GPT-5.1-Codex vs GPT-5.4
A side-by-side comparison of two multimodal models — real specs, pricing, strengths and weaknesses, and a clear verdict on which to choose. Kept current by our agents.
Quick verdict: which should you choose?
Choose GPT-5.1-Codex if you need
- ✓coding workflows that integrate visual context with code
- ✓fast output at 171.14 t/s and lower $10/1M pricing
- ✓400k context inputs without coherence loss in extended sessions
- ✓software development tasks where prompt engineering can be managed
Choose GPT-5.4 if you need
- ✓extremely large 1.05M context windows for document-level tasks
- ✓seamless integration across text, image, and file inputs
- ✓higher intelligence_index of 51.4 for complex multimodal reasoning
- ✓flexible workflows handling very large-scale text and file data
Verdict
GPT-5.4 leads with a higher intelligence_index (51.4 vs 34.7) and triple the context window, suiting document-scale multimodal work, while GPT-5.1-Codex wins on speed (171.14 t/s) and lower price ($10 vs $15 per 1M tokens) for coding-focused tasks. GPT-5.1-Codex is specialized for visual-code integration in software development; GPT-5.4 offers broader text-image-file flexibility but at higher cost and slower output.
GPT-5.1-Codex vs GPT-5.4: side by side
| Spec | GPT-5.1-Codex | GPT-5.4 | Winner |
|---|---|---|---|
| Intelligence | 34.7 | 51.4 | GPT-5.4 |
| Output speed | 171 t/s | 147 t/s | GPT-5.1-Codex |
| Output price | $10.00/1M | $15.00/1M | GPT-5.1-Codex |
| Context | 400K | 1050K | GPT-5.4 |
| Params | — | — | Tie |
| Provider | OpenAI | OpenAI | Tie |
Detailed analysis
Intelligence
Winner: GPT-5.4GPT-5.4 scores 51.4 on the intelligence_index compared to 34.7 for GPT-5.1-Codex. This gap favors GPT-5.4 for tasks requiring stronger overall reasoning. Both remain proprietary OpenAI models with similar prompt-engineering needs.
Speed and Pricing
Winner: GPT-5.1-CodexGPT-5.1-Codex delivers 171.14 tokens per second at $10 per million tokens. GPT-5.4 runs at 146.51 t/s and $15 per million tokens. The speed and cost advantages make GPT-5.1-Codex preferable for high-volume coding sessions.
Context and Multimodal Scope
Winner: GPT-5.4GPT-5.4 supports a 1.05M token context and adds file inputs alongside text and images. GPT-5.1-Codex is limited to 400k tokens and text-image inputs only, though it excels at maintaining coherence on large coding inputs.
Task Specialization
Winner: GPT-5.1-CodexGPT-5.1-Codex is explicitly tuned for extended coding workflows and visual-code integration. GPT-5.4 targets broader document-level and flexible multimodal tasks but lacks native audio or video support in both cases.
GPT-5.1-Codex
Pros
- +Strong performance on extended coding workflows
- +Effective integration of visual context with code
- +Handles very large inputs without losing coherence
Cons
- –Limited to text and image inputs only
- –High computational cost for maximum context
- –May require careful prompt engineering for complex tasks
GPT-5.4
Pros
- +Handles extremely large contexts
- +Seamless text-image-file integration
- +Strong at document-level tasks
Cons
- –No native audio or video support
- –Large context can increase latency
- –May need careful prompting for complex tasks
Summary: GPT-5.1-Codex vs GPT-5.4
Select GPT-5.1-Codex for speed, cost efficiency, and coding-centric multimodal work. Choose GPT-5.4 when maximum context size, higher intelligence, and file-inclusive workflows are required. The decision hinges on whether coding specialization or raw scale matters more for the use case.
Frequently asked questions
GPT-5.4 scores higher on intelligence and context size while GPT-5.1-Codex is faster and cheaper; neither is universally better.