GPT-5.6: Frontier intelligence that scales with your ambition

OpenAI announced the general availability release of the GPT-5.6 family of models on July 9, 2026. The release includes Sol, Terra, and Luna models. OpenAI said GPT-5.6 Sol achieves state-of-the-art results across coding, knowledge work, cybersecurity, and science while using fewer tokens and at lower estimated cost than previous and competing frontier models. The company introduced ultra as a highest-capability setting that coordinates multiple agents across parallel workstreams to finish complex tasks faster. OpenAI stated that GPT-5.6 Sol sets a new high of 53.6 on Agents' Last Exam, eclipsing Claude Fable 5 by 13.1 points. On the Artificial Analysis Intelligence Index, GPT-5.6 Sol with max reasoning comes within one point of Fable 5 while completing tasks in 61% less time at roughly half the estimated cost. OpenAI noted that GPT-5.6 launches with safeguards designed to be resilient against determined and adaptive misuse without broadly limiting legitimate work. The company said it put the models and safeguards through an extensive evaluation period combining human red teaming with large-scale automated testing before general availability. OpenAI added that during the preview, it worked closely with expert organizations and trusted partners to pressure-test defenses and strengthen safeguards before broader launch. The resulting system includes protections trained into the model with real-time checks, monitoring, and access calibrated to trust and risk. OpenAI said GPT-5.6 Sol is its best coding model yet, setting a new state of the art at 80 on the Artificial Analysis Coding Agent Index, 2.8 points above Fable 5, while using less than half the output tokens, taking less than half the time, and costing about one-third less. The company stated that GPT-5.6 can write and run lightweight programs that coordinate tools, process intermediate results, monitor progress, and choose the next action as work unfolds. OpenAI explained that ultra goes further by coordinating four agents in parallel by default, trading higher token use for stronger results and faster time-to-result on demanding tasks. The company said developers can build ultra-like experiences using the multi-agent beta in the Responses API. OpenAI shared quotes from Oskar Schulz of Cursor, Itamar Friedman of Qodo, Simon Last of Notion, and Scott Wu of Cognition regarding their evaluations of GPT-5.6 on various benchmarks.