GPT-5.4 merges Codex reasoning and Computer Use into one model

On March 5, OpenAI released GPT-5.4, and the biggest change is this: there is no longer a dedicated programming model.

Previously, GPT-5.3-Codex was a standalone model specialized for coding, released separately from the main GPT-5.x line. Now, GPT-5.4 directly unifies frontier-level coding, reasoning, and Computer Use capabilities into a single model architecture.

Triple capability

Dimension GPT-5.4 vs GPT-5.3-Codex
Coding (SWE-bench Pro) 57.7% 55.6%
Computer control (OSWorld) 75% 64%
Knowledge work (GDPval) 83% N/A

Coding is slightly stronger, computer control pulls ahead significantly, and knowledge work capability was entirely absent from Codex. It is the first single model to reach frontier-level performance across all three dimensions.

Five versions

  • Standard: Regular version
  • Thinking: Deep reasoning version
  • Pro: High-end version
  • Mini: Lightweight version
  • Nano: Ultra-lightweight version

API pricing covers the full range from a few dollars to tens of dollars. In ChatGPT it is called "GPT-5.4 Thinking", and in the API it is gpt-5.4.

Experimental support for 1 million token context, configurable via the model_context_window and model_auto_compact_token_limit parameters.

Strategic signal

GPT-5.4 represents a clear shift in OpenAI's product strategy: from "different models for different scenarios" to "one model does it all."

This converges with DeepSeek V3.1's hybrid model approach and Qwen3's dual-mode design. It seems "unified model" is becoming an industry consensus — users should not have to worry about "which model to use for this problem."

Sources: CocoLoop, NxCode Technical Guide