Claude Opus 4.6 vs Grok 4 Fast

Side-by-side benchmark comparison across coding, math, reasoning, speed, and pricing.

Claude Opus 4.6 by Anthropic wins on 9 of 14 benchmarks against Grok 4 Fast by xAI, which leads on 5. This head-to-head comparison covers coding, math, reasoning, speed, and pricing metrics from the AI Value Index.

Category-by-Category Breakdown

General Intelligence: In general intelligence, Claude Opus 4.6 scores 1496 on Chatbot Arena ELO compared to Grok 4 Fast's 1370, while Claude Opus 4.6 scores 82.0% on MMLU-Pro compared to Grok 4 Fast's 80.0%.

Coding: In coding, Claude Opus 4.6 scores 93.5% on HumanEval+ compared to Grok 4 Fast's 85.0%, while Claude Opus 4.6 scores 80.8% on SWE-bench Verified compared to Grok 4 Fast's 48.0%, while Claude Opus 4.6 scores 72.0% on LiveCodeBench compared to Grok 4 Fast's 52.0%.

Math: In math, Claude Opus 4.6 scores 92.0% on MATH compared to Grok 4 Fast's 84.0%, while Claude Opus 4.6 scores 97.0% on GSM8K compared to Grok 4 Fast's 94.0%.

Reasoning: In reasoning, Claude Opus 4.6 scores 91.3% on GPQA Diamond compared to Grok 4 Fast's 60.0%, while Claude Opus 4.6 scores 60.0% on ARC-AGI compared to Grok 4 Fast's 38.0%.

Context: In context, Grok 4 Fast scores 256K on Context Length compared to Claude Opus 4.6's 200K.

Pricing Comparison

Claude Opus 4.6 costs $5.0/1M input tokens and $25.0/1M output tokens, while Grok 4 Fast costs $0.20/1M input and $0.50/1M output. Grok 4 Fast is the more affordable option for API usage.

Speed Comparison

Claude Opus 4.6 generates output at 68 tok/s compared to Grok 4 Fast's 110 tok/s, and the time to first token is 1680 ms for Claude Opus 4.6 versus 220 ms for Grok 4 Fast. Grok 4 Fast delivers faster throughput.

Verdict

For developers prioritizing coding and general intelligence and math, Claude Opus 4.6 has the edge. For those who value affordability and speed, Grok 4 Fast is the stronger choice.

Claude Opus 4.6 vs Grok 4 Fast — FAQ

Which is better, Claude Opus 4.6 or Grok 4 Fast?

Claude Opus 4.6 wins on more benchmarks overall (9 vs 5). However, the best choice depends on your specific needs — each model excels in different areas.

How does Claude Opus 4.6 compare to Grok 4 Fast for coding?

Claude Opus 4.6 is better for coding, scoring 80.8% on SWE-bench Verified compared to 48.0%. SWE-bench tests real-world software engineering by resolving actual GitHub issues.

Is Claude Opus 4.6 cheaper than Grok 4 Fast?

Yes, Grok 4 Fast is cheaper. Claude Opus 4.6 costs $5.0/1M input and $25.0/1M output tokens. Grok 4 Fast costs $0.20/1M input and $0.50/1M output tokens.

Which is faster, Claude Opus 4.6 or Grok 4 Fast?

Grok 4 Fast is faster, generating output at 110 tok/s compared to 68 tok/s. Faster output speed means shorter wait times for API responses.

What benchmarks does the Claude Opus 4.6 vs Grok 4 Fast comparison cover?

This comparison covers 14 benchmarks including Chatbot Arena ELO, MMLU-Pro, HumanEval+, MATH, SWE-bench Verified, GPQA Diamond, Output Speed, Time to First Token, and more. Metrics span general intelligence, coding, math, reasoning, speed, and cost categories.