OpenAI's Ted Sanders shares a rule of thumb for picking the right GPT-model

OpenAI's Ted Sanders has categorized the new GPT-6.1 Terra and explained how the company names its language models. According to Sanders, model performance is multidimensional. A model that's great at math won't automatically be good at jokes. Still, most performance gaps come down to one variable: model size. Sanders says OpenAI's model names are difficult to simplify because model size, reasoning effort, and multi-agent systems are distinct dimensions. Combining them into a single "IQ score" would obscure details.

And size doesn't explain everything. Newer, smaller models can outperform older, larger ones through better training data or improved architectures. GPT-6.1 Terra is likely better than the larger Astra at technical communication and roughly matches it in image processing and computer use at a much lower price point, but falls short in most other areas, Sanders says. "If you care about quality only, pick Astra. If you're a bit price sensitive, pick Sol. If you're very price sensitive, pick Terra or Luna."

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