x cheaper for a typical chat. Claude Sonnet 4.5 scores higher on the Artificial Analysis Intelligence Index (20.7 vs 16.1). Gemini 2.5 Pro has the larger context window (1.05M vs 1M tokens). The right pick depends on your workload, so the quickest way to settle it is to send the same prompt to both and compare.
FAQ
Frequently asked questions
Is Claude Sonnet 4.5 or Gemini 2.5 Pro cheaper?
Gemini 2.5 Pro is cheaper for a typical chat (2K input tokens and 500 output tokens). Gemini 2.5 Pro costs $1.25 per 1M input tokens and $10 per 1M output tokens, while Claude Sonnet 4.5 costs $3 per 1M input tokens and $15 per 1M output tokens.
Which has a bigger context window, Claude Sonnet 4.5 or Gemini 2.5 Pro?
Gemini 2.5 Pro supports up to 1.05M tokens of context, compared with 1M for Claude Sonnet 4.5.
Is Claude Sonnet 4.5 smarter than Gemini 2.5 Pro?
On the Artificial Analysis Intelligence Index, Claude Sonnet 4.5 scores 20.7 and Gemini 2.5 Pro scores 16.1, putting Claude Sonnet 4.5 ahead. Benchmarks don't capture everything, so the best test is running your own prompts through both.
Can I use Claude Sonnet 4.5 and Gemini 2.5 Pro at the same time?
Yes. Shortcut Chat sends one prompt to multiple models at once, so you can see Claude Sonnet 4.5 and Gemini 2.5 Pro answer side by side and keep the better response.
Why choose? Ask both.
Send one prompt to Claude Sonnet 4.5 and Gemini 2.5 Pro at the same time. Compare the answers side by side and keep the best one.