> We put a particular focus on improving GPT‑5.4’s ability to create and edit spreadsheets, presentations, and documents.

Nothing infuriates me more than an LLM tool randomly deciding to create docx or xlsx files for no apparent reason. They have to use a random library to create these files, and they constantly screw up API calls and get completely distracted by the sheer size of the scripts they have to write to output a simple documents. These files have terrible accessibility (all paper-like formats do) and end up with way too much formatting. Markdown was chosen as the lingua franca of LLMs for a reason, trying to force it into a totally unsuitable format isn't going to work.

Even with the 1m context window, it looks like these models drop off significantly at about 256k. Hopefully improving that is a high priority for 2026.

$30/M Input and $180/M Output Tokens is nuts. Ridiculous expensive for not that great bump on intelligence when compared to other models.

I was just testing this with my unity automation tool and the performance uplift from 5.2 seems to be substantial.

An important feature is the introduction of tool search, which provides models with a "lightweight list of available tools along with a tool search capability", thereby Making MCP Great Again!

So desperate how they're bumping out these 'updates'

No doubt this was released early to ease the bad press

Remember when everyone was predicting that GPT-5 would take over the planet?

Honestly at this point I just want to know if it follows complex instructions better than 5.1. The benchmark numbers stopped meaning much to me a while ago - real usage always feels different.

> When toggled on, /fast mode in Codex delivers up to 1.5x faster token velocity with GPT‑5.4. It’s the same model and the same intelligence, just faster.

I hate these blog posts sometimes. Surely there's got to be some tradeoff. Or have we finally arrived at the world's first "free lunch"? Otherwise why not make /fast always active with no mention and no way to turn it off?