GPT-5.6 Sol or Claude Sonnet 5?
For API buyers, run your own evaluation set before committing. GPT-5.6 Sol is tightly integrated with OpenAI’s multi-tool ecosystem and effort settings; Sonnet 5 is especially relevant for teams already using Claude Code or Anthropic APIs.
OpenAI agent/coding ecosystem and multiple effort levels
Anthropic/Claude Code workflows with competitive token pricing
GPT-5.6 Sol
Professional API workflows where token cost and reasoning controls matter
Official specification ↗Claude Sonnet 5
Anthropic's fast workhorse model balancing intelligence, speed and price.
Official specification ↗Side-by-side comparison
| Category | GPT-5.6 Sol | Claude Sonnet 5 |
|---|---|---|
| Provider | OpenAI | Anthropic |
| Positioning | Flagship GPT-5.6 tier | Frontier Sonnet generation |
| Availability | ChatGPT eligible paid plans, Work/Codex and API | Claude products and Anthropic API |
| API price note | OpenAI announced a temporary Sol price reduction Aug 21, 2026 | Intro $2/M input + $10/M output through Aug 31; then $3/$15 |
| Coding | Strong coding and agent positioning | Strong coding and Claude Code ecosystem |
| Evaluation advice | Use production-like tests with your effort settings | Use the same task set, tools and latency constraints |
| Company | OpenAI | Anthropic |
| Product category | Product · Reasoning Model | Model · Balanced reasoning model |
| Current pricing note | API / 1M tokens: $4 input, $0.40 cached input, $20 output; long-context/tool charges extra | $2 input, $0.20 cache read and $10 output per 1M tokens |
| Best suited to | Professional API workflows where token cost and reasoning controls matter | Production coding and agents where speed and quality both matter |
| Key capabilities | 1.05M-token context; up to 128K output; Text/image input and text output; Reasoning effort includes none; gpt-5.6 alias routes to Sol | Agentic coding; Adaptive thinking; 1M context; Fast production work |
| Last verified | 2026-09-07 | 2026-09-08 |
| Official product source | https://developers.openai.com/api/docs/models/gpt-5.6-sol | https://platform.claude.com/docs/en/models/sonnet-5/overview |
How we reached this verdict
We looked at the things that affect everyday use: what each product can do, how its plans are structured, where it fits into your existing workflow, and what the provider currently documents. Benchmark results are useful context, but they are not a universal winner score because test settings and tools vary.
Common questions
GPT-5.6 Sol or Claude Sonnet 5: which should I choose?
Choose GPT-5.6 Sol for openai agent/coding ecosystem and multiple effort levels. Choose Claude Sonnet 5 for anthropic/claude code workflows with competitive token pricing. Validate the decision with your own prompts and total task cost.
Is GPT-5.6 Sol cheaper than Claude Sonnet 5?
Pricing units can differ. GPT-5.6 Sol: API / 1M tokens: $4 input, $0.40 cached input, $20 output; long-context/tool charges extra. Claude Sonnet 5: $2 input, $0.20 cache read and $10 output per 1M tokens. Check tool charges, plan limits, caching and long-context rules before comparing totals.
Which is better for coding and agent work?
Capability depends on the selected product surface, tools and harness. GPT-5.6 Sol is positioned for professional api workflows where token cost and reasoning controls matter; Claude Sonnet 5 is positioned for production coding and agents where speed and quality both matter. Run the same repository task on both.
How do their context windows compare?
GPT-5.6 Sol lists Varies by included model and plan; Claude Sonnet 5 lists 1M tokens. A larger limit does not by itself guarantee better retrieval or lower cost.
Official sources
Use these provider pages to confirm current features, pricing and availability.
AI tools change quickly. We checked this page on 2026-08-24. Before you subscribe, confirm the latest price, regional availability and usage limits on the provider website.