Claude Sonnet 5.5 and GPT-6.1 Sol bring faster, lower-cost options

Week of September 28, 2026Prepared October 11, 20262 items

Anthropic released Claude Sonnet 5.5 on September 28 as a faster, lower-cost complement to Claude Opus 5.5. On September 29, OpenAI released GPT-6.1 Sol, an upgrade to GPT-6 Sol that it says nearly matches GPT-6 Astra on agentic coding, computer use, and professional work at one-fifth of Astra’s standard API prices.

What to do this week

Both releases add a quicker, cheaper option inside a model family you may already use. A useful habit: try routine, clearly defined tasks, such as summaries and first drafts, on the lower-cost model first, and move up only when the results fall short.

AnthropicFamily additionAnnounced September 28, 2026

Anthropic releases Claude Sonnet 5.5, a faster complement to Opus 5.5

What changed
Sonnet 5.5 is the second model in the Claude 5.5 family. Anthropic calls it “a clear upgrade over Claude Sonnet 5” that “runs 30%+ faster, and costs up to 30% less for most work,” and says it is strongest at well-scoped everyday tasks, while Opus 5.5 “remains clearly stronger at complex, open-ended work requiring sustained judgment.” Developer list prices match Sonnet 5: $2 per million input tokens and $10 per million output tokens.
Who can use it
Available on all platforms, including Amazon Web Services, Google Cloud, and Microsoft Azure, and on the Claude Platform as claude-sonnet-5-5. In Claude Code and Anthropic’s apps, the default effort setting is Medium.
For church offices
Turning approved event details into a newsletter item, or a staff meeting’s action items into a task list, is the kind of well-scoped work Anthropic describes. Staff still review every draft before it goes out.
For businesses
Try it on routine documents, such as a weekly status update, and keep Opus 5.5 for open-ended analysis where the faster model falls short.
Try this: Pick one routine weekly task and compare Sonnet 5.5 with the model you use now on two things: speed, and how much editing the draft needs.

Sources

OpenAIUpgradeAnnounced September 29, 2026

OpenAI releases GPT-6.1 Sol, an upgrade to GPT-6 Sol

What changed
OpenAI describes GPT-6.1 Sol as “an upgrade to GPT-6 Sol that nearly matches GPT-6 Astra’s intelligence on agentic coding, computer use, and professional work at one-fifth of Astra’s standard input and output token prices.” Standard API prices are $2 per million input tokens and $10 per million output tokens, compared with $10 and $50 for GPT-6 Astra.
Who can use it
Plus, Pro, Business, Enterprise, and Edu users in ChatGPT Work and Codex. OpenAI says it is “not yet available in Chat.” Developers can use it in the API as gpt-6.1-sol.
For church offices
If your office uses ChatGPT Work, rerun one task you already trust, such as last month’s newsletter draft or an event checklist, and compare the results before you change any saved instructions.
For businesses
Teams that tested GPT-6 Sol or GPT-6 Astra on recurring reports can rerun the same test and see whether GPT-6.1 Sol is good enough for everyday use at the lower price.
Try this: Rerun two or three tasks you already tested on GPT-6 Sol, with the same instructions, and compare the results side by side.

Sources

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