Claude Opus 4.5 vs Grok 4.5

Pick Grok 4.5 if you want the stronger benchmark profile. Claude Opus 4.5 only becomes the better choice if coding is the priority or you would rather avoid the extra latency and token burn of a reasoning model.

Grok 4.5 has the cleaner provisional overall profile here, landing at 75 versus 73. It is a real lead, but still close enough that category-level strengths matter more than the headline number.

Grok 4.5's sharpest advantage is in agentic, where it averages 83.3 against 62.6. The single biggest benchmark swing on the page is Terminal-Bench 2.0, 59.3% to 83.3%. Claude Opus 4.5 does hit back in coding, so the answer changes if that is the part of the workload you care about most.

Claude Opus 4.5 is also the more expensive model on tokens at $5.00 input / $25.00 output per 1M tokens, versus $2.00 input / $6.00 output per 1M tokens for Grok 4.5. That is roughly 4.2x on output cost alone. Grok 4.5 is the reasoning model in the pair, while Claude Opus 4.5 is not. That usually helps on harder chain-of-thought-heavy tests, but it can also mean more latency and more token spend in real use. Grok 4.5 gives you the larger context window at 500K, compared with 200K for Claude Opus 4.5.