Grok 4.3 is xAI's reasoning flagship released April 2026, unifying reasoning, vision, and tool use into a single production model across a 1 million token context window. Reasoning is on by default for every request, with configurable effort levels so you can dial in the reasoning depth appropriate for each task. Native vision input enables multimodal analysis across text and images, while agentic support includes tool calling, structured outputs, and web search. The model targets reasoning-heavy workloads such as mathematical problem solving, code analysis, multi-step planning, and tasks where structured thinking improves answer quality. With an April 2026 release and a December 2025 knowledge cutoff, Grok 4.3 is xAI's answer to production-scale reasoning, balancing accuracy, latency, and the long context that modern agentic systems demand.
Grok 4.3 runs on 3 different routes through the Opper gateway. Compare residency, ZDR, and training posture at a glance โ full data-handling detail per route below.
Training posture across routes: No training on prompts by default.
Each route hosting Grok 4.3 has its own privacy posture, residency, and GDPR terms. Postures are maintained by Opper with a last-verification timestamp.
Zero data retention is available via Opper Enterprise contract. No training on customer data. US; SCCs; DPA available.
Zero data retention is available via Opper Enterprise contract. No training on customer data. US; SCCs; DPA available.
Zero data retention is available via Opper Enterprise contract. No training on customer data. EU; DPA available.
Independent benchmark scores โ composite indices for reasoning, coding, and math, plus individual eval scores where available.
Call Grok 4.3 through the Opper gateway with one API key. Let your coding agent set it up, or call it directly โ Opper is drop-in compatible with the OpenAI, Anthropic, and Google AI SDKs.
Copy this and paste it into your coding agent โ Claude Code, Cursor, Codex, and more โ and it'll wire up Opper for you.
import OpenAI from "openai";const client = new OpenAI({apiKey: process.env.OPPER_API_KEY,baseURL: "https://api.opper.ai/v3/compat",});const completion = await client.chat.completions.create({model: "xai/grok-4.3",messages: [{ role: "user", content: "Hello" }],});console.log(completion.choices[0].message.content);
Side-by-side on privacy, EU hosting, pricing, and benchmarks.
