Stella AI Adds GPT-6.1 Sol, One Week After GPT-6 Sol
SUPERNOVA is positioning a fast-follow model as the near-top-tier option for its business customers, one point off GPT-6 Astra on a third-party index, which narrows the gap between the highest-end model and what Stella AI subscribers can actually use.
Reporting from 1 source: ASCII.jp.
SUPERNOVA Inc. will offer OpenAI's GPT-6.1 Sol through its Stella AI and Stella AI for Biz services starting Monday, October 5, 2026. The model arrived one week after GPT-6 Sol and improves coding, document understanding, and specialized work. On Artificial Analysis's overall intelligence index, dated September 29, 2026, it comes within 1 point of OpenAI's top-tier GPT-6 Astra. OpenAI puts factual errors on highly difficult questions at 7.7%, down from 11.4%.
The rollout starts the same day as the announcement, October 5, 2026, on both the consumer Stella AI service and the business tier, Stella AI for Biz. GPT-6.1 Sol follows GPT-6 Sol by one week.
SUPERNOVA cites Artificial Analysis figures dated September 29, 2026. On the overall intelligence index the new model sits within 1 point of GPT-6 Astra, the top-tier model in OpenAI's lineup. On factual errors for highly difficult questions, OpenAI's own disclosed figure drops from 11.4% to 7.7%. The company describes the update as a performance gain over the previous model in coding, document understanding, and specialized work.
Synthesized by Yomimono from the 1 cited source below, including Japanese-language reporting where cited, then editorially reviewed before publishing.