Instafill.ai now runs on GPT-6 Sol
On September 30, 2026, the AI models used across Instafill.ai were upgraded to GPT-6 Sol, the latest Sol model in OpenAI's GPT-6 family. The upgrade is live in every account, and existing forms and Agent workflows use it without any change to your account or setup.
Why we moved to GPT-6 Sol
Instafill.ai work is rarely a single question and answer. The model has to understand source documents, work across several files, follow detailed instructions, decide where each piece of information belongs, and produce the completed form. Reliability, multi-step reasoning and speed all matter for that. OpenAI reports improvements in each of these with GPT-6 Sol compared with GPT-5.6 Sol.
More reliable factual output. On OpenAI's internal factuality evaluation, GPT-6 Sol makes about half as many mistakes as GPT-5.6 Sol. When a model reads source files and uses them to complete a form, the goal is not plausible text. It has to work from the information it was given and carry it into the document accurately.
Stronger on multi-step tasks. OpenAI also reports stronger results on professional, multi-step work, which is how the Instafill.ai Agent operates. One Agent request can mean understanding what you want, finding the relevant form and source files, extracting the information, deciding how it maps into the document, and completing the form. The more of that the model handles reliably in one workflow, the less you have to split a task into separate instructions.
Faster for production work. OpenAI describes GPT-6 Sol as bringing much of GPT-6 Astra's capability to a faster model built for work at scale. We made Sol the primary working model for the demanding AI workloads across Instafill.ai, where speed counts because the model runs repeatedly on real documents, particularly with larger forms or several source files.
What changes for you
Nothing needs to be migrated or set up. If there is a form or an Agent workflow you have not run recently, this is a good time to run it again: the model underneath has changed, and the way you use Instafill.ai has not. GPT-6 Sol is used for the Agent and for document processing.
OpenAI usage tier and data handling
Instafill.ai operates at OpenAI's Tier 5, the highest standard API usage tier, and has built on OpenAI for years. OpenAI does not use API inputs or outputs to train its models by default. AI data handling explains what is sent to AI providers and what is not. For qualified customers working with protected health information, Instafill.ai can enable an OpenAI configuration designed for HIPAA-regulated workflows.
