xAI dropped Grok 4.5 into the market on July 8, 2026, and it wasted no time making a statement. The model posted a 29.0% resolution rate on the SWE Marathon benchmark, a test designed to measure how well AI handles real-world software engineering tasks at scale.
To put that number in context, Claude Opus 4.8 came in at 26.0% on the same benchmark. Fable, another competitive entry, landed at 24.0%. Grok 4.5 cleared both by a meaningful margin.
What the benchmarks actually say
Grok 4.5 also posted an 83.3% resolution rate on Terminal-Bench 2.1, a separate evaluation focused on terminal-based development workflows.
Worth noting: independent verification of these figures is still catching up. Many results at this stage of a model launch are based on vendor evaluations, so the scores should be read as directional rather than definitive. That caveat applies equally to every model in this comparison.
