Values are comparable only within the scope shown. Runtime, plan, model, invocation mode, and account-specific capacity can change the effective result.
Quick comparison
| Criterion | OpenAI API | Anthropic API | Comparability note |
|---|---|---|---|
| Latest flagship-family context | GPT-5.6 family1,050,000 tokensGPT-5.6OpenAI | Claude 5 family1,000,000 tokensClaude 5 familyAnthropic | Values are model-version specific and can change with new releases. |
| Maximum output | GPT-5.6 family128,000 tokensGPT-5.6OpenAI | Claude 5 family128,000 tokensClaude 5 familyAnthropic | A maximum output value is not a guarantee that every request will or should generate that amount. |
| Rate-limit shape | RPM/RPD/TPM/TPD and other model-specific metricsVaries by model and usage tierAll API organizationsOpenAI | RPM, input TPM, output TPMRPM + input TPM + output TPMUsage-tier and model specificAnthropic | Use each provider's console or headers for the account's current numeric capacity. |
Which is best for your requirement?
Very large current context
Both current flagship families exceed one million tokens by a small margin; test quality and latency on representative inputs.
Capacity planning
Model request rate, input throughput, output throughput, cache behavior, and burst shape separately.
Vendor resilience
Build explicit provider-specific adapters; do not assume limit or error semantics are interchangeable.
Validate the decision with your workload
Before choosing between OpenAI API and Anthropic API, reproduce the comparison with the exact plans, models, regions, runtimes, and invocation paths you intend to operate. The reviewed rows cover latest flagship-family context and maximum output and rate-limit shape; they do not turn different pricing, reliability, developer experience, or ecosystem tradeoffs into one universal score.
- Capture representative request sizes, token usage, duration, concurrency, storage, and failure behavior at realistic percentiles.
- Test the boundary and the recovery path on both candidates, including throttling, timeouts, partial failure, retries, and cost controls.
- Record which scoped observation drove the choice and recheck its official source before migration or a major traffic increase.
Official sources
Related