grok-4-0709

grok-4-0709 is a frontier-tier reasoning model from xAI in the Grok 4 family. It performs extended internal chain-of-thought before producing a final answer, which improves accuracy on complex multi-step tasks at the cost of higher latency compared to standard non-reasoning models. It supports a 256K-token context window, vision inputs, function calling, and streaming. grok-4-0709 is a proprietary model available exclusively through xAI's API.

grok-4-0709 is priced at $3.00 per million input tokens and $15.00 per million output tokens. The 5:1 output-to-input ratio reflects the sequential cost of autoregressive generation; reasoning models tend to produce more output tokens per request because the internal reasoning trace is billed alongside the final answer. At a typical usage pattern of 1,000 input tokens and 500 output tokens per call, the cost is approximately $0.0105 per 1,000 API calls. xAI does not publish a prompt caching rate for this model, so repeated long contexts are billed at the standard $3.00/1M input rate.

The 256K-token context window is in the top tier for production models, enabling full-document analysis, large codebase understanding, and long multi-turn conversations without chunking. Maximum output is 131,072 tokens — sufficient for long-form content, detailed code files, and extended reports. Median latency (P50 time-to-first-token) is approximately 1,200ms, which is higher than non-reasoning models because the model must complete its reasoning trace before streaming begins. Throughput is approximately 70 tokens per second. grok-4-0709 is best suited to reasoning, coding, and chat workloads where reasoning depth matters more than response speed.