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DeepSeek V4-Pro vs Grok 4 Fast

Detailed pricing comparison and cost analysis.

Updated September 2026

Cost Simulator

DeepSeek V4-Pro Cost
$2.11
Grok 4 Fast Cost
$0.30
Grok 4 Fast is 86% cheaper
FeatureDeepSeek V4-ProGrok 4 Fast
ProviderDeepSeekxAI
Input Price (1M)$1.32$0.20
Output Price (1M)$3.96$0.50
Context Window1,000,0002,000,000

Verdict

DeepSeek V4-Pro costs $1.32 per 1M input tokens and $3.96 per 1M output tokens. Grok 4 Fast costs $0.20 per 1M input tokens and $0.50 per 1M output tokens. Grok 4 Fast is 85% cheaper on input tokens than DeepSeek V4-Pro. For output tokens, Grok 4 Fast is the more affordable option at $0.50/1M vs $3.96.

On context window, Grok 4 Fast supports 2,000,000 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 DeepSeek V4-Pro

  • ✓ You are already integrated with DeepSeek

When to choose Grok 4 Fast

  • ✓ You need the lowest input token cost ($ 0.20/1M)
  • ✓ Your workload is output-heavy — Grok 4 Fast generates text cheaper
  • ✓ You need a larger context window (2,000,000 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 DeepSeek V4-Pro cheaper than Grok 4 Fast?

Grok 4 Fast is cheaper on input tokens at $0.20/1M vs $1.32/1M for DeepSeek V4-Pro — a 85% saving.

What is the context window of DeepSeek V4-Pro vs Grok 4 Fast?

DeepSeek V4-Pro has a 1,000,000-token context window. Grok 4 Fast has a 2,000,000-token context window. Grok 4 Fast supports the larger context, suitable for longer documents and agentic workflows.

Which model is better: DeepSeek V4-Pro or Grok 4 Fast?

The best choice depends on your use case. For cost efficiency on input tokens, Grok 4 Fast is the cheaper option. For maximum context length, Grok 4 Fast supports 2,000,000 tokens. Use the comparison table above to find the right fit for your workload.