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
Claude Sonnet 5.5
Claude Sonnet 5.5 is a mid-tier model from Anthropic, released on September 28, 2026 and available through the API as anthropic/claude-sonnet-5-5. It accepts text, image, and PDF input, with a 1M token context window and up to 128k output tokens. Pricing is $2 per million input tokens and $10 per million output tokens, the same as Claude Sonnet 5. Anthropic says it generates output more than 30% faster than Sonnet 5 and can cut the cost of a task by up to 30%, because it uses fewer tokens and fewer tool calls. Anthropic reports 70.6% on Terminal-Bench 4.0 (Sonnet 5: 10.3%) and 80.1% on OSWorld 2.1 (Sonnet 5: 57.0%). It is aimed at well-scoped everyday tasks, bug fixing, agentic coding, and producing documents, slides, and spreadsheets.
ChatClaude Opus 5.5
Claude Opus 5.5 is Anthropic's newest flagship model, released September 22, 2026 as the successor to Claude Opus 5. Anthropic positions it for agentic coding and long-running autonomous work. Reported benchmark scores include 66.4% on Terminal-Bench 4.0 (up from 52.3% for Opus 5), 54.4% on FrontierCode, 40% on AutomationBench (up from 26.9%), 81.8% on the OSWorld 2.0 computer-use benchmark, and 67.7% on Humanity's Last Exam with tools. It runs about 30% faster than Opus 5 and costs roughly 40% less on typical workloads, at $4 per million input tokens and $20 per million output tokens, a 1M-token context window, and 128K max output tokens. That combination of long-horizon coding performance, multimodal input (text, image, PDF), tool calling, and lower cost makes it a fit for developers building coding agents, codebase-wide migrations, and research or analysis pipelines through the API.
ChatClaude Fable 5.1
Claude Fable 5.1 is Anthropic's successor to Claude Fable 5, released September 1, 2026, about three months after Fable 5. Anthropic also released a companion model, Claude Mythos 5.1, available only through trusted access programs; both share the same underlying model with different safety safeguards. On SWE-bench Pro it scores 81.2%, ahead of Fable 5's 80% and Mythos 5's 80.3%. On Terminal-Bench-Science, a scientific-research agentic benchmark, it reaches 52.6%, more than double Fable 5's 24.7% and ahead of GPT-5.6 Sol's 22.4%. On Terminal-Bench 4.0 for agentic coding it scores 55.8%, versus 42.0% for Fable 5 and 37.3% for GPT-5.6 Sol. Priced at $10/$50 per million input/output tokens, unchanged from Fable 5, with cache reads cut 75% to $0.25 per million tokens. It offers a 1,000,000-token context window, 128,000-token max output, and tool calling. It fits developers running long-horizon agentic coding and research pipelines who want Fable-tier reasoning at lower cost.
Frequently Asked Questions
Claude Opus 4.6 Fast is no longer available through Puter.js. Explore other AI models for alternatives.
| 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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