xAI

Private

Foundation Models

Founded 2023Memphis, TN (now SpaceX subsidiary)~2,500 employees

Website

Valuation

$250B standalone xAI; $1.25T combined SpaceX-xAI entity (Feb 2026)

Total Funding

$42B+ cumulative

Profit Status

Pre-profit; ~$500M ARR, burning ~$1B/month

Employees

~2,500

About xAI

xAI is now the AI division of SpaceX after the largest merger in history (Feb 2026, $1.25T combined entity). Develops the Grok model family with real-time X data access. Grok 4 (Jul 2025) and Grok 4.3 (Apr 2026) are current frontier models. Colossus supercluster (220K+ GPUs) leased entirely to Anthropic in May 2026 after xAI migrated to Colossus 2.

Company History

Founded Jul 2023. Grok-1 open-sourced Mar 2024. Built Colossus (300MW, 220K+ GPUs). Grok 3 (Feb 2025) - #1 AIME at launch. Grok 4 released Jul 9, 2025. $20B Series E Jan 2026. SpaceX acquired xAI in all-stock deal Feb 2, 2026 - combined entity valued at $1.25T (largest merger ever). Grok 4.3 launched Apr 30, 2026 at aggressively low API pricing ($1.25/$2.50 per million tokens). Colossus 1 leased to Anthropic May 2026; xAI training on Colossus 2. Grok 5 in training at ~10 trillion parameters.

AI Models & Benchmarks

Grok 4.3

Multimodal

Current flagship. Aggressively priced API ($1.25/M input, $2.50/M output). Voice cloning suite included.

1M ctxApr 2026

Benchmarks

AIME~95

GPQA~88

SWE-bench~75

Grok 4.1 Fast

LLM

Fast inference tier. $0.20/$0.50 per million tokens. 2M context window.

2M ctx2026

Grok 4

Multimodal

Trained on Colossus (200K GPUs). 100x more training compute than Grok 2. 10x more RL. #1 STEM benchmarks at launch.

256K ctxJul 2025

Benchmarks

AIME math~95

GPQA~88

Humanity's Last Exam~45%

Aurora

Image Gen

Text-to-image model integrated into Grok. Grok Imagine API launched Jan 28, 2026.

Aug 2024

Company Timeline

Jul 2023
xAI founded by Elon Musk with 12 researchers
Nov 2023
Grok-0 beta released to X Premium subscribers
Mar 2024
Grok-1 weights open-sourced (314B MoE, Apache 2.0)
May 2024
$6B raise - Colossus supercomputer announced (100K H100s)
Aug 2024
Grok-2 with Aurora image generation

Products & Services

Grok 4.3Grok 4Grok 4.1 FastAurora (image gen)Grok Imagine APISuperGrokGrok Business/Enterprise

Company Details

Focus Area

Foundation Models

Stage

Private

Founded

2023

Headquarters

Memphis, TN (now SpaceX subsidiary)