Grok 4 API

xAI Grok 4 Description

Grok 4 is the latest large language model from xAI, designed for high-level reasoning, agentic behavior, and real-world task automation. It builds upon Grok 3’s architecture, but trains reasoning with 10× more compute and integrates tool use directly into its RLHF pipeline.

Technical Specification

Performance Benchmarks

• Context Window: 256,000 tokens
• Max Output: ~4,096 tokens
• Training Regime: 10× more RL compute than Grok 3
• Tool Use: Native, with strong multi-step support
  

Performance Metrics

• SOTA on ARC-AGI-2: 15.9%
• AIME 2025: 76.9% accuracy
• Humanity’s Last Exam (HLE):
  • With tools: 44.4% overall, 50.7% on text-only section
  • Without tools: 25.4% (vs 21.6% Gemini 2.5 Pro)

Key Capabilities

• Multi-step reasoning across long contexts
• Native tool-use through real/synthetic environments
• Deterministic outputs (non-streamed)
• Planning with API execution
• Robust performance on AGI-style benchmarks

API Pricing

Input: 0–128k: $3.9; 128k+: $7.8

Output: 0–120–128k: $19.5; 128k+: $39

Code Samples

Comparison with Other Models

• vs. GPT‑4o: GPT‑4o leads in multimodality and web browsing. Grok 4 offers better reasoning performance and tool integration in AGI-style tasks.‍
• vs. Claude 4 Opus: Claude 4 excels in language safety and alignment. Grok 4 outperforms on ARC-AGI-2 (15.9% vs 8.6%) and HLE, especially in tool-enabled setups.‍
• vs. Gemini 2.5 Pro: Gemini is strong in speed and instruction following. Grok 4 surpasses in zero-shot reasoning and planning (HLE 25.4% vs 21.6% without tools).
• vs. Grok 3: Grok 4 is a major upgrade over Grok 3, trained with 10× more RL compute and native tool-use instruction. It achieves 25.4% on Humanity’s Last Exam without tools (vs. Grok 3’s ~14.7%), and delivers better multi-step reasoning and factual recall.
  

Limitations

• Text-only (no vision/audio support as of Grok 4)
• Tool use not compositional (sequential only)
• Closed-weight model
• Seed determinism may be unreliable in streaming
• No public inference locally or offline

API Integration

Accessible via AI/ML API. Sign up here.

• Academic Benchmarking: High performance in math, logic, and abstract reasoning tasks.
• Long-Context Summarization: Handles documents and threads with extreme context.
• Research Prototyping: Ideal for technical exploration and agent design.
• Competitive Analysis: For evaluation against frontier reasoning models.