AI model comparison
Claude Sonnet 4 vs o3
Pricing, context window, benchmarks, and features compared side by side. Or skip the guesswork and send one prompt to both.
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
OpenAI
o3
o3 is a well-rounded and powerful model across domains. It sets a new standard for math, science, coding, and visual reasoning tasks.
- Input / 1M
- $2
- Output / 1M
- $8
- Context
- 200K
At a glance
Quick verdict
How the two models stack up on the things people ask about most.
Lower price
o3
1.7x cheaper for a typical chat
Higher intelligence score
o3
20.2 vs 18.9 on Artificial Analysis
Larger context window
Tie
200K vs 200K tokens
Newer release
Claude Sonnet 4
Released May 22, 2025
Benchmarks
Benchmark scores
Independent scores from Artificial Analysis. Higher is better.
Intelligence index
Claude Sonnet 418.9o320.2Coding index
Claude Sonnet 437.6o3Not availableAgentic index
Claude Sonnet 4Not availableo3Not availablePricing
Claude Sonnet 4 vs o3 API pricing
Per-token API rates. Cheaper option highlighted.
| Metric | Claude Sonnet 4 | o3 |
|---|---|---|
| Input tokensPer 1M tokens | $3 | $2 |
| Output tokensPer 1M tokens | $15 | $8 |
| Cached input (read)Per 1M tokens | $0.30 | $0.50 |
| Cache writePer 1M tokens | $3.75 | Not available |
| Long-context pricingPer 1M tokens, for very long prompts | $6 in / $22.50 out above 200K | Same rate at any length |
| 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
Claude Sonnet 4$13.50o3$8Coding task
30K in, 4K out
Claude Sonnet 4$150$69 cachedo3$92$47 cachedLong document summary
150K in, 2K out
Claude Sonnet 4$480$75 cachedo3$316$91 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 | o3 |
|---|---|---|
| Context window | 200K tokens | 200K tokens |
| Max output | 64K tokens | 100K 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 | May 22, 2025 | April 16, 2025 |
Features
Supported features
API features available for each model.
| Metric | Claude Sonnet 4 | o3 |
|---|---|---|
| Tool calling | Supported | Supported |
| Structured outputs | Not supported | Supported |
| JSON mode | Not supported | Supported |
| Reasoning | Supported | Supported |
| Temperature | Supported | Not supported |
| Stop sequences | Supported | Not 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 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 o3 Pro
- Claude Sonnet 4 vs Qwen3.5 397B A17B
- Claude Sonnet 4 vs Claude Sonnet 4.5
- 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
o3 is 1.7x cheaper for a typical chat. o3 scores higher on the Artificial Analysis Intelligence Index (20.2 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 Claude Sonnet 4 or o3 cheaper?
o3 is cheaper for a typical chat (2K input tokens and 500 output tokens). o3 costs $2 per 1M input tokens and $8 per 1M output tokens, while Claude Sonnet 4 costs $3 per 1M input tokens and $15 per 1M output tokens.
Which has a bigger context window, Claude Sonnet 4 or o3?
Claude Sonnet 4 supports up to 200K tokens of context, compared with 200K for o3.
Is Claude Sonnet 4 smarter than o3?
On the Artificial Analysis Intelligence Index, Claude Sonnet 4 scores 18.9 and o3 scores 20.2, putting o3 ahead. Benchmarks don't capture everything, so the best test is running your own prompts through both.
Can I use Claude Sonnet 4 and o3 at the same time?
Yes. Shortcut Chat sends one prompt to multiple models at once, so you can see Claude Sonnet 4 and o3 answer side by side and keep the better response.
Why choose? Ask both.
Send one prompt to Claude Sonnet 4 and o3 at the same time. Compare the answers side by side and keep the best one.