API cost decision in 10 seconds
GPT-5.3-Codex vs 🔥Claude Sonnet 4.6
Pick GPT-5.3-Codex for lower cost; pick Claude Sonnet 4.6 only if the larger context window matters more.
Pricing data updated:
Prices normalized to USD per 1M tokens
Sample workload: 1M input + 500K output
Budget verdict
Pick GPT-5.3-Codex for lower cost; pick Claude Sonnet 4.6 only if the larger context window matters more.
On the standard 1M input plus 500K output workload, GPT-5.3-Codex is estimated at $8.75 vs $10.5 for Claude Sonnet 4.6, saving $1.75 (16.7% lower).
Cost-first pickGPT-5.3-Codex
Context-first pickClaude Sonnet 4.6
Sample savings$1.7516.7%
10x traffic gap$17.5
Claude Sonnet 4.6 has more context, but GPT-5.3-Codex saves $1.75 on the standard workload. At 10x that traffic, the same price gap is about $17.5. Use the calculator below to replace the sample workload with your own token volume.
Cost sensitivity
Workload Sensitivity
GPT-5.3-Codex stays cheaper across input-heavy, balanced, and output-heavy sample workloads.
| Workload shape | Token mix | Better pick | GPT-5.3-Codex | Claude Sonnet 4.6 |
|---|---|---|---|---|
| Input-heavy / RAG | 5M input + 500K output | GPT-5.3-Codex | $15.75 | $22.5 |
| Balanced workload | 1M input + 1M output | GPT-5.3-Codex | $15.75 | $18 |
| Output-heavy chatbot | 1M input + 5M output | GPT-5.3-Codex | $71.75 | $78 |
Estimate your workload cost
Your Workload Cost
This estimate uses normalized public API pricing per 1M tokens. It is a planning aid, not a billing quote. Verify provider pricing, limits, and terms before production use.
Quick Decision
GPT-5.3-Codex has the lower input price, GPT-5.3-Codex has the lower output price, and Claude Sonnet 4.6 offers the larger context window.
For a 1M input token plus 500K output token workload, the estimated API cost is $8.75 for GPT-5.3-Codex and $10.5 for Claude Sonnet 4.6.
Choose GPT-5.3-Codex when you care most about lower input-token price, and lower output-token price.
Choose Claude Sonnet 4.6 when you care most about larger context window.
| Feature | GPT-5.3-Codex (OpenAI) | 🔥Claude Sonnet 4.6 (Anthropic) |
|---|---|---|
| Input Price prompt tokens per 1M | $1.75 | $3 |
| Completion Price per 1M tokens | $14 | $15 |
| Sample Workload Cost 1M input + 500K output | $8.75 | $10.5 |
| Context Window | 400K | 1M |
| Release Date | 2026-02-24 | 2026-02-17 |
| Popularity | #4 |
GPT-5.3-Codex is OpenAI’s most advanced agentic coding model, combining the frontier software engineering performance of GPT-5.2-Codex with the broader reasoning and professional knowledge capabilities of GPT-5.2. It achieves state-of-the-art results...
Sonnet 4.6 is Anthropic's most capable Sonnet-class model yet, with frontier performance across coding, agents, and professional work. It excels at iterative development, complex codebase navigation, end-to-end project management with...
Use-Case Decision Matrix
| Use case | Better pick | Why |
|---|---|---|
| Budget-constrained production | GPT-5.3-Codex | On the standard 1M input plus 500K output workload, GPT-5.3-Codex is estimated at $8.75 vs $10.5 for Claude Sonnet 4.6, saving $1.75 (16.7% lower). |
| High-volume input processing | GPT-5.3-Codex | Lower prompt-token price matters most when prompts or retrieved passages dominate the bill. |
| Long responses and chatbots | GPT-5.3-Codex | Lower output-token price matters most when assistants generate many completion tokens. |
| RAG or long-document work | Claude Sonnet 4.6 | A larger context window leaves more room for retrieved passages and source files. |