AI model comparison
o3 Pro vs Claude Sonnet 4
Pricing, context window, benchmarks, and features compared side by side. Or skip the guesswork and send one prompt to both.
OpenAI
o3 Pro
The o-series of models are trained with reinforcement learning to think before they answer and perform complex reasoning.
- Input / 1M
- $20
- Output / 1M
- $80
- Context
- 200K
Anthropic
Claude Sonnet 4
Claude Sonnet 4 significantly enhances the capabilities of its predecessor, Sonnet 3.7, excelling in both coding and reasoning tasks with improved precision and controllability.
- Input / 1M
- $3
- Output / 1M
- $15
- Context
- 200K
At a glance
Quick verdict
How the two models stack up on the things people ask about most.
Lower price
Claude Sonnet 4
5.9x cheaper for a typical chat
Higher intelligence score
o3 Pro
21.9 vs 18.9 on Artificial Analysis
Larger context window
Tie
200K vs 200K tokens
Newer release
o3 Pro
Released June 10, 2025
Benchmarks
Benchmark scores
Independent scores from Artificial Analysis. Higher is better.
Intelligence index
o3 Pro21.9Claude Sonnet 418.9Coding index
o3 ProNot availableClaude Sonnet 437.6Agentic index
o3 ProNot availableClaude Sonnet 4Not availablePricing
o3 Pro vs Claude Sonnet 4 API pricing
Per-token API rates. Cheaper option highlighted.
| Metric | o3 Pro | Claude Sonnet 4 |
|---|---|---|
| Input tokensPer 1M tokens | $20 | $3 |
| Output tokensPer 1M tokens | $80 | $15 |
| Cached input (read)Per 1M tokens | Not available | $0.30 |
| Cache writePer 1M tokens | Not available | $3.75 |
| Long-context pricingPer 1M tokens, for very long prompts | Same rate at any length | $6 in / $22.50 out above 200K |
| Web searchPer request | $0.01 | $0.01 |
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
o3 Pro$80Claude Sonnet 4$13.50Coding task
30K in, 4K out
o3 Pro$920Claude Sonnet 4$150$69 cachedLong document summary
150K in, 2K out
o3 Pro$3160Claude Sonnet 4$480$75 cachedSpecs
Context window and capabilities
How much each model can read, how much it can write, and what it accepts as input.
| Metric | o3 Pro | Claude Sonnet 4 |
|---|---|---|
| Context window | 200K tokens | 200K tokens |
| Max output | 100K tokens | 64K tokens |
| Input types | File, Image, Text | File, Image, Text |
| Output types | Text | Text |
| Reasoning effort levels | Not available | Not available |
| Default reasoning effort | Not available | Not available |
| Release date | June 10, 2025 | May 22, 2025 |
Features
Supported features
API features available for each model.
| Metric | o3 Pro | Claude Sonnet 4 |
|---|---|---|
| Tool calling | Supported | Supported |
| Structured outputs | Supported | Not supported |
| JSON mode | Supported | Not supported |
| Reasoning | Supported | Supported |
| Temperature | Not supported | Supported |
| Stop sequences | Not supported | Supported |
| Deterministic seed | Supported | Not 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 4View full model details- Claude Sonnet 4 vs Claude Sonnet 4.6
- Claude Sonnet 4 vs GPT-5.1
- Claude Sonnet 4 vs GPT-5.1-Codex
- Claude Sonnet 4 vs GPT-5
- Claude Sonnet 4 vs Claude Opus 4.1
- Claude Sonnet 4 vs Qwen3.5 397B A17B
- Claude Sonnet 4 vs Claude Sonnet 4.5
- Claude Sonnet 4 vs o3
- Claude Sonnet 4 vs Claude Haiku 4.5
- Claude Sonnet 4 vs o4 Mini
- Claude Sonnet 4 vs Gemini 2.5 Pro
- Claude Sonnet 4 vs o1
Our take
Claude Sonnet 4 is 5.9x cheaper for a typical chat. o3 Pro scores higher on the Artificial Analysis Intelligence Index (21.9 vs 18.9). 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 o3 Pro or Claude Sonnet 4 cheaper?
Claude Sonnet 4 is cheaper for a typical chat (2K input tokens and 500 output tokens). Claude Sonnet 4 costs $3 per 1M input tokens and $15 per 1M output tokens, while o3 Pro costs $20 per 1M input tokens and $80 per 1M output tokens.
Which has a bigger context window, o3 Pro or Claude Sonnet 4?
o3 Pro supports up to 200K tokens of context, compared with 200K for Claude Sonnet 4.
Is o3 Pro smarter than Claude Sonnet 4?
On the Artificial Analysis Intelligence Index, o3 Pro scores 21.9 and Claude Sonnet 4 scores 18.9, putting o3 Pro ahead. Benchmarks don't capture everything, so the best test is running your own prompts through both.
Can I use o3 Pro and Claude Sonnet 4 at the same time?
Yes. Shortcut Chat sends one prompt to multiple models at once, so you can see o3 Pro and Claude Sonnet 4 answer side by side and keep the better response.
Why choose? Ask both.
Send one prompt to o3 Pro and Claude Sonnet 4 at the same time. Compare the answers side by side and keep the best one.