Claude Opus 5: everything you need to know

Short summary

Claude Opus 5 launched on July 24, 2026, priced at $5/$25 per million input/output tokens — half of Fable 5's cost — with a 1M token context window, 128K max output, and thinking enabled by default across five effort levels. Benchmarks show it matches or exceeds Fable 5 on CursorBench 3.2, OSWorld 2.0, Frontier-Bench, and ARC-AGI 3 while costing significantly less. Key migration concern: raise max_tokens to accommodate automatic thinking budget, and avoid disabling thinking at xhigh/max effort to prevent malformed tool calls.

• •Opus 5 ships at $5/$25 per M tokens, half of Fable 5, with 1M context and 128K output
• •Thinking is now on by default with five effort levels; disabling at xhigh/max returns 400
• •Beats or matches Fable 5 on most benchmarks at half the cost; lags on exploit development

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