Grok 4.3 Beta

Parameters

500B

Published

Apr 17, 2026

Grok 4.3 Beta is an AI model developed by xAI (United States), first published in April 2026. It works in the language domain, on tasks such as language modeling/generation and question answering.

Epoch AI has no training-compute estimate for this model. The model has 500,000,000,000 parameters.

Access: Hosted access (no API). Its weights are not openly released. Epoch AI rates the confidence of this record as likely.

Full record

Organization: xAI
Country of organization: United States
Domain: Language
Task: Language modeling/generation, Question answering
Parameters: 500,000,000,000
Model accessibility: Hosted access (no API)
Open weights: No
Epoch confidence: Likely

Benchmark results

01

Epoch Capabilities Index

ECI Score

149