Anthropic Claude Sonnet 5 (1M) vs OpenAI GPT-5.6 (1M)
Side-by-side comparison of pricing, context window, capabilities, and a real-cost sample workload.
Option A
Anthropic Claude Sonnet 5 (1M)
by Anthropic
Context:1M
Input:$3.00 / 1M
Output:$15.00 / 1M
Released:2026-07
Detailed Comparison
| Dimension | Anthropic Claude Sonnet 5 (1M) | OpenAI GPT-5.6 (1M) |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Context window TieTie | 1M | 1M |
| Input price ($/1M) Winner | $3.00 | $5.00 |
| Output price ($/1M) Winner | $15.00 | $30.00 |
| Sample workload cost Winner 1M input + 500K output tokens | $10.50 | $20.00 |
| Released TieTie | 2026-07 | 2026-07 |
| Tokenizer | claude-4 | o200k_base |
The verdict
On the dimensions we measured, Anthropic Claude Sonnet 5 (1M) wins more often - particularly on cost-effectiveness for a typical 1M+0.5M workload.
Anthropic Claude Sonnet 5 (1M) - Key features
The workhorse of the Claude 5 family. Sonnet 5 lands close to Opus 4.8 on coding and agentic benchmarks while staying at the long-standing Sonnet price, with a 1M token context window available by default.
- 1M token context window
- Near-Opus coding quality
- Fast time to first token
- Strong tool use and structured output
- Batch and caching discounts
OpenAI GPT-5.6 (1M) - Key features
The July 2026 refresh of the GPT-5 series. GPT-5.6 keeps GPT-5.5 pricing while improving instruction following, tool-call accuracy and refusal calibration, and it ships with a faster streaming stack.
- ~1M token context window
- Improved instruction following
- Lower refusal rate on benign edge cases
- Batch and Flex at 50%
- Strong terminal and agentic scores
How to choose
- Pick the cheaper model if your workload is mostly straightforward classification, extraction, or summarization.
- Pick the bigger context if you process long documents, large codebases, or multi-document research.
- Pick the more recent release if you need state-of-the-art reasoning quality and don't mind paying a bit more.
- Use both via a routing layer - send simple tasks to the cheaper one and complex tasks to the smarter one. This is the highest-ROI optimization in production AI.
Estimate the real cost of either model for your prompts using our Token Calculator.