Claude Opus 4.5 vs GPT-5.2
A detailed breakdown of how Anthropic's latest flagship compares to OpenAI's GPT-5 series in reasoning, coding, and reliability.
The Verdict
"Opus 4.5 is the superior choice for deep, agentic work and complex coding."
The AI landscape has shifted dramatically in 2025. While OpenAI's GPT-5.2 offers an incredible streamlined experience, Claude Opus 4.5 has cemented itself as the tool for "deep work."
Here is why developers and power users are choosing Opus.
At a Glance
| Feature | Claude Opus 4.5 | GPT-5.2 |
|---|---|---|
| Primary Strength | Agentic Coding & Deep Reasoning | General Speed & Versatility |
| Context Window | 200k (High Fidelity) | 400k |
| Coding Score (SWE-bench) | 80.9% (Best in Class) | 80.0% |
| Unique Feature | Computer Use & Effort Control | Safe Completions & Thinking Mode |
| Cost | Premium (~$1.76/task) | Standard (~$1.25/task) |
The Opus Advantage: Agentic Capabilities
The single biggest differentiator for Claude Opus 4.5 is its Agentic Nature. It doesn't just answer questions; it performs tasks.
1. Computer Use
Opus 4.5 is the only model currently capable of reliably navigating computer interfaces. It can "see" your screen (via screenshots), move cursors, type text, and manipulate UI elements. This allows it to:
- Debug full-stack applications by navigating the localhost browser.
- Automate complex data entry workflows across multiple legacy apps.
- Perform end-to-end testing effectively.
2. The "Effort" Parameter
Opus 4.5 introduced a groundbreaking "Effort" parameter. You can signal to the model how hard it should think:
- High Effort: Opus explores multiple reasoning paths, self-corrects, and drafts comprehensive solutions (perfect for architecture).
- Low Effort: Fast, concise answers for quick clarifications.
Reasoning and Coding
While GPT-5.2 is a powerhouse, Opus 4.5 edges it out in nuance and reliability.
"In complex refactoring tasks involving thousands of lines of code, Opus 4.5 consistently maintained the logic without regression, whereas GPT-5.2 occasionally hallucinated variable names." — Senior Software Engineer @ TechCorp
The "Thinking Block"
Opus maintains a "thinking block" where it preserves its chain of thought across multi-turn conversations. This means if you are debugging a problem for an hour, Opus remembers the reasoning behind the first step, not just the text.
When to Choose GPT-5.2?
GPT-5.2 is an excellent model and dominates in:
- Daily Assistant Tasks: Drafting emails, quick summaries, and creative brainstorming.
- Cost Efficiency: For high-volume API calls where "good enough" is acceptable.
- Abstract Reasoning: It performs slightly better on abstract logic puzzles (ARC-AGI).
Verdict
If you need a chat bot, GPT-5 is fantastic.
But if you need a Digital Coworker to architect systems, write production code, and autonomously navigate your tools, Claude Opus 4.5 is the only choice.