Use Grok 4.3 (xAI) for Free

Grok 4.3 (xAI) is an AI model released 2026-04 by xAI, a leading organization in large language model research. Grok 4.3 by xAI — highly capable general model with real-time information access and exceptional reasoning performance. With ~314B MoE (Grok 4 family, ~52B active params) and a 1M tokens context window, Grok 4.3 (xAI) is designed to excel across a range of demanding tasks — from software engineering and mathematical problem-solving to multilingual content generation and long-document analysis.

Grok 4.3 (xAI) employs a Mixture-of-Experts (MoE) architecture with ~314B MoE (Grok 4 family, ~52B active params). In a MoE design, only a subset of "expert" sub-networks activates for each token during inference — Grok 4.3 (xAI) has ~314B MoE (Grok 4 family, ~52B active params) total parameters but uses only a fraction per token. This allows the model to store significantly more learned knowledge than a comparably-priced dense model. MoE architectures have proven effective at reaching frontier-level capability while keeping serving costs manageable — a key reason Grok 4.3 (xAI) can be offered at the scale that platforms like LITHOVEX AI make possible.

As of 2026-10-16, Grok 4.3 (xAI) by xAI demonstrates measurable performance on standard AI evaluation benchmarks. On AIME 2025 — which tests advanced competition mathematics at the highest US high school level — it achieves 91.8%. For software engineering tasks, Grok 4.3 (xAI) scores 95.1% on HumanEval, which tests ability to write correct functions from docstrings. In mathematical reasoning, Grok 4.3 (xAI) records 91.8% on AIME 2025. Across all 4 benchmarks tracked, the model shows consistent capability in its primary task domains. These scores place Grok 4.3 (xAI) — at ~314B MoE (Grok 4 family, ~52B active params) of parameters — in a competitive position within its model class. Note that benchmark scores reflect controlled evaluation conditions; real-world performance varies by task, prompt design, and domain specificity.

The primary strengths of Grok 4.3 (xAI) are: xAI's frontier reasoning model — top-tier performance on STEM, mathematics, and advanced scientific tasks; Real-time X (Twitter) and web access for up-to-the-minute factual grounding on current events; Grok 4-class intelligence: competitive with leading frontier models on math and science benchmarks; Strong at multi-step reasoning, hypothesis generation, and technical analysis. These make it particularly well-suited for Advanced scientific research requiring current literature and real-time data, Mathematical problem solving and competition-level reasoning, Current events analysis combining AI reasoning with live X data, Complex software engineering and system design projects. Users working on complex, multi-step problems benefit most from Grok 4.3 (xAI)'s ability to maintain coherence across long inputs and produce structured, verifiable outputs.

Like all current AI systems, Grok 4.3 (xAI) has limitations: Proprietary xAI model — no self-hosting; API access required for high-volume usage; Real-time web access can occasionally surface unverified information. For production deployments, validating outputs against authoritative sources — especially for domain-specific or time-sensitive information — remains best practice. xAI continues to improve Grok 4.3 (xAI) through ongoing research.

Grok 4.3 (xAI) is available on LITHOVEX AI with a free account. Unlike direct API access — which requires billing setup, API key management, and per-token charges — LITHOVEX AI provides a seamless browser interface with no setup required, making Grok 4.3 (xAI) accessible to students, researchers, developers, and early-stage teams globally.

As of 2026-10-16, Grok 4.3 (xAI) by xAI demonstrates measurable performance on standard AI evaluation benchmarks. On AIME 2025 — which tests advanced competition mathematics at the highest US high school level — it achieves 91.8%. For software engineering tasks, Grok 4.3 (xAI) scores 95.1% on HumanEval, which tests ability to write correct functions from docstrings. In mathematical reasoning, Grok 4.3 (xAI) records 91.8% on AIME 2025. Across all 4 benchmarks tracked, the model shows consistent capability in its primary task domains. These scores place Grok 4.3 (xAI) — at ~314B MoE (Grok 4 family, ~52B active params) of parameters — in a competitive position within its model class. Note that benchmark scores reflect controlled evaluation conditions; real-world performance varies by task, prompt design, and domain specificity.

Proprietary xAI Grok transformer — Mixture-of-Experts, frontier-class reasoning with real-time X/web grounding

The training pipeline for Grok 4.3 (xAI) involves multiple stages: large-scale pretraining on diverse multilingual text and code corpora to develop broad world knowledge, followed by supervised fine-tuning on instruction-response pairs, and alignment techniques such as RLHF or DPO. Each stage refines the model's helpfulness, accuracy, and safety.

Inference efficiency: Grok 4.3 (xAI) at ~314B MoE (Grok 4 family, ~52B active params) is designed to deliver quality outputs at practical serving speeds. Its 1M tokens context window enables processing entire documents, multi-file codebases, and extended conversation histories — particularly valuable for contract review, technical documentation analysis, and codebase-level AI assistance.

Getting started with Grok 4.3 (xAI) on LITHOVEX AI takes under two minutes. Follow these steps:

For best results with Grok 4.3 (xAI): provide specific, context-rich prompts; include examples when generating code; specify output format when structure matters; break complex tasks into focused sub-questions. Since Grok 4.3 (xAI) supports extended reasoning, prompting it to "think step by step" or "show your reasoning" activates deeper chain-of-thought analysis for math, logic, and complex problems.

xAI is an AI company founded by Elon Musk in March 2023, headquartered in Palo Alto, California. Musk founded xAI after departing OpenAI's board, with an explicit mission to "understand the true nature of the universe" through AI. The company operates with full support from X (formerly Twitter) — xAI's Grok models have real-time access to X's data streams, enabling them to reference current events that other AI models cannot. Grok has been rapidly iterated — Grok 1 in 2023, Grok 2 in 2024, and Grok 3 in 2025 — with each generation making substantial benchmark gains. The Grok 3 series achieved top-10 performance on major coding and reasoning benchmarks. xAI raised a $6 billion Series B in 2024, one of the largest single funding rounds in AI history. The company positions itself as a "maximally truth-seeking" AI, explicitly designed to handle controversial topics that more conservatively tuned models avoid. As of 2026, xAI employs hundreds of researchers and operates its own computing cluster "Colossus" — one of the world's largest GPU clusters.

Funding: $6B+ raised (including $6B Series C round)

Founded: 2023.

Visit the official xAI website →

Grok 4.3 (xAI) by xAI competes in a field with several strong alternatives. Below is a detailed side-by-side comparison against commonly listed alternatives, using benchmark data and capability profiles in the catalog.

Both Grok 4.3 (xAI) and the models above are available free on LITHOVEX AI — test them side by side on your real tasks before committing to a subscription with any provider.

Grok 4.3 serves the global market for real-time-aware AI. Its X/Twitter integration provides genuine current events awareness unavailable to most other AI models, making it uniquely valuable for researchers, journalists, and professionals tracking current news and global events.

Grok 4.3 (xAI) by xAI has the following version history and notable updates:

For the complete changelog and latest release notes, visit the official xAI model page.