Anthropic: Claude Opus 4.6 Fast
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Claude Opus 4.6 Fast is a high-speed configuration of Anthropic's most intelligent model, delivering up to 2.5x faster output token generation with no reduction in quality or capabilities.
It runs the same Opus 4.6 model — state-of-the-art on benchmarks like Terminal-Bench 2.0 for agentic coding, Humanity's Last Exam for multidisciplinary reasoning, and GDPval-AA for professional knowledge work — but optimized for lower latency at premium pricing ($30/$150 per MTok). It supports the full 1M token context window and 128k max output tokens.
Fast mode is ideal for latency-sensitive, interactive workflows such as rapid iteration, live debugging, and real-time agentic tasks where waiting on responses breaks your flow. For cost-sensitive or batch workloads, standard Opus 4.6 offers the same intelligence at lower cost.
Context Window 1M
tokens
Max Output 128K
tokens
Input Cost $30
per million tokens
Output Cost $150
per million tokens
Release Date Apr 7, 2026
Code Example
Add AI to your app with the Puter.js AI API — no API keys or setup required.
// npm install @heyputer/puter.js
import { puter } from '@heyputer/puter.js';
puter.ai.chat("Explain quantum computing in simple terms").then(response => {
document.body.innerHTML = response.message.content;
});
<html>
<body>
<script src="https://js.puter.com/v2/"></script>
<script>
puter.ai.chat("Explain quantum computing in simple terms").then(response => {
document.body.innerHTML = response.message.content;
});
</script>
</body>
</html>
More AI Models From Anthropic
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Claude Sonnet 5 is Anthropic's newest Sonnet-tier model, released June 30, 2026 as the successor to Sonnet 4.6. Anthropic built it to be the most agentic Sonnet yet, with gains in planning, tool use, coding, and multi-step reasoning that bring it close to Opus 4.8 quality at a lower price. On SWE-bench Pro it scores 63.2%, up from Sonnet 4.6's 58.1% and ahead of GPT-5.5's 58.6%, though still behind Opus 4.8's 69.2%. On Terminal-Bench 2.1 it reaches 80.4% versus Sonnet 4.6's 67.0%, and on the OSWorld-Verified computer-use benchmark it posts 81.2% against Sonnet 4.6's 78.5%. It targets developers running agentic coding pipelines, automation workflows, and tool-heavy tasks who want most of Opus-tier capability without Opus pricing. Introductory pricing is $2/$10 per million input/output tokens through August 31, 2026, after which it reverts to the standard $3/$15 listed here.
ChatClaude Fable 5
Claude Fable 5 is Anthropic's most capable generally available model — a publicly released, safety-hardened version of its frontier Mythos-class system, launched June 2026. It is state-of-the-art on nearly every benchmark Anthropic tested, with its lead over prior Claude models growing the longer and more complex the task. It scores 80.3% on SWE-bench Pro, well ahead of Claude Opus 4.8 (69.2%) and GPT-5.5 (58.6%). During early testing, Stripe used it to run a codebase-wide migration in a day that would have taken a team over two months by hand. It's also Anthropic's new state-of-the-art for vision tasks and can work autonomously longer than any previous Claude model. Priced at $10/$50 per million input/output tokens — less than half the cost of Claude Mythos Preview — it targets developers building agentic coding pipelines, vision-heavy workloads, and long-horizon autonomous tasks. Queries on a small set of sensitive topics fall back to Opus 4.8 (on average under 5% of sessions).
ChatClaude Opus 4.8
Claude Opus 4.8 is Anthropic's latest flagship AI model, building on Opus 4.7 with improvements across coding, reasoning, and knowledge work — at the same price point. The model excels at complex, multi-step agentic workflows including coding, financial analysis, legal reasoning, and browser-based computer use. Early testers report it outperforms both prior Opus models and GPT-5.5 across several agentic benchmarks. Notably, it's around four times less likely than Opus 4.7 to let flaws in generated code pass without flagging them. Opus 4.8 supports configurable effort levels, letting developers trade quality against speed and token cost. A fast mode operates at 2.5× speed. Priced at $5/$25 per million input/output tokens, it targets teams running autonomous agents, analysis pipelines, and long-running async workflows where reliability and judgment are critical.
Frequently Asked Questions
You can access Claude Opus 4.6 Fast by Anthropic through Puter.js AI API. Include the library in your web app or Node.js project and start making calls with just a few lines of JavaScript — no backend and no configuration required. You can also use it with Python or cURL via Puter's OpenAI-compatible API.
Yes, it is free if you're using it through Puter.js. With the User-Pays Model, you can add Claude Opus 4.6 Fast to your app at no cost — your users pay for their own AI usage directly, making it completely free for you as a developer.
| Price per 1M tokens | |
|---|---|
| Input | $30 |
| Output | $150 |
Claude Opus 4.6 Fast was created by Anthropic and released on Apr 7, 2026.
Claude Opus 4.6 Fast supports a context window of 1M tokens. For reference, that is roughly equivalent to 2,000 pages of text.
Claude Opus 4.6 Fast can generate up to 128K tokens in a single response.
Yes — the Claude Opus 4.6 Fast API works with any JavaScript framework, Node.js, or plain HTML through Puter.js. Just include the library and start building. See the documentation for more details.
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