Grok 4.20 Beta Reasoning 0309

Before switching production traffic to Grok 4.20, run a pilot on a representative slice of your traffic and check output quality, latency at peak concurrency, and cost per request. Verify the error and retry behaviour, and confirm the request limits you depend on match your plan.

Grok 4.20 was released on 2026-03-10. Its catalog status is stable. Check the model page for deprecation notices before you build a long-lived integration on it.

Reasoning tokens are billed as output on Grok 4.20, at $6.0000 per 1M tokens. They are generated before the visible answer and count toward both latency and spend, so a higher reasoning setting costs more even when the final answer is short.

Grok 4.20 is billed per use and the record publishes no free-tier allowance. The current published rates are input $2.0000 per 1M tokens and output $6.0000 per 1M tokens. Trial credit or promotional quota is tied to your account rather than to the model, so check the console before planning around a free tier.

Grok 4.20 is a reasoning model. Reasoning effort can be tuned per request. Lower effort settings cut reasoning tokens and cost for routine work; reserve higher settings for problems that need deeper search. Measure quality at two or three settings before fixing one in production.