Introducing GPT-4.1 in the API

OpenAI released GPT-4.1, GPT-4.1 mini, and GPT-4.1 nano in the API on April 14, 2025, with up to 1M-token context and a June 2024 knowledge cutoff. GPT-4.1 scored 54.6% on SWE-bench Verified, up 21.4 points over GPT-4o; GPT-4.1 mini cuts cost by 83% with nearly half the latency; GPT-4.5 Preview shuts down on July 14, 2025.

Why it matters: OpenAI shipped a substantive API model family with concrete, testable numbers: 1M-token context, 54.6% on SWE-bench Verified, 83% lower mini cost, and a GPT-4.5 Preview sunset date. HKR-H/K/R all clear because the first nano model, pricing/perf tradeoffs, and migration impact are