It was (is?) free with eg. opencode -- so, open-source coding agent + free sota model, it's hard to resist. That said, grok fast is fast, but not that great when compared to the other top tier models.

It's a 1.7 trillion token free model. Why wouldn't you try it?

I've been testing free models for coding hobby projects after I burnt through way too many expensive tokens on Replit and Claude. Grok wasn't great, kept getting into loops for me. I had better results using KAT coder on opencode (also free).

Kilo Code lets people use Grok Code Fast 1 for free, using OpenRouter as the provider. And Grok 4.1 Fast was completely free directly on OpenRouter for some time after its release.

So yeah, their statistics are inflated quite a bit, since most of that usage was not paid for, or at least not by the end user.

According to https://openrouter.ai/rankings, lots of people are using it - presumably because it performs well and provides value.