GPT-6.1 Sol: A Stronger Sol for Complex Work
RouterHub Team · Updated 2026-09-30

GPT-6.1 Sol is now available on RouterHub as openai/gpt-6.1-sol. OpenAI describes it as an upgrade to GPT-6 Sol, with gains across coding and professional work. For teams evaluating the GPT-6 family, it adds another option for tasks that require sustained reasoning across code, documents, and multiple steps.
What changed with GPT-6.1 Sol?
OpenAI reports improvements across complex coding, document analysis, and multi-step business workflows. In its DeepSWE v1.1 evaluation of long-horizon software engineering tasks, GPT-6.1 Sol scored 6.4 percentage points above GPT-6 Sol’s best result at lower reasoning effort and cost. Compare both models on your own tasks before making a switch.
OpenAI also reports that GPT-6.1 Sol approaches GPT-6 Astra on several evaluations. The useful question for a production team is which work benefits from that additional capability, measured against its current model on the same tasks.
GPT-6.1 Sol at a glance
| Item | Detail |
|---|---|
| Provider | OpenAI |
| RouterHub model ID | openai/gpt-6.1-sol |
| Context window | 1,050,000 tokens |
| Maximum output | 128,000 tokens |
| Input | Text and images |
| Output | Text |
These are OpenAI’s published model specifications. For document-heavy work, use the relevant source material and define what a complete, checkable answer should contain. A large context window does not replace careful task design.
Where should teams try it first?
Code changes. Ask the model to trace an issue across files, make a focused change, and explain what it checked. Review the resulting diff and test outcome, not just the explanation.
Document-heavy analysis. Test questions that require details from tables, charts, or fine print. Check each answer against the source, especially when the model must reconcile conflicting material.
Multi-step workflows. Use a real sequence with clear success criteria. Review whether each observable action moved the task toward a correct completion.
Keep the prompts, inputs, and acceptance criteria consistent when comparing GPT-6.1 Sol with your current model. Record correct completion, review effort, elapsed time, and token use across several representative cases. That evidence will show where the model belongs in your routing decisions.