With ClaudeOpus 5 landing at the top of the independent leaderboards and OpenAI’s GPT-5.6 lineup maturing, the “which frontier model do I pay for” question is really down to these two. Both now ship a 1M-token context window; both are genuinely excellent. The differences are about shape — how each is packaged, priced, and tuned — not a simple smarter-than gap.
The 20-second answer
- Top raw intelligence & agentic coding, best value at the frontier: Claude Opus 5.
- Breadth — voice, images, tiered pricing, huge ecosystem: GPT-5.6.
Side by side
| Claude Opus 5 | GPT-5.6 | |
|---|---|---|
| Maker | Anthropic | OpenAI |
| Lineup | Single flagship | Sol / Terra / Luna tiers |
| Independent rank | #1 Intelligence & Agentic | Top tier (Sol) |
| Context window | 1M tokens | 1M tokens |
| Flagship price (in/out per 1M) | $5 / $25 | ~$5 in (Sol) |
| Cheaper tiers | Effort dial (low→max) | Terra ~½ cost, Luna cheapest |
| Native voice & images | Text-first | Yes |
| Best at | Coding, agents, long reasoning | All-round, multimodal |
Pricing and benchmarks move fast — check each vendor for current figures.
Claude Opus 5 — the capability & value leader
Opus 5 tops both of Artificial Analysis’s independent boards — the Intelligence Index and the Agentic Index — on launch, and it does so at the same $5 / $25 per-million pricing as Opus 4.8, roughly half what Fable 5 cost for comparable output. Its standout for practitioners is the new effort setting: dial reasoning up for a hard problem, down for a cheap one, per request. If your work is coding, agentic multi-step tasks, or anything long-horizon, it’s the strongest option available right now — and the best value at the frontier.
GPT-5.6 — the versatile ecosystem
GPT-5.6 answers a different question: not “what’s the single best model” but “what covers the most ground.” The three-tier lineup lets you match spend to the job — Sol for hard reasoning, Terra for prior-gen quality at about half the cost, Luna for fast everyday work — and it comes wrapped in the broadest product on the market: voice, image generation, code execution, custom GPTs, and agentic tasks, used by hundreds of millions of people. For a team that wants one vendor to do everything, that breadth is the pitch.
How to decide
- Serious coding or autonomous agents → Opus 5.
- Best value on the hardest reasoning → Opus 5 (effort dial).
- You need voice or image generation in the same tool → GPT-5.6.
- You want tiered pricing to control cost at scale → GPT-5.6 (Terra/Luna).
- One assistant for a whole non-technical team → GPT-5.6.
Many teams run both and route by task: Opus 5 for the engineering and agent work, GPT-5.6 for multimodal and general use. If you can only pick one, decide by whether your hardest problems are coding and reasoning (Opus 5) or range (GPT-5.6).
The bottom line
Right now Opus 5 is the model to beat on raw capability and value, and GPT-5.6 is the most versatile package. Neither is a wrong answer — and given the pace (this is Anthropic’s fourth model in two months), both will likely be leapfrogged again soon. For the wider field, see our which AI model should you use guide and the best AI chatbots ranking.
Comparing something else? Build any pair on our comparison pages, or track new model drops in the Latest in AI feed.