GPT-5.1-Codex-Mini vs GPT-5.5
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-Mini if you need
- ✓higher intelligence and maximum context for complex multimodal analysis
- ✓native file and image support in document-heavy tasks
- ✓flexible multimodal workflows beyond basic image+text
- ✓largest possible context window despite potential latency
Choose GPT-5.5 if you need
- ✓fastest output speed for extended technical sessions
- ✓lowest cost at $2 per 1M tokens on coding projects
- ✓strong coding specialization with 400k context
- ✓image+text multimodal needs where speed matters most
Verdict
GPT-5.5 leads on raw intelligence (43.5 vs 30.6) and context size (1.05M vs 400k tokens) with native file support for document-heavy multimodal work, while GPT-5.1-Codex-Mini dominates on speed (215.76 vs 58.13 t/s) and price ($2 vs $30 per 1M tokens) for coding-focused tasks. GPT-5.5 offers broader multimodal flexibility at the cost of higher latency and expense; GPT-5.1-Codex-Mini trades depth for efficiency in technical workflows.
GPT-5.1-Codex-Mini vs GPT-5.5: side by side
| Spec | GPT-5.1-Codex-Mini | GPT-5.5 | Winner |
|---|---|---|---|
| Intelligence | 30.6 | 43.5 | GPT-5.5 |
| Output speed | 216 t/s | 58 t/s | GPT-5.1-Codex-Mini |
| Output price | $2.00/1M | $30.00/1M | GPT-5.1-Codex-Mini |
| Context | 400K | 1050K | GPT-5.5 |
| Params | — | — | Tie |
| Provider | OpenAI | OpenAI | Tie |
Detailed analysis
Intelligence
Winner: GPT-5.5GPT-5.5 scores 43.5 on the intelligence index compared to 30.6 for GPT-5.1-Codex-Mini. This gap favors GPT-5.5 for tasks requiring deeper reasoning across modalities. GPT-5.1-Codex-Mini's lower score aligns with its noted limitation on complex reasoning depth.
Speed & Pricing
Winner: GPT-5.1-Codex-MiniGPT-5.1-Codex-Mini delivers 215.76 tokens per second at $2 per 1M tokens versus GPT-5.5's 58.13 t/s at $30 per 1M. The speed advantage supports extended technical workflows while the price difference is substantial. GPT-5.5's larger context may further increase latency as noted in its limitations.
Context Window
Winner: GPT-5.5GPT-5.5 provides a 1.05M token context window compared to 400k for GPT-5.1-Codex-Mini. Both support very large contexts suitable for extended inputs, but GPT-5.5's size is more than double. This makes GPT-5.5 preferable for document-heavy multimodal tasks.
Multimodal Capabilities
Winner: GPT-5.5GPT-5.5 includes native support for files and images with flexible multimodal workflows. GPT-5.1-Codex-Mini is limited to image and text modalities with coding specialization. Neither supports native audio or video.
GPT-5.1-Codex-Mini
Pros
- +Very large context window
- +Strong coding specialization
- +Native image + text support
Cons
- –Mini variant may have reduced depth on complex reasoning
- –Limited to image and text modalities
- –Trade-off between context size and response speed
GPT-5.5
Pros
- +Extremely large context window
- +Native support for files and images
- +Flexible multimodal workflows
Cons
- –No native audio or video support
- –Large context may increase latency
- –Performance depends on input quality across modalities
Summary: GPT-5.1-Codex-Mini vs GPT-5.5
Choose GPT-5.5 when intelligence, maximum context, and file support are priorities despite higher cost and slower speed. Select GPT-5.1-Codex-Mini for speed, affordability, and coding tasks. The models serve different multimodal priorities within OpenAI's lineup.
Frequently asked questions
GPT-5.5 is stronger on intelligence and context while GPT-5.1-Codex-Mini leads on speed and price; neither is universally better.