Claude Sonnet 4 vs o3: API Cost Comparison
Compare the API pricing, context windows, features, and real-world cost projections for Claude Sonnet 4 (Anthropic) and o3 (OpenAI). Use the interactive calculator below to compute your exact monthly cost based on your token usage and request volume.
Prices verified Mar 24, 2026
Interactive Cost Calculator
Fills in typical token counts for a workload type
Tokens in each prompt sent to the model
Tokens generated in each response
Total API calls per month
Showing costs for 2 models. Cheapest: o3 at $60.00/month.
| Alert | |||||||
|---|---|---|---|---|---|---|---|
Besto3 | OpenAI | $60.00 | $0.006000 | $20.00 | $40.00 | 42.9% | Alerts coming soon |
Claude Sonnet 4 | Anthropic | $105.00 | $0.010500 | $30.00 | $75.00 | — | Alerts coming soon |
Monthly Cost Comparison
Price Comparison at a Glance
All prices are in USD per 1 million tokens ($/M tokens). Lower is cheaper.
| Pricing Type | Claude Sonnet 4 | o3 | Cheaper |
|---|---|---|---|
| Input (standard) | $3.00/M | $2.00/M | o3 |
| Output | $15.00/M | $8.00/M | o3 |
| Cached input | $0.30/M | $0.50/M | Claude Sonnet 4 |
| Batch input | $1.50/M | N/A | — |
| Batch output | $7.50/M | N/A | — |
Prices last verified: 2026-03-06 – 2026-03-24
Cost Breakdown by Usage Volume
Estimated monthly costs at different request volumes, assuming 1,000 input tokens and 500 output tokens per request. Adjust in the calculator above for your specific use case.
| Volume | Claude Sonnet 4Monthly | o3Monthly | Claude Sonnet 4Per request | o3Per request |
|---|---|---|---|---|
| 1K requests/mo | $10.50 | $6.00 | $0.010500 | $0.006000 |
| 10K requests/mo | $105.00 | $60.00 | $0.010500 | $0.006000 |
| 100K requests/mo | $1,050.00 | $600.00 | $0.010500 | $0.006000 |
| 1M requests/mo | $10,500.00 | $6,000.00 | $0.010500 | $0.006000 |
Green values indicate the lower-cost option at each volume tier. Cost per request is calculated at 1,000 input + 500 output tokens using standard (non-batch, non-cached) pricing.
Price History
Input price per 1M tokensWhen to Choose Claude Sonnet 4
by Anthropic
- Code generation
- Content & copywriting
- RAG / Semantic search
Input / 1M tokens
$3.00/M
Output / 1M tokens
$15.00/M
Context window
200,000
Tier
mid
When to Choose o3
by OpenAI
- Code generation
- Document summarization
Input / 1M tokens
$2.00/M
Output / 1M tokens
$8.00/M
Context window
200,000
Tier
reasoning
Key Differences Beyond Price
Cost is only one factor in choosing an AI model. Context window size, rate limits, supported features, and latency all affect whether a model fits your use case.
| Capability | Claude Sonnet 4 | o3 |
|---|---|---|
| Context window | 200,000 tokens | 200,000 tokens |
| Max output tokens | 64,000 tokens | 100,000 tokens |
| Performance tier | Mid | Reasoning |
| Vision / image input | Yes | Yes |
| Function calling | Yes | Yes |
| JSON mode | Yes | Yes |
| Prompt caching | Yes | Yes |
| Batch API (50% discount) | Yes | No |
| Extended reasoning | Yes | Yes |
| Fine-tuning | No | No |
| Rate limit (req/min) | 4,000 | 1,000 |
Claude Sonnet 4 notes
Extended thinking mode available for complex reasoning tasks. Strong coding benchmark scores.
o3 notes
State-of-the-art reasoning performance. Costs reflect internal thinking tokens. Price reduced significantly from launch.
Frequently Asked Questions
Is Claude Sonnet 4 cheaper than o3?
At standard usage (1,000 input tokens, 500 output tokens, 100,000 requests/month), o3 costs $600.00/month versus $1,050.00/month for Claude Sonnet 4 — a 43% saving. Your actual savings will vary based on your token profile; output-heavy workloads amplify differences in output pricing.
Which model has a larger context window, Claude Sonnet 4 or o3?
Both Claude Sonnet 4 and o3 have the same context window: 200,000 tokens.
Do Claude Sonnet 4 and o3 support the Batch API?
Claude Sonnet 4 supports the Batch API (50% discount for async processing), while o3 does not. If your workload tolerates up to 24-hour latency, routing to Claude Sonnet 4 with batch pricing could significantly cut costs versus o3's standard rate.
Which model offers better prompt caching?
Both Claude Sonnet 4 and o3 support prompt caching. Claude Sonnet 4 caches repeated input at $0.30/M (vs $3.00/M standard), while o3 caches at $0.50/M (vs $2.00/M standard). For workloads with large, repeated system prompts or document context, caching can reduce effective input costs by 60–90%.
What are the best use cases for Claude Sonnet 4 vs o3?
Both models are well-suited for Code generation. Claude Sonnet 4 is particularly strong for Content & copywriting, RAG / Semantic search. o3 is favored for Document summarization. At the same quality level, the lower-cost model is usually preferable; use this page's calculator to compare total monthly spend at your volume.
What is the cost per request for Claude Sonnet 4 vs o3?
At 1,000 input tokens and 500 output tokens per request — a typical conversational workload — Claude Sonnet 4 costs $0.010500 per request and o3 costs $0.006000 per request. At 100,000 requests/month, that translates to $1,050.00 and $600.00 respectively. Use the interactive calculator to adjust these parameters for your actual workload.
Claude Sonnet 4 vs o3: Summary
When comparing Claude Sonnet 4 and o3 for API cost, the right choice depends on your workload's token profile, required features, and tolerance for latency. o3 offers lower total cost at standard usage volumes (1,000 input + 500 output tokens per request at 100,000 requests/month) at $600.00/month, compared to $1,050.00/month for Claude Sonnet 4.
Both models are priced in USD per million tokens, the standard unit across all major AI API providers. Claude Sonnet 4 charges $3.00/M for input tokens and $15.00/M for output tokens. o3 charges $2.00/M input and $8.00/M output. If your workload is output-heavy (more tokens generated than consumed as input), the model with the lower output price compounds cost savings significantly at scale.
Prompt caching is supported by both models. For workloads with large, repeated system prompts or document context — such as RAG pipelines or multi-turn conversations with a fixed knowledge base — prompt caching can reduce effective input costs by 60–90%, which may change the cost ranking between these two models at your specific usage pattern.
Context window capacity differs between the two: Both models support 200,000 tokens per request. A larger context window is essential for document summarization, large codebase analysis, and multi-document retrieval-augmented generation (RAG) applications.
Use the interactive calculator at the top of this page to enter your actual token usage and monthly request volume for a precise cost comparison tailored to your workload. Adjust for batch API discounts and prompt caching to find the most cost-effective option for your specific deployment.
Related Comparisons
Explore other model comparisons from the same providers or performance tiers.
Related Provider Pages
View complete pricing tables and model lineups for the providers behind these models.
Relevant Use Cases
See cost recommendations for workloads where Claude Sonnet 4 or o3 is recommended.