Unsuffixed GPT-5.6 Is Just an Alias for Sol

The mistake

Specifying the unsuffixed gpt-5.6 model id somewhere in a config or API call, expecting it to resolve to some kind of default or auto-selected variant distinct from any of the three named GPT-5.6 models — and being confused when its behavior, price and specs turn out to exactly match one specific named model.

Why this happens

The unsuffixed name reads like it could mean "whichever GPT-5.6 variant is appropriate," similar to how some other vendors handle unversioned aliases that route dynamically based on load or context. That's not what's happening here: the unsuffixed id is documented as an alias that routes to one specific named model, described as roughly corresponding to the unsuffixed tier used in earlier GPT-5 generations. It isn't a smart router across the family — it's a fixed pointer to one member of it.

Why it matters

Anyone comparing "gpt-5.6" against one of the explicitly-named GPT-5.6 models in a cost or capability comparison, expecting to be looking at two different things, is actually comparing a model against itself under two different names. That's a wasted comparison at best, and at worst a source of real confusion if the two entries were expected to diverge and didn't.

The fix

Treat gpt-5.6 and its named target as identical for every pricing, context-window, and behavior purpose — because they are. If your tooling or documentation lists both as if they might be different models, that's worth correcting to avoid presenting a false choice. For clarity in your own configuration, using the explicit named id rather than the alias is generally the better practice — it states plainly which model is actually running rather than relying on a reader already knowing what the alias resolves to.

This is also the detail that explains why the Codex CLI's own startup banner names a specific model rather than the unsuffixed alias — the CLI is telling you exactly which model answered, and it happens to be the same one the alias would have pointed to anyway, which is worth confirming for yourself once rather than taking on faith.

See also

GPT-5.6 Sol — Specs, Pricing & Limits is the actual model both the alias and the explicit id both mean.