Claude Opus 5 Is Here: Near-Fable-5 Capability at Half the Cost

TL;DR: Claude Opus 5 ships today — near-Fable-5 performance at half the cost, same price as Opus 4.8, model ID claude-opus-5, 1M token context, effort slider, and 4x better code verification.

Anthropic released Claude Opus 5 on July 24, 2026. It's the new default on Claude Max and the strongest model on Claude Pro. The one-sentence case for upgrading: you get significantly better agentic coding, computer use, and long-horizon knowledge work at exactly what you were already paying.

What changed vs Opus 4.8

	Opus 4.8	Opus 5
Context window	200K tokens	1M tokens
Coding reliability	baseline	4× fewer unremarked code flaws
Effort slider	no	yes (low / medium / high)
Price	$5/$25/M tokens	$5/$25/M tokens (same)
Default on Max	yes	yes

Opus 5 is state-of-the-art on Anthropic's Frontier-Bench and GDPval-AA evals. Fable 5 remains ahead on cybersecurity-specific tasks.

API migration — one line

# Before
model = "claude-opus-4-8"

# After
model = "claude-opus-5"

No other changes required. Context window, pricing, and tool-use API are unchanged.

The effort slider

Opus 5 adds a three-level effort control — low, medium, high — accessible from the Claude.ai UI and through the API effort parameter. Use "low" for fast summarization or classification tasks where deep reasoning isn't needed; save "high" for multi-step planning or complex debugging. This replaces the separate Fast-mode approach (Opus 4.7 fast mode was deprecated today; migrate to Opus 4.8 or skip ahead to Opus 5).

When to use which model

Task	Model	Price/M tokens
Day-to-day coding, PR review, Q&A	Sonnet 5	$3 / $15
Complex agentic tasks, long-horizon work, knowledge Q&A	Opus 5	$5 / $25
Frontier cybersecurity, hardest research	Fable 5	$10 / $50

For most Claude Code sessions and agent workflows, Opus 5 is now the obvious default: it closes most of the gap with Fable 5 at half the API price, and the 1M token context window removes nearly all forced-summarization workarounds.

Sources: Introducing Claude Opus 5 — Anthropic · Claude Opus 5 on AWS — AWS Machine Learning Blog · VentureBeat · Bloomberg