Anthropic Releases Claude Opus 4.8 — Everything You Need to Know

Anthropic has shipped Claude Opus 4.8, the latest iteration of its flagship model and the new default in Claude Code. The update is an incremental but meaningful step over Opus 4.7 — sharper agentic coding, a faster output mode, and pricing that keeps it competitive with OpenAI's GPT-5.5 and Google's Gemini 3 Pro.

TL;DR: Opus 4.8 is the strongest model for long-horizon coding and agentic workflows right now. The headline feature is Fast mode — full Opus quality with noticeably quicker output — not a downgrade to a smaller model.

What's New in Claude Opus 4.8

Better Agentic Coding

The biggest gains are in multi-step, tool-using tasks. Opus 4.8 holds context across long agent runs more reliably, makes fewer wrong turns mid-task, and recovers better when a tool call fails. For developers running Claude Code on large codebases, that translates into fewer dead ends on complex refactors.

Fast Mode

Opus 4.8 introduces a Fast mode that delivers the same Opus-class reasoning with faster output. Importantly, it does not swap in a smaller model under the hood — you get full Opus quality, just quicker. It can be toggled in Claude Code with /fast and is available on Opus 4.8, 4.7, and 4.6.

Refreshed Model Lineup

Claude Opus 4.8 — frontier reasoning and the best choice for complex coding and agents.
Claude Sonnet 4.6 — balanced speed and capability for everyday work.
Claude Haiku 4.5 — fast and cheap for high-volume, lightweight tasks.

How It Compares

Opus 4.8 trades blows with GPT-5.5 and Gemini 3 Pro at the frontier. Anthropic continues to lead on coding and agentic reliability, while OpenAI and Google retain edges in some broad-knowledge and multimodal benchmarks.

Model	Best at	Context	Fast mode
Claude Opus 4.8	Coding, agents	200K+ tokens	Yes
GPT-5.5	General reasoning	256K tokens	No
Gemini 3 Pro	Multimodal, long context	1M tokens	No

Where to Use It

Opus 4.8 is available through the Claude apps, the Anthropic API (model ID claude-opus-4-8), and as the default in Claude Code across the CLI, desktop, web, and IDE extensions. If you're building AI applications, it's the model to default to for anything involving tool use or long-running tasks.

Bottom Line

Claude Opus 4.8 won't reshape the landscape on its own, but it widens Anthropic's lead in agentic coding and makes the everyday experience faster with Fast mode. If you live in Claude Code, the upgrade is a clear win. For a head-to-head on raw reasoning, see our GPT-5 vs Claude Opus comparison.

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