GoogleGemini 3 FlashVSxAIGrok 4.20
Our Take
We recommend Grok 4.20 for complex complex codebases, multi-file repositories, and architectural planning, or the 2.7x cheaper Gemini 3 Flash if your workflow is limited to multi-file code and clearly defined tasks. While they share very similar reasoning capabilities, Grok 4.20 handles repository-scale projects whereas Gemini 3 Flash excels at basic functions and scripts. Choose Grok 4.20 for architectural codebase planning, or Gemini 3 Flash to save on API costs for simple scripts.
▶WHY?
Benchmark Calculations & Evidence:
Coding Evaluation: Gemini 3 Flash was evaluated on SWE-bench Verified (scoring 78%), while Grok 4.20 was evaluated on SWE-bench Pro (scoring 51.8%).
Reasoning Accuracy: Both models were evaluated on the GPQA Diamond benchmark. Gemini 3 Flash scored 90.4%, while Grok 4.20 scored 90%.
Cost Efficiency: Gemini 3 Flash pricing ($0.5/M input, $3/M output) is 2.7x cheaper than Grok 4.20 ($2/M input, $6/M output).
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Benchmarks & Scores
Coding (swe-bench-verified)
78%multi-file code and clearly defined tasks
Reasoning (gpqa-diamond)Winner (+0.4%)
90.4%graduate-level science QA
Cost & Context
Cost (per 1M tokens)2.7x cheaper
$1.13Input: $0.50 | Output: $3.00Context Window
1.05M tokensBenchmarks & Scores
Coding (swe-bench-pro)
51.8%complex codebases, multi-file repositories, and architectural planning
Reasoning (gpqa-diamond)
90%graduate-level science QA
Cost & Context
Cost (per 1M tokens)
$3.00Input: $2.00 | Output: $6.00Context Window
1.05M tokensFrequently Asked Questions about Gemini 3 Flash vs Grok 4.20
Gemini 3 Flash is cheaper than Grok 4.20. Gemini 3 Flash has a blended cost of $1.13/1M tokens, which is about 2.7x cheaper than Grok 4.20 at $3.00/1M tokens.
For coding tasks, Gemini 3 Flash scores 78% on swe-bench-verified (multi-file code and clearly defined tasks), while Grok 4.20 scores 51.8% on swe-bench-pro (complex codebases, multi-file repositories, and architectural planning).
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