OpenAI GPT-5.6

GPT-5.6 Token Counter

Analyze prompts for the GPT-5.6 family, including Sol, Terra, and Luna, with a compatible o200k_base tokenizer view.

Accuracy note

Compatible encoding view. Final API usage can include model-side formatting, tools, images, and reasoning tokens that are not represented here.

Frequently asked questions

Which GPT-5.6 model does this page use?

The interactive tool starts with GPT-5.6 Sol. You can switch to Terra or Luna from the model menu.

Is this the same as billed API tokens?

It is a compatible tokenizer view, not a billing guarantee. Structured messages, tools, images, and provider-side processing can change API usage.

Does GPT-5.6 have a 1M context window?

The GPT-5.6 family supports an approximately 1.05 million-token context window; consult the official model page for current limits.