xAI: Grok 4.1 Fast vs OpenAI: GPT-5.4 Pro

Side-by-side comparison based on OpenRouter API data.

Key Differences

  • xAI: Grok 4.1 Fast is 150.0x cheaper than OpenAI: GPT-5.4 Pro for input tokens
  • xAI: Grok 4.1 Fast has 1.9x more context than OpenAI: GPT-5.4 Pro (2M vs 1.1M)
SpecxAI: Grok 4.1 FastOpenAI: GPT-5.4 Pro
ProviderxAIOpenAI
Context Length2M1.1M
Max Output30K128K
Input Price/1M$0.20$30
Output Price/1M$0.50$180
Cache Read/1M$0.05Free
Cache Write/1MFreeFree
Input ModalitiesText + ImageText + Image + File
Output ModalitiesTextText
TokenizerGrokGPT
ModeratedNoYes
xAI: Grok 4.1 Fast vs OpenAI: GPT-5.4 Pro -- AI Model Comparison | AIToolRank