AI glossary
Frontier model
One of the most capable AI models available at a given moment, the kind that pushes the state of the art.
“Frontier” is the label companies use for their top models: the ones that set new records on benchmarks and are the first to show new abilities. In October 2026 that includes models such as Claude Fable 5.1 and Opus 5.5, GPT-6 Astra and Gemini 4 Argon.
The term also matters for regulation: rules like the EU AI Act set extra obligations for the most powerful general-purpose models. A frontier model is usually the most expensive option, so it is worth checking whether a smaller one is good enough for your task.
Example: To review a fifty-page contract you use a frontier model. To label thousands of emails, a small, cheap one like Claude Haiku 4.5 or GPT-6 Luna does the job for far less.
In practice
- Check current prices and context windows in our model comparison.
- The frontier moves fast: today’s frontier model will be mid-range in a few months.
- Test with your own task before paying for the most expensive model.
What each family and name means: AI model guide.