







The main breakthrough of GPT-5 was to route your messages between a couple of different models to give you the best, cheapest & fastest answer possible.This is cool but imagine if you could do this not only for a couple of models but hundreds of them, big and small, fast and… pic.twitter.com/ww2ApYTN3D— clem 🤗 (@ClementDelangue) October 17, 2025
Previewing Ultrafast mode: GPT-5.6 Sol at up to 14X the speed
Preview Ultrafast, a new OpenAI API service tier that runs GPT-5.6 Sol up to 14× faster. Powered by Cerebras, it delivers up to 750 output tokens per second.

OpenAI introduces 'Ultrafast,' a new mode that makes GPT-5.6 Sol work at 14x the speed | TechCrunch
OpenAI is launching a preview of a sped up version of its latest, most powerful model, in an effort to court enterprise users.

Model Release Notes | OpenAI Help Center
We’re beginning the rollout of GPT-5.6 Sol in ChatGPT, our flagship reasoning model for complex work across coding, research, science, cybersecurity, computer use, and design.GPT-5.6 Sol is rolling out to eligible paid ChatGPT plans. Free, Go, and logged-out users are not included. Availability may vary during rollout, and managed-workspace access can depend on administrator settings. Availability for other GPT-5.6 family models varies by product and plan; check the model picker or current rate card in the product you use.

Small Models Have Arrived
For the past few weeks, I've been playing with gpt-5.6-luna. It is shockingly capable, fast, and smart. I regularly see it do ~100 tps, and rip around my codebase, email, and knowledge base.

ChatGPT Work with GPT-5.6
ChatGPT Work, powered by GPT-5.6, helps teams take on ambitious work and turn goals into finished outputs. Connect tools, automate tasks, and keep projects moving.

Building with Open Models
GPT-5.5: Capabilities and Reactions
The system card for GPT-5.5 mostly told us what we expected.

GPT-5.6 Preview System Card - OpenAI Deployment Safety Hub
GPT-5.6 is a new family of three models: Sol, our new flagship model; Terra, a capable lower-cost option; and Luna, our fastest and most cost-efficient model. The safeguards we have built for this launch -- our most robust yet -- are built to deliver these models safely and at scale, around the world.

Introducing GPT-5.4
Introducing GPT-5.4, OpenAI’s most most capable and efficient frontier model for professional work, with state-of-the-art coding, computer use, tool search, and 1M-token context.

GPT-5.6 System Card - OpenAI Deployment Safety Hub
GPT-5.6 is a new family of three models: Sol, our new flagship model; Terra, a capable lower-cost option; and Luna, our fastest and most cost-efficient model. The safeguards we have built for this launch—our most robust yet—are built to deliver these models safely and at scale, around the world.

Previewing GPT-5.6 Sol: a next-generation model
OpenAI previews GPT-5.6 Sol, a next-generation model with stronger capabilities in coding, science, and cybersecurity, paired with its most advanced safety stack.

Accelerating GPT-5.6 Sol Ultrafast with OpenAI
Cerebras powers OpenAI’s GPT-5.6 Sol Ultrafast in the OpenAI API, delivering frontier intelligence at real-time speeds for critical AI work.

Better Call Sol The Workhorse
OpenAI’s GPT-5.6-Sol is finally here, along with the cheaper Terra and Luna.

OpenAI on Twitter / X
GPT-5 is here.Rolling out to everyone starting today.https://t.co/rOcZ8J2btI pic.twitter.com/dk6zLTe04s— OpenAI (@OpenAI) August 7, 2025