---
type: "Comparison"
title: "GPT-5.6 Sol vs Claude Opus 5 (2026): Public Challenger vs Anthropic's New Frontier Default"
description: "GPT-5.6 Sol vs Claude Opus 5 in 2026: pricing, Sol/Terra/Luna tiers, coding benchmarks, safety claims and when to route work to each model."
resource: "https://www.contextstudios.ai/comparisons/gpt-5-6-pro-vs-claude-opus-4-8"
language: "en"
tags: ["GPT-5.6 Sol vs Claude Opus 4.8", "GPT-5.6 pricing", "OpenAI Sol Terra Luna", "Claude Opus 4.8 coding", "AI model routing 2026"]
generated:
  by: "process:contextstudios-md/1"
  at: "2026-10-08T20:50:21.870Z"
status: "stable"
---

# GPT-5.6 Sol vs Claude Opus 5 (2026): Public Challenger vs Anthropic's New Frontier Default

This comparison changed again on July 24, 2026: Anthropic replaced Claude Opus 4.8 with Claude Opus 5 at the same $5/$25 per-million-token price, closing much of the gap to Fable 5 and becoming the new default model on Claude Max. That resets the baseline against GPT-5.6 Sol, which publicly launched July 9, 2026 after a US government-coordinated review. Both models are now shipping and purchasable — this is a real head-to-head between two current frontier coding models, decided by capability, price, and operating history rather than availability.

## Detailed Comparison

| Factor | GPT-5.6 Sol | Claude Opus 5 | Winner |
|--------|------|------|--------|
| Availability today | Publicly available since July 9, 2026: full OpenAI API plus ChatGPT Plus/Pro, all three tiers, after US regulatory clearance | Publicly available since July 24, 2026 across the Claude API, Bedrock, Google Cloud, Microsoft Foundry, claude.ai, Claude Code, and Cowork | Tie |
| Coding ceiling | OpenAI claims a Terminal-Bench 2.1 state of the art with max reasoning and ultra subagent mode, independently testable since GA | 96% on SWE-bench Verified at launch — a 7.4-point jump over Opus 4.8's 88.6%, the largest single-generation coding gain on this page | Claude Opus 5 |
| Frontier reasoning and computer-use | No published Frontier-Bench or OSWorld 2.0 results; strongest published claims remain terminal-agent and cyber-focused | 43.3% on Frontier-Bench v0.1 (more than double Opus 4.8's 18.7%) and 70.6% on OSWorld 2.0, beating Fable 5's best computer-use result at a third of the cost | Claude Opus 5 |
| Cybersecurity capability and safeguards | OpenAI's strongest cyber model yet; competitive with Mythos Preview on ExploitBench using about one-third of the output tokens; cleared after government safety review | Anthropic's own safety audit rates Opus 5 the least likely of its current models to behave deceptively, though no equivalent ExploitBench-style claim is published | Tie |
| Price per million tokens | Sol $5/$30; Terra $2.50/$15; Luna $1/$6, plus explicit cache breakpoints and a 90% cache-read discount; also bundled in ChatGPT Plus $20 / Pro $100 | $5/$25 input/output, unchanged from Opus 4.8 despite the capability jump; the new default model on Claude Max | Tie |
| Track record and operating history | Publicly launched July 9, 2026 — over two weeks of broad real-world operating history | Publicly launched July 24, 2026 — the newest frontier model in this comparison, with only days of operating history | GPT-5.6 Sol |
| Independent validation | Launch evals are OpenAI's own; independent Terminal-Bench and ExploitBench replication has had over two weeks to arrive since GA | Launch evals are Anthropic's own and third-party sites (llm-stats.com, BenchLM.ai); independent replication is only just beginning | GPT-5.6 Sol |
| Best immediate decision | Pilot Sol on your hardest coding and security evals and cost-route lighter work to Terra/Luna | Re-run your Opus 4.8 evals against Opus 5 before assuming old routing rules still apply, especially for coding-ceiling and computer-use tasks | Tie |

