Claude Opus 5.5 Launches at $4 and $20 per Million Tokens, 20% Below Opus 5

Anthropic released Claude Opus 5.5 on September 22, 2026, and cut the price of its Opus tier for the first time. The model costs $4 per million input tokens and $20 per million output tokens, down from $5 and $25 for Opus 5. It's available in the Claude API as claude-opus-5-5 and through the major cloud platforms.

The new rates

• Standard: $4 input and $20 output per million tokens (Opus 5: $5 and $25).
• Cache reads: $0.20 per million tokens, 5% of the input price and 60% below Opus 5's $0.50.
• Batch API: half price, $2 input and $10 output.
• Fast mode (up to 2.5 times faster): $8 input and $40 output.
• US-only inference: 1.1 times the standard rates.
• Context window: 1 million tokens, at no extra charge.

What it means for a real bill

The per-token cut is 20% on any workload. For an app sending 5,000 input tokens and getting 1,000 output tokens per request, 10,000 times a month:

The same traffic on Opus 5 costs $500 a month. Anthropic says typical workloads run about 40% cheaper than on Opus 5, because Opus 5.5 also uses fewer output tokens per task. That larger figure is Anthropic's own estimate; your saving depends on how long your model's answers are and how much of your input is cached.

Fable 5.1 cache reads also fell

Earlier in September, Claude Fable 5.1 launched at the same $10 input and $50 output as Fable 5, but with cache reads cut from $1.00 to $0.25 per million tokens. Workloads that resend a long system prompt or document benefit most.

Tip: Thinking tokens are billed as output. Before switching models, replay a sample of real requests at the effort level you'll use and compare the full cost per request, not just the rate card.