In short: GPT-5.6 went public on July 9, 2026. Three models: Sol (flagship, $5/$30 per million tokens), Terra ($2.50/$15), Luna ($1/$6). OpenAI's flagship is half the price of Claude Fable 5. Max and ultra modes for complex tasks. Real-time translation included.
What Happened
On July 9, 2026, OpenAI released GPT-5.6 to the public. The model was announced on June 26 but spent two weeks in a limited preview — at the request of the US government, the models were first shown to government agencies (source: OpenAI).
Instead of one model, OpenAI released three: Sol (flagship), Terra (mid-tier), and Luna (budget). Each is designed for different task types and budgets.
Three Models — Which One Is for What
Sol is the most powerful model in the lineup. Built for complex reasoning, extended coding sessions, agent-driven workflows, and security-focused tasks. Features max mode (deep thinking) and ultra mode (automatic sub-agent deployment for complex task decomposition).
Terra is the mid-tier model that, according to OpenAI, performs at the level of the previous flagship GPT-5.5 but costs half as much. The optimal choice for most business tasks.
Luna is the fastest and cheapest. Built for high-volume operations: classification, data extraction, request routing, first drafts. Where you need many cheap calls instead of a few expensive ones.
Price Comparison with Claude
Prices are per 1 million tokens (approximately 750,000 words).
| Model | Input | Output | Best For |
|---|---|---|---|
| GPT-5.6 Sol | $5 | $30 | Complex reasoning, agents, security |
| GPT-5.6 Terra | $2.50 | $15 | Most business tasks |
| GPT-5.6 Luna | $1 | $6 | High-volume operations, classification |
| Claude Fable 5 | $10 | $50 | Complex reasoning, code |
| Claude Sonnet 5 | $2 | $10 | Agent tasks, everyday tasks |
OpenAI's flagship Sol ($5/$30) costs exactly half of Anthropic's Claude Fable 5 ($10/$50).
Benchmarks
Terminal-Bench 2.1 (complex task benchmark):
- GPT-5.6 Sol — 88.8%
- GPT-5.6 Sol Ultra — 91.9%
- Claude Fable 5 — 84.3%
- Claude Opus 4.8 — 78.9%
ExploitBench (cybersecurity) — Sol matches Mythos (the unrestricted version of Fable 5) while using three times fewer resources.
Real-Time Translation
OpenAI added a real-time translation feature. Place your phone on the table, start speaking — it translates the conversation synchronously.
For businesses with international partners or clients, this could replace an interpreter in meetings.
What This Means for Your Business
1. Competition = cheaper tools for you. When OpenAI and Anthropic compete, business users win.
2. Don't choose a model by name. The question isn't "which model is best" but "which model pays off in your specific process." Terra at $2.50 may handle 90% of your tasks as well as Sol at $5.
3. Sub-agents are the next step. Ultra mode means AI can decompose complex tasks and solve each part separately — like a manager delegating to a team.
FAQ
Should I migrate from Claude to GPT-5.6? Not necessarily. If Claude handles your tasks well, migration for migration's sake doesn't make sense. Compare cost and quality on your specific process.
Which GPT-5.6 model is best for small business? Terra. It performs at the previous flagship level but costs half as much ($2.50/$15).
Is GPT-5.6 safe for client data? OpenAI positions cybersecurity as a key Sol advantage. But the general rule stands: don't upload full client databases without proper protection. Use the API with encryption, not the web interface.
What is ultra mode? Ultra is when AI launches "sub-agents" to solve complex tasks. For example, you ask it to analyze competitors — AI breaks this into data collection, price analysis, comparison, and a summary report.