Gemini 2.5 Flash Preview 05-20 (thinking) vs xAI: Grok 4 Fast (free)
Compare Gemini 2.5 Flash Preview 05-20 (thinking) by Google AI against xAI: Grok 4 Fast (free) by xAI, context windows of 1.0M vs 2.0M, tested across 11 shared challenges. Updated April 2026.
Which is better, Gemini 2.5 Flash Preview 05-20 (thinking) or xAI: Grok 4 Fast (free)?
Gemini 2.5 Flash Preview 05-20 (thinking) and xAI: Grok 4 Fast (free) are both competitive models. Gemini 2.5 Flash Preview 05-20 (thinking) costs $0.15/M input tokens vs $0/M for xAI: Grok 4 Fast (free). Context windows: 1049K vs 2000K tokens. Compare their real outputs side by side below.
Key Differences Between Gemini 2.5 Flash Preview 05-20 (thinking) and xAI: Grok 4 Fast (free)
Gemini 2.5 Flash Preview 05-20 (thinking) is made by google while xAI: Grok 4 Fast (free) is from xai. Gemini 2.5 Flash Preview 05-20 (thinking) has a 1049K token context window compared to xAI: Grok 4 Fast (free)'s 2000K. On pricing, Gemini 2.5 Flash Preview 05-20 (thinking) costs $0.15/M input tokens vs $0/M for xAI: Grok 4 Fast (free).
No community votes yet. On paper, xAI: Grok 4 Fast (free) has the edge — bigger model tier, newer, bigger context window.
Style Comparison
xAI: Grok 4 Fast (free) uses 56.3x more hedging
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Some models write identically. You are paying for the brand.
178 models fingerprinted across 32 writing dimensions. Free research.
185x
price gap between models that write identically
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12
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279 AI models invented the same fake scientist.
We read every word. 250 models. 2.14 million words. This is what we found.
