Claude Opus 5 is here
Claude Opus 5 is Anthropic's flagship model in the main Claude lineup: the successor to Opus 4.8 and the top of the "Haiku → Sonnet → Opus" ladder. The model became available in summer 2026 and is already in the GPTunneL catalog: open Claude Opus 5 and use it right in your browser — no subscription required.
There was no revolution, and that's fine: Opus 5 continues the Opus 4.8 line with a focus on long, demanding tasks. But the key leaks were confirmed: context up to one million tokens and a stronger reasoning mode. Here's what the model can do, who it's for, and when Sonnet is the smarter pick.
What Claude Opus 5 can do
According to the GPTunneL catalog, the model ships with a full top-tier feature set:
- Context up to 1M tokens — an entire codebase, a book, or a stack of contracts fits into a single conversation.
- Reasoning mode (thinking) — the model "thinks" before answering; the harder the task, the bigger the payoff.
- Code — the strong suit of the whole Opus line: generation, review, refactoring, and agentic environments like Claude Code.
- Agentic workflows and tools — function calling, multi-step action chains, and web search for fresh data.
- Vision — understands images: screenshots, diagrams, documents.
In practice this is a model for tasks where depth matters more than speed: architectural decisions in code, legal and financial analysis, research across large volumes of sources.
The Opus lineup in 2026: 4.7, 4.8, and 5
Three generations of the flagship live in the GPTunneL catalog — all with context up to 1M tokens:
- Claude Opus 4.7 — the battle-tested version for teams that pinned their pipelines to it;
- Claude Opus 4.8 — the previous flagship, still an excellent choice;
- Claude Opus 5 — the current top of the line.
Anthropic keeps retiring older versions: Opus 4.1 was switched off back on August 5. If you work through GPTunneL, you don't need to track this — the API automatically swaps a retired model for the current one, and your integrations keep working without changes.
Claude Opus vs Sonnet: what's the difference
The most common question about the Claude lineup. The logic is simple:
- Sonnet is the workhorse. Claude Sonnet 5 and Sonnet 4.6 are noticeably cheaper per token and respond faster. For everyday writing, routine code, and typical tasks they're more than enough.
- Opus is the heavy artillery. It reasons deeper, holds long multi-step tasks more reliably, and loses the thread less often in a huge context. You pay more — and get quality where mistakes are expensive.
A practical rule: start with Sonnet and switch to Opus 5 when the answers stop satisfying you — in GPTunneL both models live in the same chat, so there's no need to move your prompt anywhere.
When to pick Opus 5
- Large codebases — refactoring, bug hunting, reviews: a million tokens of context fits the whole project.
- Agentic tasks — multi-step scenarios where the model plans, calls tools, and carries the work through on its own.
- Long documents — contracts, reports, research: analysis and cross-checking without slicing into chunks.
- Complex reasoning — math, strategy, analytics, where the quality of every step matters.
Where Opus 5 came from: the Honeycomb story
The official release was preceded by a classic wave of leaks: an experimental Honeycomb EAP model briefly surfaced in Cursor, users spotted the claude-opus-5 identifier in Google Vertex AI, and the codename Honeycomb was all over the community. The predictions came true almost word for word — both the 1M-token context and the stronger reasoning mode made it to release.
Where to try Claude Opus 5
- The official Anthropic site — the claude.ai web app with Pro and Max subscription plans.
- You can't download the model — Claude weights are closed and unpublished; Opus 5 can't run locally, only through cloud services.
- In GPTunneL — open Claude Opus 5 and compare it with Fable 5, GPT, and Gemini in one chat. Local payment methods supported, no subscription required.
How much Claude Opus 5 costs
In GPTunneL the model is billed per token: top up your balance and pay only for what you actually use — no subscription, no expiring quotas. Current input and output token prices are in the model card next to this article and on the pricing page, where you can also estimate the cost of your workload.
Claude Opus 5 FAQ
Is Claude Opus 5 free? No: on claude.ai the model requires a subscription, and the API is paid. In GPTunneL you pay per token with no mandatory subscription.
How is GPTunneL access different from an Anthropic subscription? Pro/Max is a fixed monthly fee with message limits. GPTunneL has no subscription: one balance for all models, pay-per-token billing, and GPT, Gemini, and the rest of the catalog sit right next to Opus 5 in the same chat.
Claude Opus or Sonnet — which is better? For everyday tasks — Sonnet: faster and cheaper. For complex code, long documents, and agentic workflows — Opus 5. The easiest way to decide is to compare both on your own prompt in one GPTunneL chat.
How is Opus 5 different from Fable 5? Fable 5 is Anthropic's new Mythos-class model, a tier above Opus: deeper reasoning but pricier tokens. Opus 5 is the flagship of the main lineup: the same up-to-1M context but noticeably cheaper, which is more than enough for most tasks.
Can I run Opus 5 locally? No. The model weights are closed and can't be downloaded — it's cloud-only: claude.ai, the Anthropic API, or GPTunneL.
Try it yourself
The best way to see what changed in Opus 5 is to run your own tasks through it: open Claude Opus 5 in GPTunneL and compare its answers with Opus 4.8 and Fable 5 on the same prompt. No subscriptions — pay only for what you use.