Anthropic: Claude Opus 4.8
anthropic/claude-opus-4-8
Try Claude Opus 4.8 for free in your browser, and add it to your app for free with Puter.js AI API.
Try it free Add to your app// npm install @heyputer/puter.js
import { puter } from '@heyputer/puter.js';
puter.ai.chat("Explain quantum computing in simple terms", {
model: "anthropic/claude-opus-4-8"
}).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", {
model: "anthropic/claude-opus-4-8"
}).then(response => {
document.body.innerHTML = response.message.content;
});
</script>
</body>
</html>
Model Card
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.
Context Window 1M
tokens
Max Output 128K
tokens
Input Cost $5
per million tokens
Output Cost $25
per million tokens
Input text, image, pdf
modalities
Tool Use Yes
Knowledge Cutoff Jan 2026
Release Date May 28, 2026
Try Claude Opus 4.8 for free
Try Claude Opus 4.8 instantly in your browser.
This playground uses the Puter.js AI API — no API keys or setup required.
Benchmarks
How Claude Opus 4.8 performs on standard evaluations.
| Benchmark | Score |
|---|---|
| GPQA Diamond Graduate-level science Q&A | 92.0% |
| Humanity's Last Exam Cross-domain reasoning | 48.7% |
| SciCode Scientific programming | 54.4% |
| IFBench Instruction following | 62.2% |
| LCR Long-context reasoning | 77.7% |
| Terminal-Bench Hard Agentic terminal tasks | 58.3% |
| τ²-Bench Tool use / agents | 94.4% |
Scores sourced from Artificial Analysis.
Find other Anthropic models →
Claude Haiku 5.5
Claude Haiku 5.5 is the small, low-cost model in Anthropic's 5.5 family, released on October 7, 2026 and available through the API as anthropic/claude-haiku-5-5. It has a 1M token context window and up to 128k output tokens. Pricing is $0.10 per million input tokens and $0.50 per million output tokens for requests under 100,000 tokens, down from $1 and $5 for Haiku 4.5, and $0.50 and $2.50 above that. Effort levels range from low to max, with medium as the default. Anthropic reports 72.4% on OSWorld 2.1 (offline subset, Haiku 4.5: 15.7%) and 39.2% on Terminal-Bench 4.0 at maximum effort (Haiku 4.5: 0.0%). On the same tests GPT-6 Luna scores 48.9% and 16.4%. It is aimed at summarizing documents, classifying information, querying databases, and handling subtasks for larger agents. Anthropic recommends Opus and Sonnet for demanding coding work.
ChatClaude 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.
Frequently Asked Questions
You can access Claude Opus 4.8 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.
Claude Opus 4.8 is free to try with a Puter account. Every account includes a free AI allowance, and you can chat with it in the playground on this page. You can upgrade your account anytime for a larger allowance.
Claude Opus 4.8 is free to integrate using the Puter.js AI API. With the User-Pays Model, you can add AI to your app for $0, since users cover their own AI usage through their Puter account.
| Price per 1M tokens | |
|---|---|
| Input | $5 |
| Output | $25 |
Claude Opus 4.8 was created by Anthropic and released on May 28, 2026.
Claude Opus 4.8 supports a context window of 1M tokens. For reference, that is roughly equivalent to 2,000 pages of text.
Claude Opus 4.8 can generate up to 128K tokens in a single response.
Claude Opus 4.8 has a knowledge cutoff date of Jan 2026. This means the model was trained on data available up to that date.
Claude Opus 4.8 accepts the following input types: text, image, pdf. It produces: text.
Yes, Claude Opus 4.8 supports tool use (function calling), allowing it to interact with external tools, APIs, and data sources as part of its response flow.
Claude Opus 4.8 scores 41.8 on the Artificial Analysis Intelligence Index, outperforming 92% of tracked models. On coding, it scores 74.3 (outperforms 87% of models).
Yes — the Claude Opus 4.8 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.
Add Claude Opus 4.8 to your app for free
Developers can integrate Claude Opus 4.8 for free using the Puter.js AI API.
With the User-Pays Model, each user covers their own AI usage instead of the developer.