What Is Claude 4?
Claude 4 is the latest AI model series released by Anthropic, featuring Claude Opus 4 and Claude Sonnet 4. Among them, Claude Opus 4 is currently one of the most powerful coding models in the world, excelling at complex programming tasks and long-running workflows such as code generation, optimization, and debugging. Meanwhile, Claude Sonnet 4 brings notable improvements in reasoning and programming accuracy, making it ideal for everyday use.
Both models offer fast response times and support deep thinking modes, with the ability to use tools in parallel—greatly enhancing their memory and contextual understanding. With features like tool-assisted extended reasoning and memory file management, Claude 4 significantly improves the practicality and efficiency of AI agents.
Key Features of Claude 4
Code Generation and Optimization
Claude Opus 4 leads industry benchmarks such as SWE-bench and Terminal-bench, generating clean, high-quality code with advanced reasoning.
Long-Running Task Handling
Claude Opus 4 can manage complex, multi-hour tasks without degradation in performance—outperforming other models in sustained workflows.
Code Editing and Debugging
Claude Sonnet 4 excels at editing and fixing code across multiple files, delivering accurate updates and contextual fixes.
Advanced Reasoning
Claude Opus 4 tackles problems that other models struggle with, making it ideal for scientific research, edge-case analysis, and logic-heavy tasks.
Multimodal Capabilities
Claude 4 supports text and image inputs and performs well across coding, reasoning, vision tasks, and AI agent operations.
Tool Use and Extended Thinking
The model can invoke tools like web search for expanded reasoning. It uses tools in parallel, optimizing response quality and task throughput.
File Access and Memory
When granted permission, Claude 4 can read local files, extract and retain key information, and improve task continuity and contextual memory.
Reduced Shortcut Behavior
Compared to Claude Sonnet 3.7, Claude 4 reduces shortcut-seeking behavior by 65%, leading to more trustworthy results.
Memory File System
Claude Opus 4 introduces “memory files” to store key context over time. For example, it can generate and retain a navigation guide while playing a Pokémon game.
Thought Summarization
Claude 4 includes a summarization feature that compresses lengthy internal thoughts, needing full output only about 5% of the time.
Benchmark Results
Claude Opus 4:
- SWE-bench: 72.5% – a significant lead over other models
- Terminal-bench: 43.2% – demonstrating superior command-line coding performance
Claude Sonnet 4:
- SWE-bench: 72.7% – outstanding performance in coding efficiency for a general-use model
Pricing
- Claude Opus 4: $15 per million input tokens, $75 per million output tokens
- Claude Sonnet 4: $3 per million input tokens, $15 per million output tokens
- Subscription Plans: Claude Opus 4 and Sonnet 4 are available under Pro, Max, Team, and Enterprise plans. Claude Sonnet 4 is also accessible to free-tier users with limitations.
Real-World Applications
Programming Assistant
Generate and refine code with speed and accuracy, helping developers focus on logic instead of syntax.
AI Agents
Handle multi-step tasks, call external tools, and maintain context for intelligent agent flows.
Software Development
Provide code suggestions in IDEs, automate code reviews, and improve software quality.
Data Analysis
Generate code for data visualization and execute complex data transformation pipelines.
Natural Language Tasks
Produce high-quality, context-aware text and support multilingual translation.
Claude 4 marks a major step forward in making AI more useful, reliable, and developer-friendly. Whether you’re building next-generation AI agents or just looking to supercharge your coding workflows, Claude 4 offers one of the most capable toolsets available today.
