Claude Opus 4.5: The World's Most Advanced AI Model

The Announcement That Redefines AI

November 24, 2025 — Anthropic unveils Claude Opus 4.5, its most advanced model to date. Presented as “the best model in the world for coding, agents, and computer use,” Opus 4.5 marks a significant milestone in the evolution of AI systems.

Introducing Claude Opus 4.5: the best model in the world for coding, agents, and computer use. Opus 4.5 is a step forward in what AI systems can do, and a preview of larger changes to how work gets done. — @claudeai on X

🔗 Official announcement on anthropic.com

Why Opus 4.5 Changes the Game

Claude Opus 4.5 is not just an incremental update. This model represents a qualitative leap in several key areas:

Intelligent Reasoning

Opus 4.5 excels in managing ambiguity and trade-offs. The model demonstrates an increased ability to navigate complex situations where multiple valid approaches exist, choosing the most appropriate one for the context.

Extended Context Management

Thanks to automatic summarization, Opus 4.5 eliminates conversation length limits. The model can maintain context over prolonged work sessions without performance degradation.

Multi-Agent Coordination

One of the major advances concerns the ability to orchestrate multi-agent systems. Opus 4.5 can coordinate multiple autonomous processes working in parallel on complex tasks.

Advanced Computer Use

The model can now directly manipulate:

Spreadsheets — Analysis and modification of Excel/Sheets data
Presentations — Creation and editing of slides
Browser — Automation of complex web tasks
Desktop Applications — Interaction with native software

Benchmarks: The Numbers Speak

Software Engineering Performance

Benchmark	Opus 4.5	Improvement
SWE-bench Verified	State-of-the-art	Absolute leader
SWE-bench Multilingual	7/8 languages	Best on 7 languages
Aider Polyglot	+10.6%	vs Sonnet 4.5
Vending-Bench	+29%	vs Sonnet 4.5
Terminal Bench	+15%	vs Sonnet 4.5
BrowseComp-Plus	Significant gains	Agentic research

A Highlight

During an internal Anthropic engineering exam with a 2-hour limit, Opus 4.5 achieved a score higher than all human candidates. A first that illustrates the level reached by this model.

Revolutionary Token Efficiency

One of the most impressive aspects of Opus 4.5 is its token efficiency. The model produces equivalent or superior results with significantly fewer tokens:

Effort Level	Performance	Token Reduction
Medium Effort	Equal to Sonnet 4.5	-76% tokens
Maximum Effort	+4.3% vs Sonnet 4.5	-48% tokens
Long Tasks	Maintained	-65% tokens

What This Means Concretely

Reduced Costs — Fewer tokens = lighter API bill
Faster Responses — Less generation = reduced latency
More Efficient Reasoning — Less backtracking and redundant exploration

Pricing and Availability

API Access

Parameter	Value
Model ID	`claude-opus-4-5-20251101`
Input Price	$5 / million tokens
Output Price	$25 / million tokens
Context Window	200K tokens
Thinking Budget	64K tokens

Available Platforms

Anthropic API — Direct access
AWS Bedrock — Amazon cloud integration
Google Vertex AI — Google cloud integration
Claude Applications — claude.ai, desktop, mobile

What Companies Are Saying

Feedback from early adopters is unanimous:

GitHub Copilot

The model outperforms our internal coding benchmarks while cutting token usage in half. — Mario Rodriguez, Chief Product Officer

Windsurf AI

Clear winner… best frontier task planning and tool calling. — Jeff Wang, CEO

Replit

Using fewer tokens to solve the same problems. — Michele Catasta, President

Warp

15% improvement over Sonnet 4.5 on Terminal Bench for autonomous tasks. — Zach Lloyd, Founder

Cursor

Notable improvement with improved pricing and intelligence. — Michael Truell, CEO

Product Improvements

Opus 4.5 comes with several new features in the Claude ecosystem:

Claude Code — Enhanced Plan Mode

Clarification questions before execution
User-editable plan.md files
Better coordination of multi-file edits

Claude Desktop

Parallel local and remote sessions
Integrated screenshot capture
Context sharing by clicking on windows
Voice command (Caps Lock to speak)

Claude for Chrome (Available for All Paid Plans)

Initially in beta, Claude for Chrome is now available for all paid plans (Pro, Team, Enterprise) since December 18, 2025. The extension allows Claude to interact directly in the browser:

Autonomous Navigation — Browse sites, click, fill forms
Multi-tabs — Work on multiple tabs simultaneously
Automation — Extract metrics, manage cloud files, prepare calendar
Integrations — Google Drive, Salesforce, Gmail, CRM
Scheduled Workflows — Daily or weekly automations
Security — Review of sensitive actions before execution

🔗 Learn more about Claude for Chrome

Other Integrations

Claude for Excel — Beta extended to Max, Team, and Enterprise
Extended Conversations — No more length limits thanks to auto-summarization

Safety and Alignment

Anthropic presents Opus 4.5 as its “most robustly aligned model to date”:

Resistance to Attacks

Prompt Injection — Harder to trick than any competitor model
Misuse Categories — Reduced “concerning behavior” scores

System Card

The safety document details measures taken to ensure reliable and predictable behavior, even in complex edge-case scenarios.

Technical Specifications

Specification	Value
Context Window	200K tokens (default)
Thinking Budget	64K tokens (interleaved)
Evaluation Methodology	Average of 5 independent trials
Effort Parameter	Configurable (speed vs capability)
Sampling	Standard temperature and top-p

Architectural Advantages

Efficient multi-step reasoning reducing backtracking
Optimized context compaction
Memory tools for sustained reasoning over long sessions

Conclusion

Claude Opus 4.5 represents more than a model update — it is a demonstration of what AI can accomplish when efficiency and capability advance together.

For developers, the implications are clear:

Better Performance on coding and automation tasks
Reduced Costs thanks to token efficiency
New Possibilities with computer use and multi-agent coordination