For agents, the value is clearer still: structured JSON output, reusable commands and built-in skills that let models interact with Workspace data and actions without a custom integration layer.

The big headlines on this release are efficiency, with OpenAI reporting that GPT-5.4 uses far fewer tokens (47% fewer on some tasks) than its predecessors).

OpenAI launches ChatGPT for Excel powered by GPT-5.4, enabling users to build, update, and analyze spreadsheet models using plain language.

ChatGPT is now using its 5.4 Thinking model for deeper reasoning, and it's even better at handling "professional work." ...