Claude 4.5 Opus vs Claude 3.5 Sonnet

1. Maximum capability with more practical pricing

• Anthropic introduced Opus 4.5 as its most intelligent model, combining maximum capability with practical performance.
• It was positioned as the best model in the world for coding, agents, and computer use at launch, with pricing reduced to $5/M input and $25/M output.

2. Step-change gains for coding and advanced agent work

• Anthropic describes Opus 4.5 as state-of-the-art on real-world software engineering tests.
• It also improved everyday knowledge-work tasks like deep research, slides, and spreadsheets while staying strong on long-horizon agent workflows.

3. Better control over reasoning depth

• Opus 4.5 introduced the effort parameter, letting developers trade off response thoroughness against token efficiency.
• This made it easier to use one flagship model across both high-depth analysis and more cost-sensitive production workloads.

4. Stronger computer use and continuity

• Added enhanced computer use with a zoom action for inspecting detailed screen regions.
• Preserves prior thinking blocks across turns, helping the model maintain reasoning continuity in extended multi-step tasks.

1. Intelligence & Reasoning

• Outperforms previous Claude models and competitor LLMs across major benchmarks.
• Excels in graduate-level reasoning (GPQA), knowledge tasks (MMLU), and coding (HumanEval).
• Handles nuance, humor, and complex instructions with human-like clarity.

2. Speed & Efficiency

• Runs 2x faster than Claude 3 Opus, making it ideal for real-time and high-volume workflows.
• Cost-effective pricing: $3/M input tokens and $15/M output tokens.
• Supports a 200K token context window, enabling rich, long-form reasoning.

3. Coding Capabilities

• Solves significantly more coding and bug-fix tasks (64% vs Opus's 38% in internal evaluations).
• Can autonomously write, edit, and execute code when tool use is enabled.
• Strong at translating and modernizing legacy codebases.

4. Vision Strength

• Best vision model in the Claude family, surpassing Opus on vision benchmarks.
• Excellent at interpreting charts, graphs, and imperfect images.
• Reliable text extraction from low-quality visuals for retail, logistics, finance, etc.

5. Agentic Workflows

• Highly capable for multi-step task orchestration.
• Performs well as the engine for agents requiring reasoning, planning, and tool-calling abilities.

6. Content Quality

• Produces natural, relatable writing with improved tone, style, and context awareness.
• Strong at long-form content creation and editing.

7. Safety & Reliability

• Rated ASL-2, meeting Anthropic's safety standards.
• Undergoes extensive red-teaming and external evaluation (UK AISI & US AISI).
• Not trained on user data without explicit permission.