GPT-4.1: Cheaper, Smaller—and Smarter?

Just when you thought the versioning couldn’t get weirder, OpenAI dropped GPT-4.1 after GPT-4.5. Either OpenAI skipped the version control class, or GPT-4.5 was the flashy prototype (while GPT-4.1 is the stable release that actually shows up to work on time).

Naming quirks aside, GPT-4.1 is a major milestone—not just because it’s smarter and more efficient, but because it reflects a deeper shift in how AI models are being built. That is: OpenAI managed to shrink the architecture (compared to GPT-4.5) while improving its capabilities.

Launched on April 14, 2025, GPT-4.1 introduces a new family of models built for real-world applications, especially for coding, reasoning, and multimodal tasks.

GPT-4.1 brings notable improvements over previous versions, including:

• Expanded context window (up to 1 million tokens)

• Real-world coding workflows

• Structured outputs and instruction following

• Cost-efficiency with variant flexibility (base, mini, nano)

Whether you're building AI assistants, scaling high-volume pipelines, or debugging massive codebases, we’ll break down what you need to know, so you can decide if this new frontrunner belongs in your stack.

We’ll cover:

• What’s new in GPT-4.1 (and how it compares to GPT-4 and GPT-4.5)

• How to choose between the base, mini, and nano variants

• Benchmark results across coding, instruction following, and long-context tasks

• A head-to-head comparison with Google’s Gemini 2.5 and Anthropic’s Claude 3.7

Let’s dive into what makes GPT-4.1 a meaningful leap—not just a version bump.