Choosing an AI model in October 2026: capability, cost and control
What recent OpenAI and Anthropic model releases mean for business applications, and how to choose using your own evaluation data.
What changed this month?
On 7 October 2026, Anthropic announced Claude Haiku 5.5 for high-volume tasks such as classification, summarisation and support. On 26 October, OpenAI announced GPT-6.1 Terra in its API, highlighting visual reasoning, computer use and writing. These are provider descriptions, not independent evidence that either model is best for your application.
Model names and access change quickly. Check each provider's current documentation, region availability, data terms and pricing before making a commitment.
How should a business choose?
Collect a representative set of real tasks, with sensitive information handled appropriately. Score the outcomes that matter: accuracy against known answers, safe handling of missing information, time to useful response, and the effort needed for human correction.
Test the complete workflow, including retrieval, permissions, tool calls and failure handling. A model that performs well on a public benchmark can still fail on your documents or business rules.
- Compare a small model and a stronger model on the same cases.
- Measure input, output, retries, retrieval and human review costs.
- Test difficult and adversarial cases, not only happy paths.
- Agree acceptance thresholds before rolling out to users.
Where can smaller models help?
A smaller model may be a good candidate for classification, extraction or first-pass routing when a clear answer can be checked. Send ambiguous or higher-impact cases to a stronger model or a person. Routing adds complexity, so measure whether it improves the outcome rather than assuming it saves money.
For document questions, pair generation with appropriately permissioned retrieval and source citations. Model selection cannot compensate for missing source documents or poor retrieval.
An actionable first step
Begin with one workflow and a small, agreed evaluation set. Build a baseline, compare two candidate approaches and review quality, cost, latency and data boundaries before widening scope. BuildrLab can help shape that discovery and deliver the resulting application.
Have a real workflow in mind?
Explore an AI discovery engagement, a focused RAG pilot or fractional engineering support with BuildrLab.