## Key Statistics

- **OpenAI publicly launched GPT-5.6 Sol, Terra and Luna on July 9, 2026, after the US Department of Commerce cleared a broad release that had been gated since the June 26 preview.** — [CNBC](https://www.cnbc.com/2026/07/08/openai-expanding-gpt-5point6-ai-model-release-ending-government-limits.html) (2026)
- **GPT-5.6 is priced at $5/$30 per 1M input/output tokens for Sol, $2.50/$15 for Terra and $1/$6 for Luna, with explicit cache breakpoints and a 30-minute minimum cache life.** — [OpenAI](https://openai.com/index/previewing-gpt-5-6-sol) (2026)
- **OpenAI says GPT-5.6 Sol sets a new state of the art on Terminal-Bench 2.1 and is competitive with Mythos Preview on ExploitBench while using about one-third of the output tokens.** — [OpenAI](https://openai.com/index/previewing-gpt-5-6-sol) (2026)
- **Claude Opus 5 launched July 24, 2026 at $5/$25 per million input/output tokens, unchanged from Opus 4.8, positioned as the new default model on Claude Max and the strongest model available on Claude Pro.** — [Anthropic](https://www.anthropic.com/news/claude-opus-5) (2026)
- **Claude Opus 5 leads the SWE-bench Verified leaderboard at 96%, a 7.4-point jump over Opus 4.8's 88.6%, ahead of Claude Mythos 5 (95.5%) and Claude Fable 5 (95%).** — [BenchLM.ai](https://benchlm.ai/benchmarks/sweVerified) (2026)
- **Opus 5 scores 70.6% on OSWorld 2.0 and 62.0% on GDPval-AA while keeping Opus 4.8's identical $5/$25 price and 1M-token input / 128K-token output context window.** — [llm-stats.com](https://llm-stats.com/models/compare/claude-opus-4-8-vs-claude-opus-5) (2026)

## Choose GPT-5.6 Sol when...

- Your workload is command-line coding, vulnerability research or long-horizon agent work where OpenAI's Terminal-Bench 2.1 and ExploitBench claims could pay off
- You want the Sol/Terra/Luna tiering to route by cost: Sol for the hardest tasks, Terra and Luna for cheaper high-volume work
- You already live in the ChatGPT/Codex ecosystem and want GPT-5.6 inside ChatGPT Plus/Pro plus full API access
- You want a model with over two weeks of independent, real-world operating history rather than a days-old launch

## Choose Claude Opus 5 when...

- You need the highest available coding ceiling — Opus 5's 96% SWE-bench Verified score is a 7.4-point jump over Opus 4.8 at the same price
- Your workload involves computer-use or frontier reasoning tasks, where Opus 5 posts new highs on OSWorld 2.0 and Frontier-Bench v0.1
- You're already on Claude Max and want Anthropic's new default model without switching providers
- You prefer Anthropic's stable, unchanging published rate card ($5/$25) even as the underlying model's capability jumps

## Our Recommendation

Opus 5 arrived with a bigger coding jump than the prior Opus 4.8 baseline had: SWE-bench Verified rose from 88.6% to 96%, a 7.4-point gain at an unchanged price, and Opus 5 more than doubled Opus 4.8's Frontier-Bench v0.1 score while topping every competing model including Fable 5. GPT-5.6 Sol still brings real, differentiated strengths — OpenAI's own Terminal-Bench 2.1 state-of-the-art claim, ExploitBench results competitive with Mythos Preview at roughly a third of the output tokens, and the Sol/Terra/Luna tiering for clean cost routing ($5/$30, $2.50/$15, $1/$6). Neither wins outright: route high-ambition terminal-agent and security workloads to GPT-5.6 Sol, or cost-optimize with Terra/Luna; lean on Claude Opus 5 for the highest available coding ceiling, computer-use execution, and Anthropic's own safety-audit findings around deception resistance. With Opus 5 only days old and GPT-5.6 Sol's independent benchmark replication still arriving, run your own evals before committing either model to production-critical paths.

## Frequently Asked Questions

**Q: Is GPT-5.6 Sol generally available now?**
A: Yes. After a US government-coordinated review, OpenAI publicly launched GPT-5.6 Sol, Terra and Luna on July 9, 2026. All three tiers are available through the OpenAI API, and the models are included in ChatGPT Plus ($20/mo) and Pro ($100/mo) with usage limits.

**Q: Is Claude Opus 5 the same model as Claude Opus 4.8?**
A: No. Anthropic replaced Opus 4.8 with Claude Opus 5 on July 24, 2026, at the same $5/$25 price. Opus 5 more than doubled Opus 4.8's Frontier-Bench v0.1 score and jumped SWE-bench Verified from 88.6% to 96%, becoming the new default model on Claude Max.

**Q: Which is better for coding right now?**
A: Claude Opus 5 has the higher published coding ceiling: 96% on SWE-bench Verified versus GPT-5.6 Sol's Terminal-Bench 2.1 state-of-the-art claim on a different benchmark. Sol remains the more terminal-agent and security-focused bet. Run both on your own repos before committing either.

**Q: Is GPT-5.6 cheaper than Claude Opus 5?**
A: At the top tier they're close: GPT-5.6 Sol is $5/$30 per 1M input/output tokens versus Opus 5's $5/$25 — Opus 5 is actually cheaper on output. But Terra ($2.50/$15) and Luna ($1/$6) make the GPT-5.6 family cheaper overall for high-volume or lighter work, and both models are also bundled into subscription tiers.