GPT-5.6 Is Here — Try It Free on Felo AI for 7 Days
OpenAI just released GPT-5.6 Sol, Terra, and Luna. Felo Pro subscribers get a limited-time 7-day free trial. See what makes it different and how to try it.
OpenAI dropped GPT-5.6 on July 8, and it is already changing how people think about model selection. Felo AI now has the full GPT-5.6 family — Sol, Terra, and Luna — running in our search and reasoning pipeline.
Felo Pro subscribers get 7 days of GPT-5.6 free, starting now. No credit card, no catch. Head to felo.ai/tools/gpt-56 and start asking.
What Is GPT-5.6?
GPT-5.6 is not one model. It is three:
- Sol — the flagship. Built for serious coding, multi-step reasoning, agentic workflows, and cybersecurity. It introduces a new max reasoning effort and an ultra mode that deploys subagents for complex tasks.
- Terra — the balanced tier. Roughly as good as GPT-5.5 at about half the cost. The right choice for most everyday work.
- Luna — the fast tier. For high-volume tasks where speed and cost matter more than peak reasoning.
This is the first time OpenAI has organized its models around durable tiers instead of dropping a single "best model." The naming scheme matters because it shifts the question from "which model is smartest" to "which model fits this job."
What Makes GPT-5.6 Different
OpenAI says GPT-5.6 is built for work that does not fit into a short chat turn. Here is what that actually means.
Reasoning that holds together
GPT-5.6 is designed for problems that need planning before answering. Break down ambiguous tasks, compare options, weigh trade-offs, and produce structured outputs that survive multiple turns. It keeps context across documents, codebases, and research material better than GPT-5.5.
Coding and agent workflows
This is Sol's strongest area. It set a new record on Terminal-Bench 2.1 for command-line tasks that require planning, iteration, and tool coordination. The model can write and run lightweight programs that coordinate tools, track progress, and decide the next step as work unfolds.
Artificial Analysis found GPT-5.6 Sol scoring just 1 point behind Claude Fable 5 on their Intelligence Index — at about one-third of the cost.
Long-context work
The 400K token context window means more source material in a single session: reports, PDFs, meeting transcripts, product docs, technical references. GPT-5.6 summarizes, compares, extracts, and rewrites without losing the thread.
What People Are Saying
Reaction from the developer community has been active. A few patterns stand out:
The trust gradient shifted. Several developers reported that GPT-5.6 Sol changed how they review AI-written code. Instead of checking every line for basic competence, they now review at the diff level — architecture decisions, edge cases, whether the result matches what they actually wanted. One developer wrote: "I still review important code before shipping, but I'm no longer babysitting every line. Most of the time I'm reviewing it like I'd review a strong teammate's PR."
Front-end design got better. Previous models could generate UI components but often lost visual consistency across files. Users say Sol is better at layout, spacing, responsive behavior, and making things feel designed rather than assembled.
The cost conversation changed. At roughly a third of Claude Fable 5's cost while scoring within 1 point on independent benchmarks, GPT-5.6 Sol is pushing people to think about cost per completed task instead of cost per token. Terra and Luna push that spectrum even further.
Not a clear winner yet. Some users point out that Sol still trails Fable 5 on analytical quality and rubric scores. The working consensus seems to be: Sol is excellent for coding and knowledge work, Fable 5 may still have the edge on deep product and long-running projects. Worth trying both.
How GPT-5.6 Works Inside Felo AI
Felo gives you a straightforward way to try GPT-5.6 without managing API keys or building your own model router.
Here is what you can do with it:
- AI search with stronger reasoning — Complex questions get source-backed answers with more careful thinking behind them.
- Model comparison — Test GPT-5.6 against other models in Felo before committing to a workflow.
- Coding — Plan, debug, and iterate on code with a model that understands repository-level context.
- Document work — Process long PDFs, transcripts, notes, and reports without losing continuity.
- Technical research — Turn specs, papers, changelogs, and engineering notes into clear decisions.
How to Try It
Getting started takes about a minute:
- Go to felo.ai/tools/gpt-56 — or the direct GPT-5.6 search link.
- Sign in — Free registration if you do not have a Felo account yet.
- Select GPT-5.6 — Choose the model in the Felo search interface.
- Start testing — Bring coding tasks, research folders, launch briefs, or comparison prompts.
- Use it for 7 days — Felo Pro subscribers get a limited-time free trial. No credit card required.
GPT-5.6 vs GPT-5.5: Worth the Switch?
GPT-5.5 made long-context and agentic work practical. GPT-5.6 pushes it further: stronger reasoning, cleaner coding support, and better results on complex tasks.
The difference shows up in the loop. Fewer clarification rounds, fewer broken first drafts, fewer restarts, less review overhead. The model uses tokens more efficiently while producing better output.
If your daily work involves multi-step reasoning, code changes across files, or documents that usually take several tools to process, GPT-5.6 is worth testing against what you are using now.
Start Your Free Trial
OpenAI's newest model, available inside Felo AI. Felo Pro subscribers get 7 days free.
You can also test GPT-5.6 with your own prompts in the Felo LLM Playground — compare it side by side with GPT-5.5, Gemini, Claude, and other models before deciding which one to use for serious work.