GPT-5.5 Instant vs. Grok 4.3: Who Is the Current King of Value?
In May 2026, OpenAI released GPT-5.5 Instant as the default model for ChatGPT, while xAI launched Grok 4.3 to disrupt the market with aggressively low pricing. This article provides an in-depth comparison across four dimensions—performance benchmarks, pricing strategy, Agent capabilities, and security—to help you determine which model best fits your use case.