Overview
Grok 4.3 is xAI's Grok flagship for the April–June 2026 window, released to the API on April 30, 2026 and succeeded by Grok 4.5 on July 9, 2026. It was positioned by xAI at launch as 'the most intelligent and fastest model we've built' and served as the default recommendation for general chat, reasoning, and coding tasks on the platform.
The model offers a 1 million token context window and accepts text and image inputs, generating text outputs. xAI's API uses the OpenAI SDK dialect, so existing GPT-based clients can typically switch by changing the base URL and model name.
Grok 4.3 emphasizes improved agentic performance and lower pricing versus the prior Grok 4.20 line — Artificial Analysis reported roughly 40% lower input and 60% lower output costs. It is distinct from grok-build-0.1, a separate early-access model trained specifically for agentic coding.
| Released | 2026-04-30 |
|---|---|
| License | Proprietary |
| Weights | API only |
| Context | 1M |
| Modalities | Text, Vision |
| Status | Available |
Benchmarks
This model's scores
Scores on a 0–100 scale (25-point gridlines); higher is better. Each benchmark links to its published source.
Pricing
| Input | $1.25 / 1M tokens |
|---|---|
| Output | $2.50 / 1M tokens |
Strengths
- 1 million token context window for long-document and large-codebase work
- Reasoning-first design with strong agentic tool-calling
- OpenAI-SDK-compatible API for easy migration
- Competitive pricing at $1.25 / $2.50 per 1M tokens
- Native image input alongside text
Best for
- Long-context document and codebase analysis
- Agentic workflows with tool calling and structured outputs
- General reasoning, research, and coding assistance
- Multimodal tasks combining text and image input
How to access
| Provider | Model ID |
|---|---|
| xAI ↗ | grok-4.3 |
Grok (flagship) — every version
The full lineage of the Grok (flagship) line, newest first. Every version has its own page — click any to compare specs, benchmarks and pricing.
FAQ
Where does Grok 4.3 sit in xAI's Grok lineup?
Grok 4.3 was xAI's Grok flagship from April 30 to July 9, 2026, when it was succeeded by Grok 4.5. xAI described it at launch as the most intelligent and fastest model it had built and recommended it as the default for general chat, reasoning, and coding. It remains available in the API and is separate from grok-build-0.1, an early-access agentic coding model.
What is the difference between Grok 4.3 and grok-build-0.1?
Grok 4.3 is the general-purpose flagship with a 1M-token context window for chat, reasoning, and coding. grok-build-0.1 is a separate, faster model in early access, trained specifically for agentic coding, with a smaller 256K context window and lower pricing of $1.00 input and $2.00 output per 1M tokens.
How much does Grok 4.3 cost?
Grok 4.3 is priced at $1.25 per 1M input tokens and $2.50 per 1M output tokens, per Artificial Analysis. This reflects roughly 40% lower input and 60% lower output pricing than the prior Grok 4.20 line, making the flagship significantly cheaper while improving agentic performance.
What context window does Grok 4.3 support?
Grok 4.3 supports a 1 million token context window, suitable for long documents and large codebases. It accepts text and image inputs and produces text output, and is accessible through xAI's OpenAI-SDK-compatible API for straightforward migration from GPT-based clients.