Grok 4.20

Parameters

500B

Published

Feb 17, 2026

Grok 4.20 is an AI model developed by xAI (United States), first published in February 2026. It works in the language domain, on tasks such as language modeling/generation.

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

Access: API access. 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
Parameters: 500,000,000,000
Model accessibility: API access
Open weights: No
Epoch confidence: Likely

Benchmark results

01	Vending-Bench 2	Score	4662.8
02	WebDev Arena	Arena Score	1395.2
03	ALE Bench	Performance	1150.3
04	Epoch Capabilities Index	ECI Score	152.6
05	ForecastBench	Overall score	61.4
06	ARC-AGI	Score	0.9
07	ARC-AGI-2	Score	0.65
08	Terminal-Bench	Accuracy mean	0.57
09	WeirdML	Accuracy	0.52
10	CL Bench	Overall	0.22
11	CL Bench Life	Overall	0.12
12	Blueprint Bench 2	Score	0