ChatGPT
GPT-5.6 Sol / Terra / Luna — OpenAI
OpenAI's reasoning powerhouse, now split into three price tiers. 1.05M context and 128K output across all of them, with Sol leading the Coding Agent Index at 80 points. The model that mainstreamed chain-of-thought for the rest of us — now with a pricing sheet you actually have to read.
Released
Jul 9, 2026
Context
1.05M tokens
Starting Price
$20/mo (Plus)
Max Output
128K tokens
01
Overview
ChatGPT needs no introduction — it's the model that put AI in everyone's hands. GPT-5.6 landed July 9, 2026, and it's the release where OpenAI stopped shipping one flagship and started shipping a menu.
Three tiers, one architecture. Sol is the flagship for complex coding, research, and design work — $5 / $30 per million tokens. Terra is the balanced everyday model for production agents and analysis at $2 / $12. Luna handles extraction, classification, and high-volume transformations for $0.20 / $1.20. All three share a 1.05M token context window, 128K max output, and a February 16, 2026 knowledge cutoff.
What's actually new beyond the tiering: programmatic tool calling (Sol coordinates JavaScript in a hosted runtime instead of round-tripping every tool call), multi-agent support through the Responses API, prompt caching with explicit breakpoints, and noticeably stronger design and visual-hierarchy work. Native computer use carries over from the 5.4/5.5 line.
On benchmarks Sol scores 59 on Artificial Analysis's Intelligence Index v4.1 — a point behind Claude Fable 5 at 60 — but it takes the Coding Agent Index outright at 80 points. SWE-bench Pro comes in at 64.6% for Sol, 63.4% Terra, 62.7% Luna, which is a remarkably small spread across a 25x price range.
Read the plan table carefully, because access is not what you'd assume. Sol is paid-only. In standard ChatGPT conversations the Free and Go tiers still default to GPT-5.5 Instant — they can reach Terra inside Codex and Work, but they can't select Terra or Luna in a normal chat. Plus, Pro, Business, and Enterprise get all three.
02
Key Capabilities
Three Price Tiers, One Architecture
Sol ($5/$30), Terra ($2/$12), Luna ($0.20/$1.20). SWE-bench Pro spread is only 64.6% / 63.4% / 62.7% across a 25x price range — start on Luna and move up only where evals justify it
Programmatic Tool Calling
Coordinates tools with JavaScript in a hosted runtime rather than round-tripping every call through the context window — fewer tokens, less latency on multi-step work
Native Computer Use
Control desktops directly — click, type, navigate software. End-to-end automation across tools until a task is finished.
1.05M Token Context
1,050,000-token window with 128K max output on all three tiers. Requests past 272K input tokens bill at higher long-context rates ($10/$45 on Sol)
Multi-Agent via Responses API
Native multi-agent orchestration plus prompt caching with explicit breakpoints — cached input runs at a 90% discount
Reasoning Tokens
Supports reasoning tokens for chain-of-thought workloads where deeper deliberation matters
Finance-Focused Enterprise Bundle
Native Excel and Google Sheets plugins for financial workflows
Persistent Multi-Round Search
More thorough web search across multiple sources
03
Pricing
| Tier | Price | Details |
|---|---|---|
| Free | $0 | Defaults to GPT-5.5 Instant in standard chat. Terra reachable inside Codex and Work only. Tight limits. |
| ChatGPT Go | $8/mo | Same model access as Free (5.5 Instant in chat, Terra in Codex) + 10x more messages. |
| ChatGPT Plus | $20/mo | All three GPT-5.6 tiers. The real entry point for Sol. |
| ChatGPT Pro | $200/mo | Highest Sol limits and the heaviest reasoning modes. Dedicated GPU slice for faster inference. |
| ChatGPT Business | $25/user/mo | All three GPT-5.6 tiers with higher limits. Pro available as add-on. |
| Enterprise | Custom | Full access, security, compliance features. |
| API — GPT-5.6 Sol | $5 / $30 per 1M tokens | Flagship. Complex coding, research, design. 1.05M context, 128K max output. |
