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GPT-5.4 mini vs Grok 4.20 Beta

Detailed pricing comparison and cost analysis.

Updated September 2026

Cost Simulator

GPT-5.4 mini Cost
$1.65
Grok 4.20 Beta Cost
$1.75
GPT-5.4 mini is 6% cheaper
FeatureGPT-5.4 miniGrok 4.20 Beta
ProviderOpenAIxAI
Input Price (1M)$0.75$1.25
Output Price (1M)$4.50$2.50
Context Window400,0001,000,000

Verdict

GPT-5.4 mini costs $0.75 per 1M input tokens and $4.50 per 1M output tokens. Grok 4.20 Beta costs $1.25 per 1M input tokens and $2.50 per 1M output tokens. GPT-5.4 mini is 40% cheaper on input tokens than Grok 4.20 Beta. For output tokens, Grok 4.20 Beta is the more affordable option at $2.50/1M vs $4.50.

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-5.4 mini

  • ✓ You need the lowest input token cost ($ 0.75/1M)
  • ✓ You are already integrated with OpenAI

When to choose Grok 4.20 Beta

  • ✓ 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-5.4 mini cheaper than Grok 4.20 Beta?

GPT-5.4 mini is cheaper on input tokens at $0.75/1M vs $1.25/1M for Grok 4.20 Beta — a 40% saving.

What is the context window of GPT-5.4 mini vs Grok 4.20 Beta?

GPT-5.4 mini has a 400,000-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-5.4 mini or Grok 4.20 Beta?

The best choice depends on your use case. For cost efficiency on input tokens, GPT-5.4 mini 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.