GPT-5.3-Instant and Grok 4.20 Beta don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Grok 4.20 Beta shipped 14 days before GPT-5.3-Instant, so benchmark comparisons should account for the intervening progress.

Published specifications for these two models are limited — see each model page for the latest details.

Direct benchmark comparisons are unavailable — GPT-5.3-Instant and Grok 4.20 Beta don't publish scores on any of the same benchmarks.