| API — GPT-5.6 Terra | $2 / $12 per 1M tokens | Balanced. Everyday production agents, analysis, and coding. |
| API — GPT-5.6 Luna | $0.20 / $1.20 per 1M tokens | Cheapest. Extraction, classification, high-volume transformations. |
| API — Long context | $10 / $45 (Sol) | Requests over 272K input tokens bill at elevated long-context rates. |
| API — Cached input | 90% off | Cache writes bill at 1.25x input. Batch and flex rates also available. |
04
Best Use Cases
Desktop and browser automation via native computer use
Enterprise workflows involving spreadsheets, presentations, and documents
Complex research requiring persistent multi-round web searches
Professional coding — Sol tops the Coding Agent Index at 80
Tasks requiring long-context planning and execution
Multimodal document parsing and visual understanding
Organizations needing flexible pricing from free to enterprise
05
Pro Prompts
Strategic Planning
Plan a complete marketing strategy for a SaaS launch, including contingencies for each stage. Start with the riskiest assumptions.Computer Use
Open the Q4 sales spreadsheet, filter for deals over $50K, export a summary CSV, and draft an executive email highlighting the top 5 deals by revenue.Research Synthesis
Search for the latest developments in [field] from the past month. Cross-reference at least 5 sources. Highlight where sources disagree and rate your confidence in each finding.Code Review
Review this pull request for security, performance, and standards issues. Report every finding, including low-confidence and low-severity ones — don't filter for importance here. Tag each with a confidence level and severity so I can rank them myself.Tier Routing (GPT-5.6)
Here's my pipeline: [describe the steps]. For each step, tell me whether Sol, Terra, or Luna is the right tier and why. Assume I'll only pay for Sol where the quality difference actually shows up in the output.06
Limitations
Hallucinations keep dropping generation over generation, but they aren't zero — and the remaining errors still land with confidence
Overactive safety guardrails can block legitimate professional requests (false positives)
Three tiers means three decisions. Defaulting everything to Sol is the easy mistake — and a 25x price mistake, given Luna lands within 2 points on SWE-bench Pro
Long-context billing bites: past 272K input tokens, Sol jumps from $5/$30 to $10/$45 — the 1.05M window isn't uniformly priced
Sol at $5/$30 isn't cheap — Grok 4.5 ($2/$6) and Gemini 3.6 Flash ($1.50/$7.50) undercut it heavily for cost-sensitive workloads
Sol is paid-only, and Free/Go standard chat still runs GPT-5.5 Instant. Plus ($20/mo) is the real entry point for GPT-5.6
OpenAI plans to introduce ads in the free and Go tiers
07
Multimodal Capabilities
Input
- Text
- Images (full-resolution support)
- File uploads (documents, PDFs, spreadsheets)
Computer Use
- Native desktop control
- Screenshots
- Mouse and keyboard input
Output
- DALL-E image generation within ChatGPT
- Multi-round persistent web search
Not Supported
- No native audio or video input processing
- Separate Whisper/TTS models handle audio
08
Recent Updates
Jul 30, 2026
OpenAI adjusted GPT-5.6 pricing — Terra down 20%, Luna down 80%. Worth re-running your cost model if you priced it at launch.
Jul 9, 2026
GPT-5.6 became generally available — Sol, Terra, and Luna, all with 1.05M context and 128K max output
Jul 8, 2026
GPT-Live introduced — a new generation of voice models now powering ChatGPT Voice
May 5, 2026
GPT-5.5 Instant became the default ChatGPT model — and on Free and Go, it still is
Launch Win
Sol leads the Artificial Analysis Coding Agent Index at 80 points, and scores 59 on Intelligence Index v4.1 — one point behind Claude Fable 5
On Deck
OpenAI is prepping a new family reportedly codenamed Astra for long-running tasks — unclear whether it lands as GPT-6 or another 5-series entry
Carries Over
Native Computer Use, Tool Search, and the finance-focused enterprise bundle (Excel/Sheets plugins) carry over from the 5.4/5.5 line