OpenAI has announced the GPT-5.6 series, reshaping the landscape of artificial intelligence! We are looking at a completely new approach to reasoning and problem-solving, not just a model update. This next generation comes in three distinct options: Sol, Terra, and Luna.

What will these new models change in our lives? How are they making leaps in coding, biology, and cybersecurity? Let’s dive into the details!

The GPT-5.6 Series: Sol, Terra, and Luna

OpenAI introduced three models tailored to different needs:

  • Sol: The flagship of the series. Designed to solve the most complex problems.
  • Terra: A balanced option for everyday tasks. It offers performance close to GPT-5.5 but is 2x cheaper.
  • Luna: The most logical choice for those seeking speed and affordability.
GPT-5.6 Ultra Mode and Max Reasoning Effort
GPT-5.6 introduces the “max reasoning effort” feature. This allows the model to dedicate more time to complex problems. Additionally, a brand new Ultra Mode is activated, which leverages subagents for tasks that exceed the capabilities of a single agent!

Pushing the Boundaries in Coding and Cybersecurity

Great news for developers! GPT-5.6 Sol has set a new record on TerminalBench 2.1, which tests command-line workflows. It is far ahead of its competitors in coding tasks that require planning, iteration, and tool coordination.

TerminalBench 2.1GPT-5.6 Sol UltraGPT-5.6 SolClaude Mythos 5GPT-5.6 TerraClaude Fable 5GPT-5.5GPT-5.6 LunaClaude Opus 4.8Gemini 3.1 Pro Preview0%25%50%75%100%Score91.9%88.8%84.3%82.5%83.4%88.0%84.3%78.9%70.7%
TerminalBench 2.1 Scores, source: OpenAI

On the cybersecurity front, it has become a powerful weapon for defenders. The model is highly capable of finding security vulnerabilities, but it is restricted from autonomously executing end-to-end malicious attacks.

GPT-5.6 Cybersecurity Testing: Over 700,000 Hours
OpenAI announced that it conducted over 700,000 A100 GPU hours of automated “red-teaming” to secure the model. This significantly minimizes the risks of misuse.

2x Cheaper Pricing and Incredible Speed

OpenAI has strongly focused on reducing costs in this new series. The Terra model offers performance competitive with the previous generation, GPT-5.5, while being exactly 2x cheaper!

There are pricing solutions suitable for every budget. Prices per 1 million tokens are as follows:

  • Terra (Balanced - 50% Cheaper): $2.50 input / $15 output
  • Luna (Most Affordable): $1 input / $6 output
  • Sol (Flagship): $5 input / $30 output
Prompt Caching Discount up to 90%
With GPT-5.6, prompt caching is also supported. When you read previously cached data, a 90% discount is applied to the cached input costs. This means incredible savings, especially for large-scale projects!

Furthermore, a version reaching a speed of 750 tokens per second on Cerebras will be offered to a limited number of customers in July. This speed is truly incredible for the AI world!

Conclusion

The GPT-5.6 series promises a smarter, safer, and more accessible AI ecosystem. Especially the Ultra Mode working with autonomous subagents could completely change how we work in the future.

What do you think about these new models? Which feature of GPT-5.6 would you like to use in your projects? Let’s meet in the comments! 👇

AI-Generated Content Notice
This blog post is entirely generated by artificial intelligence. While AI enables content creation, it may still contain errors or biases. Please verify any critical information before relying on it.