SpaceXAI Launches Grok 4.5 Publicly, Claiming Opus-Class Performance at $2/M Input Tokens

My take: With Grok 4.5 going public today, SpaceXAI enters the frontier tier with a number worth analyzing: on SWE-Bench Pro, it uses an average of 15,954 output tokens per task, compared to 67,020 for Claude Opus 4.8 on the same benchmark. That's 4.2x less text generated to reach a comparable result, and at $2 per million input tokens, that efficiency translates into real savings per task.

That said, the benchmarks xAI publishes comparing itself to competitors deserve a critical read: when the company building the model also designs and runs the tests, the numbers have value but merit independent verification before being taken as final. The Artificial Analysis Intelligence Index, an independent source, ranks it fourth globally with a score of 54, behind Fable 5, Opus 4.8, and GPT-5.5.

For anyone building AI workflows or developing with the API, Grok 4.5 is worth a serious evaluation: competitive pricing, 500K-token context, and token efficiency that lowers cost per task. Does the output quality in your specific use cases justify moving it to production?