For developers doing long coding and document work, it promises near-Astra results at a fifth of the cost; Ultrafast needs the $500 Pro plan.

Kenning's take

What it does

GPT-6.1 Sol is an OpenAI model for complex coding, computer use and professional work that OpenAI says comes close to GPT-6 Astra at lower cost. It has a 1.05M-token context window and supports sub-agents in beta through the API. It is in the API and in Codex and ChatGPT Work, with an Ultrafast mode on some plans.

• 1.05M-token context window
• Near-Astra quality at lower cost
• Multi-agent support in beta
• Ultrafast mode
• US and EU data residency

Who it suits. Developers and teams doing long coding and document work who want Astra-like results for less.

Key facts

Category

AI models

Part of

ChatGPT

Made by

OpenAI

Based in

United States

Released

29 September 2026

How to get it

OpenAI API (model gpt-6.1-sol); Codex and ChatGPT Work depending on plan; Ultrafast on Pro $500 and eligible Enterprise and Edu plans

Works on

ChatGPT Work and Codex, API

In the UK

Yes

API price

$2 per million input tokens, $10 per million output (Ultrafast 6x)

FAQ

Facts from the maker's own pages and the sources listed. Checked 2026-10-11.