Released 23 days after Grok 4.20 Non-Reasoning · All xAI releases
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.
Call Grok 4.3 on Opper with the OpenAI SDK. Sign up without a credit card. Get started
Grok 4.3 runs on 5 different routes through the Opper gateway. Compare residency, zero data retention and training posture at a glance, with full data-handling detail per route below.
Grok 4.3 runs on 2 independently monitored routes through the Opper gateway. A direct integration leaves you on one of them, the gateway serves whichever is healthy.
Measured over the last 30 days from each provider's official status feed via StatusGator. Refreshed hourly. See uptime for every provider Opper monitors.
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 with abuse monitoring: nothing is logged or used for training; content flagged by abuse monitoring is held for review. No training on customer data. GLOBAL; SCCs; DPA available.
Zero data retention: nothing is logged, held for abuse monitoring or used for training. No training on customer data. US; SCCs; DPA available.
Zero data retention: nothing is logged, held for abuse monitoring or used for training. No training on customer data. EU; DPA available.
Zero data retention with abuse monitoring: prompts and outputs are kept for up to 30 days for abuse monitoring only, and are not used for training. No training on customer data. US; SCCs; DPA available.
Zero data retention with abuse monitoring: prompts and outputs are kept for up to 30 days for abuse monitoring only, and are not used for training. No training on customer data. EU; DPA available.
Independent benchmark scores — 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. Opper is drop-in compatible with the OpenAI, Anthropic and Google AI SDKs.
Grok 4.3 is a premium model on Opper. Sign up needs no credit card: you get an API key straight away and the free models work in the playground and the API. Add a card to use premium models, pay-as-you-go with no minimum.
Copy this and paste it into a coding agent like Claude Code, Cursor or Codex 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: "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.
