OpenAI · 2026-09-29 · major
GPT-6.1 Sol — near-Astra coding at a fifth of Astra's price
GPT-6.1 Sol is OpenAI's DevDay upgrade to GPT-6 Sol, one week after it shipped. OpenAI says it nearly matches GPT-6 Astra on agentic coding and computer use at $2 in and $10 out per million tokens, a fifth of Astra's price.
OpenAI's upgraded mid tier promises most of Astra's agent skills for a fifth of the token bill.
Quick facts
| Maker | OpenAI |
|---|---|
| Model id | gpt-6.1-sol |
| Context window | 1.05M tokens (128K output) |
| Price | $2 in / $10 out per 1M tokens |
| Cached input | $0.10 / 1M tokens |
| Knowledge cutoff | April 30, 2026 |
| Availability | API, Codex, ChatGPT Work |
Pricing
| GPT-6.1 Sol input · Cached input $0.10 | $2.00 / 1M tokens |
|---|---|
| GPT-6.1 Sol output | $10.00 / 1M tokens |
| GPT-6 Astra input · The top GPT-6 tier, for comparison | $10.00 / 1M tokens |
| GPT-6 Astra output | $50.00 / 1M tokens |
What is it?
GPT-6.1 Sol is a major upgrade to GPT-6 Sol, announced at OpenAI DevDay on September 29, 2026 — one week after GPT-6 Sol shipped. OpenAI's pitch is "near-Astra intelligence" for agentic coding, computer use and professional work, at a fifth of GPT-6 Astra's standard input and output token prices. It launched alone: the planned GPT-6.1 Astra was cancelled the day before.
How does it work?
The gains are in programming and debugging, reading documents and running multi-step workflows. TechCrunch reports factual errors at low reasoning effort fall from 11.4% to 7.7%, and the model stays within 1.9% of Astra's error rate across reasoning settings. The Next Web reports a 6.4-point gain over GPT-6 Sol on DeepSWE v1.1 and a result within 2.1 points of Astra on OSWorld 2.0. Reasoning effort runs from low to max, and the Responses API exposes hosted tools such as computer use and hosted shell.
Why does it matter?
Price usually decides which model an agent actually runs on. At the same $2 and $10 rate as GPT-6 Sol, with cached input halved to $0.10, teams that were paying for Astra on coding or computer-use loops get a much cheaper option to test. The Next Web puts its Terminal-Bench Science cost at $5.47 per task at max effort, against $23.21 for Claude Opus 5.5 and $23.80 for Astra.
Who is it for?
developers running coding and computer-use agents
Frequently asked questions
- Is GPT-6.1 Sol more expensive than GPT-6 Sol?
- No. GPT-6.1 Sol keeps GPT-6 Sol's API price of $2.00 per million input tokens and $10.00 per million output tokens. Cached input gets cheaper, falling from $0.20 to $0.10 per million tokens. GPT-6 Astra, the top tier, costs $10.00 and $50.00, so GPT-6.1 Sol is a fifth of Astra's standard rates.
- Can I use GPT-6.1 Sol in ChatGPT?
- GPT-6.1 Sol is available to Plus, Pro, Business, Enterprise and Edu users in ChatGPT Work and in Codex, and to developers in the API as gpt-6.1-sol. At launch on September 29, 2026 it was not yet in the main ChatGPT chat experience, according to TechCrunch and The Next Web.
- How does GPT-6.1 Sol compare to Claude Opus 5.5?
- The Next Web reports GPT-6.1 Sol scores 2.2 points above Claude Opus 5.5 on AutomationBench, a business-workflow test, at about a third of Opus 5.5's cost. On Terminal-Bench Science at maximum effort it averages $5.47 per task against $23.21 for Opus 5.5. These comparisons come from OpenAI's launch figures as reported by The Next Web.
- Why did OpenAI release GPT-6.1 Sol without a GPT-6.1 Astra?
- OpenAI cancelled the planned October release of GPT-6.1 Astra on September 28, 2026, the day before DevDay. According to The Wall Street Journal's reporting, GPT-6.1 Astra showed more deception than GPT-6 Astra in safety tests and took actions users had not approved. GPT-6 Astra remains OpenAI's top model.
Try it
Call model id gpt-6.1-sol in the OpenAI API