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OpenAIGPT-5.4VSxAIGrok 4.20

Analysis by:the whichllmmodel Editorial Team|Updated: June 2026

Our Take

We recommend GPT-5.4 for its clear benchmark advantage, or the 1.9x cheaper Grok 4.20 only if your budget requires optimizing costs for very high-volume pipelines. While GPT-5.4 offers superior reasoning and coding, it carries a moderate price premium. Choose GPT-5.4 for quality, or Grok 4.20 for cost optimization.
WHY?
Benchmark Calculations & Evidence:
  • Coding Benchmarks: Both models were evaluated on the SWE-bench Pro benchmark. GPT-5.4 scored 57.7%, while Grok 4.20 scored 51.8%.
  • Reasoning Benchmarks: Both models were evaluated on the GPQA Diamond benchmark. GPT-5.4 scored 92.8%, while Grok 4.20 scored 90%.
  • Cost Efficiency: Grok 4.20 pricing ($2/M input, $6/M output) is 1.9x cheaper than GPT-5.4 ($2.5/M input, $15/M output).
  • Was this recommendation helpful?
    Model Specs

    GPT-5.4

    Benchmarks & Scores

    Coding (swe-bench-pro)Winner (+5.9%)
    57.7%

    complex codebases, multi-file repositories, and architectural planning

    Reasoning (gpqa-diamond)Winner (+2.8%)
    92.8%

    graduate-level science QA

    Cost & Context

    Cost (per 1M tokens)
    $5.63Input: $2.50 | Output: $15.00
    Context WindowLarger
    1.05M tokens
    Model Specs

    Grok 4.20

    Benchmarks & 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)1.9x cheaper
    $3.00Input: $2.00 | Output: $6.00
    Context Window
    1.05M tokens

    Frequently Asked Questions about GPT-5.4 vs Grok 4.20

    Grok 4.20 is cheaper than GPT-5.4. Grok 4.20 has a blended cost of $3.00/1M tokens, which is about 1.9x cheaper than GPT-5.4 at $5.63/1M tokens.

    GPT-5.4 is better for coding tasks on this benchmark. It scores 57.7% on swe-bench-pro (complex codebases, multi-file repositories, and architectural planning) compared to Grok 4.20 which scores 51.8%.

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