GPT-5 Codex vs GPT-5 Nano
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 Codex if you need
- ✓Choose GPT-5 Nano if you need faster responses at 170 t/s with very large contexts.
- ✓Choose GPT-5 Nano if you need support for text, image, and file inputs at low cost.
- ✓Choose GPT-5 Nano if you need lightweight handling of extended document tasks.
- ✓Choose GPT-5 Nano if you need practical multimodal work without high resource demands.
Choose GPT-5 Nano if you need
- ✓Choose GPT-5 Codex if you need higher intelligence (44.6 index) for complex tasks.
- ✓Choose GPT-5 Codex if you need strong coding specialization with text and image reasoning.
- ✓Choose GPT-5 Codex if you need unified multimodal performance on large-scale inputs.
- ✓Choose GPT-5 Codex if you need maximum capability depth despite higher cost.
Verdict
GPT-5 Codex leads in raw intelligence (44.6 vs 26.8) and coding specialization, making it stronger for complex reasoning and unified text-image tasks. GPT-5 Nano wins on speed (170 t/s vs 149.9 t/s), price ($0.4 vs $10 per 1M), and broader file input support while matching the 400k context. The choice hinges on whether capability depth or efficiency and cost matter more.
GPT-5 Codex vs GPT-5 Nano: side by side
| Spec | GPT-5 Codex | GPT-5 Nano | Winner |
|---|---|---|---|
| Intelligence | 44.6 | 26.8 | GPT-5 Codex |
| Output speed | 150 t/s | 170 t/s | GPT-5 Nano |
| Output price | $10.00/1M | $0.40/1M | GPT-5 Nano |
| Context | 400K | 400K | Tie |
| Params | — | — | Tie |
| Type | Proprietary | Proprietary | Tie |
| Provider | OpenAI | OpenAI | Tie |
Detailed analysis
Intelligence
Winner: GPT-5 CodexGPT-5 Codex scores 44.6 on intelligence_index compared to 26.8 for GPT-5 Nano. This gap indicates stronger performance on complex reasoning and coding. Both share the same 400k context window.
Speed
Winner: GPT-5 NanoGPT-5 Nano outputs at 170.06 tokens per second versus 149.9 for GPT-5 Codex. Its lightweight design supports faster responses. Both handle 400k context but Nano does so more efficiently per the listed strengths.
Pricing
Winner: GPT-5 NanoGPT-5 Nano costs $0.4 per million tokens while GPT-5 Codex costs $10 per million. The 25x price difference favors Nano for high-volume use. Both are proprietary OpenAI models with identical context sizes.
Multimodal Inputs
Winner: GPT-5 NanoGPT-5 Nano explicitly supports text, image, and file inputs. GPT-5 Codex is limited to text and static images. Nano's file support provides an edge for document-oriented multimodal work.
GPT-5 Codex
Pros
- +Handles extremely large inputs effectively
- +Strong coding specialization
- +Unified text and image reasoning
Cons
- –High resource demands with maximum context
- –Limited to text and static images
- –Potential coherence loss in very long outputs
GPT-5 Nano
Pros
- +Handles very large contexts efficiently
- +Supports text, image, and file inputs
- +Lightweight design for faster responses
- +Practical for extended document tasks
Cons
- –Lower capability depth than full-scale models
- –May struggle with highly complex reasoning
- –Trade-off in advanced task performance
Summary: GPT-5 Codex vs GPT-5 Nano
Select GPT-5 Nano for speed, low cost, and file-inclusive multimodal tasks at 400k context. Select GPT-5 Codex when higher intelligence and coding strength justify the premium price. The models trade capability depth for efficiency.
Frequently asked questions
GPT-5 Codex is better for intelligence and coding; GPT-5 Nano is better for speed, price, and file inputs. Neither dominates all dimensions.