GPT-5.1 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-5.1 if you need
- ✓Choose GPT-5.1 if you need integration specifically with OpenAI infrastructure.
- ✓Choose GPT-5.1 if your workloads fit comfortably within a 400k token context.
- ✓Choose GPT-5.1 if you prioritize the listed strong multimodal integration for images, text, and files.
Choose Grok 4.20 if you need
- ✓Choose Grok 4.20 if you need the highest intelligence index of 49.3.
- ✓Choose Grok 4.20 if you need faster output at 168.03 t/s and lower cost at $2.5 per 1M tokens.
- ✓Choose Grok 4.20 if you require up to 2M token context for large-scale inputs.
- ✓Choose Grok 4.20 if you want native text, image, and file support in a single model.
Verdict
Grok 4.20 leads across intelligence (49.3 vs 27.4), speed (168.03 t/s vs 115.83 t/s), price ($2.5 vs $10 per 1M), and context (2M vs 400k tokens). GPT-5.1 offers no measurable advantages in the provided data and shares identical multimodal limitations with no audio or video support.
GPT-5.1 vs Grok 4.20: side by side
| Spec | GPT-5.1 | Grok 4.20 | Winner |
|---|---|---|---|
| Intelligence | 27.4 | 49.3 | Grok 4.20 |
| Output speed | 116 t/s | 168 t/s | Grok 4.20 |
| Output price | $10.00/1M | $2.50/1M | Grok 4.20 |
| Context | 400K | 2000K | Grok 4.20 |
| Params | — | — | Tie |
| Type | Proprietary | Proprietary | Tie |
| Provider | OpenAI | xAI | Tie |
Detailed analysis
Intelligence
Winner: Grok 4.20Grok 4.20 scores 49.3 on the intelligence index compared to GPT-5.1's 27.4. No other performance metrics are provided to offset this gap.
Speed and Pricing
Winner: Grok 4.20Grok 4.20 delivers higher output speed at 168.03 t/s versus 115.83 t/s and costs $2.5 per 1M tokens versus $10. Both models are proprietary with unspecified parameter counts.
Context Window
Winner: Grok 4.20Grok 4.20 supports up to 2 million tokens while GPT-5.1 supports 400,000. Both note potential latency risks at maximum context sizes.
Multimodal Capabilities
Winner: TieBoth models provide native support for images, text, and files with no audio or video modalities. Strengths listed for each emphasize multimodal integration in a single model.
GPT-5.1
Pros
- +Very large context window
- +Native support for images, text, and files
- +Strong multimodal integration
Cons
- –No audio or video modalities
- –Performance details unverified beyond specs
- –Potential latency with maximum context
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-5.1 vs Grok 4.20
Grok 4.20 outperforms GPT-5.1 on every quantified dimension and should be selected for most multimodal workloads. GPT-5.1 only makes sense when OpenAI provider compatibility is a hard requirement.
Frequently asked questions
Grok 4.20 is better overall based on higher intelligence, speed, lower price, and larger context.