How much does the Claude Opus 4.8 API cost?

Claude Opus 4.8 costs $5 per million input tokens and $25 per million output tokens, with cached input at $0.5 per million. A workload of 10M input and 1.5M output tokens per month costs about $87.50.

What is the context window of Claude Opus 4.8?

Claude Opus 4.8 supports a context window of 1,000,000 tokens (1M), with up to 64K output tokens per response.

Is Claude Opus 4.8 open source?

No — Claude Opus 4.8 is a proprietary model available through Anthropic's API and partner platforms.

What are the best alternatives to Claude Opus 4.8?

The closest alternatives by overall capability are Qwen3-Max, GPT-5.5, Gemini 3 Pro, Gemini 2.5 Pro. See the comparison pages for detailed head-to-head breakdowns.

Claude Opus 4.8

Name: Claude Opus 4.8
Price: 5 USD
Author: Anthropic

Anthropic·May 2026reasoningproprietary

Claude Opus 4.8 (May 2026) is the strongest model in the Claude 4.x line. It introduced adaptive thinking — the model decides how much reasoning each task deserves — plus four effort levels and a Fast Mode at 2x price for premium-speed inference. With 88.6% on SWE-bench Verified, leadership on Terminal-Bench 2.0 and a 1M-token context window at standard pricing, it is the model to beat for serious coding agents. Pricing stayed at $5/$25 per million tokens, undercutting GPT-5.5 on output cost.

Benchmark results

Where it shines

Top-tier agentic coding and terminal operation
Adaptive thinking with low/high/xhigh/max effort controls
1M context window at standard pricing
Cheaper output tokens than its OpenAI flagship rival

Alternatives to Claude Opus 4.8

Qwen3-Max

Alibaba's trillion-parameter API flagship — frontier-adjacent quality with strong agentic tool use at mid-tier prices.

GPT-5.5

OpenAI's flagship reasoning model with a 1M-token context window, built for hard coding, science and long-horizon agentic work.

Gemini 3 Pro

Google's November 2025 frontier breakout — 91.9% GPQA Diamond and 37.5% HLE made it the reasoning leader of its generation.

Gemini 2.5 Pro

Google's 2025 workhorse flagship — first mainstream thinking model with a 1M context, still widely deployed.

Frequently asked questions

How much does the Claude Opus 4.8 API cost?: Claude Opus 4.8 costs $5 per million input tokens and $25 per million output tokens, with cached input at $0.5 per million. A workload of 10M input and 1.5M output tokens per month costs about $87.50.
What is the context window of Claude Opus 4.8?: Claude Opus 4.8 supports a context window of 1,000,000 tokens (1M), with up to 64K output tokens per response.
Is Claude Opus 4.8 open source?: No — Claude Opus 4.8 is a proprietary model available through Anthropic's API and partner platforms.
What are the best alternatives to Claude Opus 4.8?: The closest alternatives by overall capability are Qwen3-Max, GPT-5.5, Gemini 3 Pro, Gemini 2.5 Pro. See the comparison pages for detailed head-to-head breakdowns.