GPT-5.2 is definitely not just a regular iteration of 5.1—OpenAI clearly went all out this time. - Major knowledge base update: GPT-5.2’s world knowledge cutoff date has been updated to August 31, 2025, while GPT-5.1 was only up to September 30, 2024. - Significant price hike: The output token price for GPT-5.2 has increased by 40% across the board compared to its predecessor. The flagship gpt-5.2-pro now costs $168 per million tokens. - Benchmark dominance: GPT-5.2 showcased absolute superiority in the most intellectually challenging benchmarks. For example, in the high-difficulty ARC-AGI 2 test, its score skyrocketed from 17.6% in the previous generation to 52.9%. In comparison, Gemini and Claude series haven’t broken the 40% mark yet. - Post-training tech upgrades: According to @SemiAnalysis_, GPT-5.2 adopted more aggressive post-training strategies. In addition to likely introducing mid-training to refresh knowledge, it also extensively applied reinforcement learning (RL). This shift in technical approach significantly enhances the model’s logical depth in long-context processing and programming. - Real-world user experience: Early tester @mattshumer_ (testing since 11/25) noted massive improvements in instruction following, code generation, and complex task breakdown. But there’s a clear trade-off: the thinking speed has slowed down.