GPT-4o vs Grok 4.20 Beta
Detailed pricing comparison and cost analysis.
Updated September 2026
Cost Simulator
| Feature | GPT-4o | Grok 4.20 Beta |
|---|---|---|
| Provider | OpenAI | xAI |
| Input Price (1M) | $2.50 | $1.25 |
| Output Price (1M) | $10.00 | $2.50 |
| Context Window | 128,000 | 1,000,000 |
Verdict
GPT-4o costs $2.50 per 1M input tokens and $10.00 per 1M output tokens. Grok 4.20 Beta costs $1.25 per 1M input tokens and $2.50 per 1M output tokens. Grok 4.20 Beta is 50% cheaper on input tokens than GPT-4o. For output tokens, Grok 4.20 Beta is the more affordable option at $2.50/1M vs $10.00.
On context window, Grok 4.20 Beta supports 1,000,000 tokens — meaning it can fit more conversation history, documents, or code in a single request. This matters for RAG pipelines, long document analysis, and agentic workflows where context builds up over many turns.
When to choose GPT-4o
- ✓ You are already integrated with OpenAI
When to choose Grok 4.20 Beta
- ✓ You need the lowest input token cost ($ 1.25/1M)
- ✓ Your workload is output-heavy — Grok 4.20 Beta generates text cheaper
- ✓ You need a larger context window (1,000,000 tokens)
- ✓ You are already integrated with xAI
Use the calculator above to simulate your specific workload and find the exact break-even point. For most applications, the cheapest model is the one that minimises your total monthly bill given your input-to-output token ratio.
Frequently Asked Questions
Is GPT-4o cheaper than Grok 4.20 Beta? ▼
Grok 4.20 Beta is cheaper on input tokens at $1.25/1M vs $2.50/1M for GPT-4o — a 50% saving.
What is the context window of GPT-4o vs Grok 4.20 Beta? ▼
GPT-4o has a 128,000-token context window. Grok 4.20 Beta has a 1,000,000-token context window. Grok 4.20 Beta supports the larger context, suitable for longer documents and agentic workflows.
Which model is better: GPT-4o or Grok 4.20 Beta? ▼
The best choice depends on your use case. For cost efficiency on input tokens, Grok 4.20 Beta is the cheaper option. For maximum context length, Grok 4.20 Beta supports 1,000,000 tokens. Use the comparison table above to find the right fit for your workload.