GPT-5.4 vs Grok 4.20 (Reasoning)
Complete 2025 Comparison
Side-by-side comparison of GPT-5.4 and Grok 4.20 (Reasoning). Compare performance, pricing, capabilities, context windows, and more to choose the best AI model for your needs.
Quick Comparison
| Feature | GPT-5.4 | Grok 4.20 (Reasoning) | Winner |
|---|---|---|---|
| Provider | OpenAI | xAI | - |
| Context Window | 400,000 tokens | 2,000,000 tokens | Grok 4.20 (Reasoning) |
| Output Limit | 16,384 tokens | 32,768 tokens | Grok 4.20 (Reasoning) |
| Speed | deep | balanced | Grok 4.20 (Reasoning) |
| Vision Support | Yes | No | GPT-5.4 |
| Function Calling | Yes | Yes | Both |
| Reasoning | Yes | Yes | Both |
| Code Generation | Yes | No | GPT-5.4 |
| Total Capabilities | 8 | 7 | GPT-5.4 |
| Tier | max | max | - |
Performance Comparison
🚀GPT-5.4
Latest frontier model with breakthrough reasoning, multimodal understanding, and 400K context window. Major advances in agentic coding, instruction following, and creative generation.
🧠Grok 4.20 (Reasoning)
Latest Grok 4.20 reasoning model for deep analysis, multimodal planning, and longer agentic tasks.
Capabilities & Features
GPT-5.4 Capabilities
- ✓reasoning
- ✓vision
- ✓multimodal
- ✓analysis
- ✓function calling
- ✓code generation
- ✓thinking mode
- ✓long context
Grok 4.20 (Reasoning) Capabilities
- ✓reasoning
- ✓analysis
- ✓long context
- ✓multimodal
- ✓thinking mode
- ✓function calling
- ✓tool use
Which Should You Choose?
🚀Choose GPT-5.4 if you need:
- •Vision capabilities for image analysis and multimodal tasks
- •Advanced code generation and software development
- •OpenAI ecosystem integration
🧠Choose Grok 4.20 (Reasoning) if you need:
- •Larger context window (2,000,000 vs 400,000 tokens) for processing long documents or extensive conversations
- •xAI ecosystem integration
Best of Both Worlds
With JustSimpleChat, you don't have to choose! Access both GPT-5.4 and Grok 4.20 (Reasoning)in the same conversation. Switch models mid-chat, compare responses side-by-side, or let our smart routing automatically select the best model for each task.
Try Both Models FreeFrequently Asked Questions
Which is better, GPT-5.4 or Grok 4.20 (Reasoning)?
The choice between GPT-5.4 and Grok 4.20 (Reasoning) depends on your specific needs. GPT-5.4 excels at deep reasoning and complex tasks. Grok 4.20 (Reasoning) offers superior context handling with 2,000,000 tokens. Try both on JustSimpleChat to see which fits your workflow.
Is GPT-5.4 faster than Grok 4.20 (Reasoning)?
Speed comparison: GPT-5.4 is rated as "deep" while Grok 4.20 (Reasoning) is rated as "balanced". Both models offer similar response times. However, actual speed can vary based on request complexity, server load, and the specific task being performed.
Which costs less, GPT-5.4 or Grok 4.20 (Reasoning)?
Pricing comparison: Pricing varies by provider and usage tier. On JustSimpleChat, you can access both models with transparent usage tracking and flexible pricing plans.
Does GPT-5.4 have a larger context window than Grok 4.20 (Reasoning)?
Context window comparison: GPT-5.4 supports 400,000 input tokens, while Grok 4.20 (Reasoning) supports 2,000,000 tokens. Grok 4.20 (Reasoning) offers a 400% larger context window, ideal for large-scale document analysis.
Which is better for coding, GPT-5.4 or Grok 4.20 (Reasoning)?
For coding tasks: GPT-5.4 is specifically optimized for code generation tasks. Test both on JustSimpleChat with your actual code to find the best fit.
Can I use both GPT-5.4 and Grok 4.20 (Reasoning) on JustSimpleChat?
Yes! JustSimpleChat provides access to both GPT-5.4 and Grok 4.20 (Reasoning), along with 600+ other AI models. You can switch between models mid-conversation, compare responses side-by-side, or let our smart routing automatically select the best model for each task. Start with our free tier to try both models, or upgrade for higher usage limits and additional features.
What are the main differences between GPT-5.4 and Grok 4.20 (Reasoning)?
Key differences: 1) Context Window: GPT-5.4 (400,000 tokens) vs Grok 4.20 (Reasoning) (2,000,000 tokens). 2) Speed: deep vs balanced. 3) Capabilities: GPT-5.4 supports reasoning, vision, multimodal, analysis, function_calling, code_generation, thinking_mode, long_context, while Grok 4.20 (Reasoning) supports reasoning, analysis, long_context, multimodal, thinking_mode, function_calling, tool_use. 4) Provider: OpenAI vs xAI. 5) Use Cases: GPT-5.4 excels at latest frontier model with breakthrough reasoning, multimodal understanding, and 400k context window. major advances in agentic coding, instruction following, and creative generation., while Grok 4.20 (Reasoning) is optimized for latest grok 4.20 reasoning model for deep analysis, multimodal planning, and longer agentic tasks..
How do I choose between GPT-5.4 and Grok 4.20 (Reasoning)?
Choose GPT-5.4 if you need advanced reasoning capabilities. Choose Grok 4.20 (Reasoning) if you prioritize maximum context capacity. The best way to decide is to try both on JustSimpleChat with your actual use cases.
Is GPT-5.4 or Grok 4.20 (Reasoning) better for business use?
For business applications: GPT-5.4 is designed for enterprise use with 400,000 token context and advanced features. Consider factors like context window (GPT-5.4: 400,000, Grok 4.20 (Reasoning): 2,000,000), pricing, and specific capabilities. JustSimpleChat offers team plans with both models, centralized billing, and usage analytics.
Can I compare GPT-5.4 and Grok 4.20 (Reasoning) side-by-side?
Yes! On JustSimpleChat, you can compare GPT-5.4 and Grok 4.20 (Reasoning) side-by-side by using our model comparison feature. Send the same prompt to both models simultaneously and see how they respond. This helps you understand their different strengths, response styles, and performance characteristics for your specific use cases. Available on all plans including free tier.
Ready to Compare GPT-5.4 and Grok 4.20 (Reasoning)?
Try both models free on JustSimpleChat. No credit card required.
Start Comparing Now