OpenAI just dropped GPT-5.4 with a 1-million-token context window and autonomous multi-step workflows. Anthropic countered with Claude Opus 4, featuring extended thinking and deep analysis. The question everyone is asking: which one is actually better for your work in 2026?
We tested both models head-to-head across five categories that matter most to real users: writing quality, code generation, reasoning accuracy, context handling, and daily productivity tasks.
Context Window: GPT-5.4's Headline Feature
GPT-5.4's 1-million-token context window is genuinely impressive. In our tests, it successfully summarized a 400-page legal document without losing critical details in the middle sections — a problem that plagued earlier models. Claude's context window, while smaller, compensates with superior attention to detail within its range. For most users who aren't processing book-length documents, the practical difference is minimal.
Code Generation: Closer Than You Think
On the OSWorld-V benchmark, GPT-5.4 scored 75%, slightly above the human baseline of 72.4%. Claude continues to excel at complex refactoring tasks and understanding entire codebases. In our hands-on testing with a real React application, GPT-5.4 was faster at generating boilerplate, while Claude produced fewer bugs in logic-heavy components.
| Capability | GPT-5.4 | Claude Opus 4 |
|---|---|---|
| Context Window | 1M tokens | 200K tokens |
| Coding (SWE-bench) | 72.1% | 74.3% |
| Reasoning (GPQA) | 68.4% | 71.2% |
| Writing Quality | Good | Excellent |
| Speed | Fast | Moderate |
| Price | $20/mo | $20/mo |
Autonomous Workflows: The Real Battleground
GPT-5.4's ability to autonomously execute multi-step workflows across software environments is the most significant new capability. You can ask it to research a topic, compile findings, format a report, and send it — all in one chain. Claude's approach is different: its extended thinking mode shows you the reasoning process, giving you more control and transparency over complex tasks.
Writing and Analysis: Claude Still Leads
For nuanced writing, editorial work, and long-form analysis, Claude remains the stronger choice. GPT-5.4 has closed the gap significantly, but Claude's outputs still read more naturally and require less editing. This matters if you're producing client-facing content or detailed reports.
Daily Productivity: GPT-5.4 Wins on Breadth
GPT-5.4's integration with the broader OpenAI ecosystem (DALL-E, Sora, web browsing, code interpreter) gives it an edge for users who need one tool to do everything. If you regularly switch between text, image, and code tasks within a single workflow, GPT-5.4 is more convenient.
Our Verdict
Read our full reviews: ChatGPT Plus Review | Claude Pro Review | Head-to-Head Comparison