GPT-5.3-Codex vs Grok 4.20
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-5.3-Codex if you need
- ✓programming workflows with higher intelligence requirements
- ✓specialized coding tasks leveraging its 44.3 index
- ✓extensive but focused 400k context handling for code
- ✓diverse input types within a coding-oriented model
Choose Grok 4.20 if you need
- ✓extremely large contexts up to 2M tokens
- ✓high output speed at 221.59 t/s for faster responses
- ✓lower cost at $2.5 per million tokens
- ✓native multimodal support for text, image, and files in one model
Verdict
GPT-5.3-Codex leads in intelligence and coding specialization with a 44.3 index versus Grok 4.20's 37, making it stronger for programming workflows despite its smaller 400k context. Grok 4.20 wins on speed at 221.59 t/s versus 101.59 t/s, price at $2.5/M versus $14/M, and context size up to 2M tokens for handling massive multimodal inputs. The choice hinges on whether users prioritize coding-focused intelligence or raw scale and efficiency.
GPT-5.3-Codex vs Grok 4.20: side by side
| Spec | GPT-5.3-Codex | Grok 4.20 | Winner |
|---|---|---|---|
| Intelligence | 44.3 | 37 | GPT-5.3-Codex |
| Output speed | 93 t/s | 219 t/s | Grok 4.20 |
| Output price | $14.00/1M | $2.50/1M | Grok 4.20 |
| Context | 400K | 2000K | Grok 4.20 |
| Params | — | — | Tie |
| Provider | OpenAI | xAI | Tie |
Detailed analysis
Intelligence
Winner: GPT-5.3-CodexGPT-5.3-Codex scores 44.3 on the intelligence index compared to Grok 4.20's 37. This edge aligns with its specialization for programming workflows. Grok remains capable but trails in this metric.
Speed
Winner: Grok 4.20Grok 4.20 delivers 221.59 tokens per second, more than double GPT-5.3-Codex's 101.59 t/s. Its faster output suits high-volume or latency-sensitive multimodal tasks. GPT-5.3-Codex is slower by comparison.
Pricing
Winner: Grok 4.20Grok 4.20 costs $2.5 per million tokens while GPT-5.3-Codex is priced at $14 per million. The fourfold difference favors Grok for budget-conscious or high-volume use. Both are proprietary models from their respective providers.
Context & Modalities
Winner: Grok 4.20Grok 4.20 supports up to 2M tokens versus GPT-5.3-Codex's 400k, with native text-image-file integration. GPT-5.3-Codex offers extensive context handling but in a narrower coding focus. Neither lists audio or video support.
GPT-5.3-Codex
Pros
- +Specialized for programming workflows
- +Extensive context handling
- +Support for diverse input types
Cons
- –Narrower focus than general-purpose models
- –Performance tied to input quality
Grok 4.20
Pros
- +Handles extremely large contexts up to 2M tokens
- +Native support for text, image, and file inputs
- +Multimodal integration in a single model
Cons
- –No audio or video modality support
- –Very large context can increase latency
- –Performance depends on input quality and structure
Summary: GPT-5.3-Codex vs Grok 4.20
Select GPT-5.3-Codex for coding-intensive multimodal work that benefits from its higher intelligence score. Choose Grok 4.20 when maximum context, speed, and lower cost are priorities. The models serve overlapping multimodal needs but diverge sharply on specialization versus scale.
Frequently asked questions
GPT-5.3-Codex is better for programming workflows due to its 44.3 intelligence index and coding specialization, while Grok 4.20 is better for large-scale multimodal tasks thanks to 2M context and higher speed.