Claude Opus 4
Anthropic's mid-2025 flagship, the model that established Claude's lead on coding agents and SWE-bench.
Updated
Quick facts
- Released
- May 2025
- Context
- 200K tokens
- Output / 1M
- $75.00 / 1M tokens
- License
- Proprietary
About Claude Opus 4
Opus 4 was the model that put Claude decisively in front for autonomous coding. SWE-bench Verified scores at launch led the field by a meaningful margin, and Cursor / Cline switched their defaults to it within weeks. It remains widely deployed even as 4.5 and 4.7 ship, mostly because of stability, production teams don't always rush every refresh.
Benchmarks
Published scores from Anthropic's model card or independent leaderboards. We do not publish numbers we cannot source, see methodology.
- HumanEval95.0
- SWE-bench Verified72.5
Capabilities
Strengths
- Set the SWE-bench bar at launch
- Excellent for writing and code
- Strong long-context handling
Tracked weaknesses
- Premium pricing
- Superseded by 4.5/4.7 for new builds
Pricing
Per-million-token rates as published by Anthropic.
| Tier | Price | Notes |
|---|---|---|
| Input | $15.00 / 1M tokens | Tokens you send to the model |
| Output | $75.00 / 1M tokens | Tokens the model generates |
| Context | 200K tokens | Max combined input + output |
Call Claude Opus 4 from your code
Drop-in snippet for the Anthropic SDK. Set your API key in the environment and run.
import Anthropic from "@anthropic-ai/sdk";
const client = new Anthropic({
apiKey: process.env.ANTHROPIC_API_KEY,
});
const message = await client.messages.create({
model: "claude-opus-4",
max_tokens: 1024,
messages: [
{ role: "user", content: "What's the time complexity of quicksort?" },
],
});
console.log(message.content);Compare Claude Opus 4 with…
Frequently asked
How much does Claude Opus 4 cost per million tokens?
Claude Opus 4 is priced at $15.00 / 1M tokens for input tokens and $75.00 / 1M tokens for output tokens via the official Anthropic API at the time of writing.What is Claude Opus 4's context window?
Claude Opus 4 supports a context window of 200K tokens.Is Claude Opus 4 open source?
No. Claude Opus 4 is a closed-weight model, you can use it via Anthropic's API but the model weights are not publicly downloadable.When was Claude Opus 4 released?
Claude Opus 4 was released on May 22, 2025 by Anthropic.What is Claude Opus 4's knowledge cutoff?
Claude Opus 4's training data has a knowledge cutoff of Mar 2025. For information after that date you'll need a tool-use or web-search wrapper.
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