Reasoning models from OpenAI, namely o1, o3 and o4-mini, that think longer to tackle science, coding and maths problems. Azure has deprecated all of them, with retirement on 19 November 2026 and GPT-5.6 models as successors.
Read more: Microsoft Learn
In the Ultra Transcenders books
Each book explains o-series in context, with comparison tables and the common traps.
Terms in this definition
- ALL
A DAX function that ignores any filters and gives back every row of a table or every value of the named columns. Used within CALCULATE, it works as a modifier that clears filters, although REMOVEFILTERS states that intent more clearly where it is available.
Related terms
- Azure OpenAI
Use of OpenAI models in Azure, including GPT, o-series, embeddings, image and Whisper, through either a Foundry resource or an Azure OpenAI resource. Content Understanding isn't available from a standalone Azure OpenAI resource.
- Azure OpenAI in Foundry Models
OpenAI models offered by Azure as a fully managed service with guardrails built in, covering GPT-4.1, GPT-5, o-series, image, audio and embeddings. Rather than running infrastructure, you pick a deployment type.
- Reasoning model
Kind of model, for instance the o-series or GPT-5 series, that produces hidden reasoning tokens before its answer. Temperature, top_p and penalty parameters are unsupported, and
max_completion_tokenssets output length. - Vision-enabled chat model
A chat model able to understand images included in the prompt, such as GPT-4o, GPT-4.1, the GPT-5 series and o-series models. An application layer cannot add this capability to a model that handles only text.