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Grok 4.1 Fast vs Qwen3.8-Flash

Detailed pricing comparison and cost analysis.

Updated September 2026

Cost Simulator

Grok 4.1 Fast Cost
$0.30
Qwen3.8-Flash Cost
$0.24
Qwen3.8-Flash is 19% cheaper
FeatureGrok 4.1 FastQwen3.8-Flash
ProviderxAIAlibaba
Input Price (1M)$0.20$0.15
Output Price (1M)$0.50$0.47
Context Window2,000,0001,000,000

Verdict

Grok 4.1 Fast costs $0.20 per 1M input tokens and $0.50 per 1M output tokens. Qwen3.8-Flash costs $0.15 per 1M input tokens and $0.47 per 1M output tokens. Qwen3.8-Flash is 25% cheaper on input tokens than Grok 4.1 Fast. For output tokens, Qwen3.8-Flash is the more affordable option at $0.47/1M vs $0.50.

On context window, Grok 4.1 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 Grok 4.1 Fast

  • ✓ You need a larger context window (2,000,000 tokens)
  • ✓ You are already integrated with xAI

When to choose Qwen3.8-Flash

  • ✓ You need the lowest input token cost ($ 0.15/1M)
  • ✓ Your workload is output-heavy — Qwen3.8-Flash generates text cheaper
  • ✓ You are already integrated with Alibaba

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 Grok 4.1 Fast cheaper than Qwen3.8-Flash?

Qwen3.8-Flash is cheaper on input tokens at $0.15/1M vs $0.20/1M for Grok 4.1 Fast — a 25% saving.

What is the context window of Grok 4.1 Fast vs Qwen3.8-Flash?

Grok 4.1 Fast has a 2,000,000-token context window. Qwen3.8-Flash has a 1,000,000-token context window. Grok 4.1 Fast supports the larger context, suitable for longer documents and agentic workflows.

Which model is better: Grok 4.1 Fast or Qwen3.8-Flash?

The best choice depends on your use case. For cost efficiency on input tokens, Qwen3.8-Flash is the cheaper option. For maximum context length, Grok 4.1 Fast supports 2,000,000 tokens. Use the comparison table above to find the right fit for your workload.