xAI’s Grok 4.3 is now generally available on Amazon Bedrock, providing teams with a model that reasons reliably over long inputs. The model, which is part of Amazon Bedrock’s growing provider ecosystem, offers strong tool use and instruction following for building agents, along with token efficiency for high-volume inference. It accepts both text and image input, and features a 1 million token context window for handling long documents and multi-turn sessions. Grok 4.3 runs on Mantle, the next-generation inference engine in Amazon Bedrock, and is accessible through OpenAI-compatible APIs.
According to xAI, Grok 4.3 is built for enterprise work where accuracy matters. On its own benchmarks at the time of the model launch, xAI reports it outperforms various industry benchmarks. Grok 4.3 ranked #1 on the Artificial Analysis Omniscience benchmark with the lowest hallucination rate among the frontier models it compared. It also placed #1 on the Artificial Analysis Tau2 Telecom benchmark for tool calling in customer support scenarios, and #1 on the Vals AI Case Law and Corporate Finance benchmarks for document understanding. xAI also places the model on the intelligence-versus-cost Pareto frontier, which it describes as 2 to 10 times more intelligence per dollar than other frontier models.
The model allows users to control how much the model thinks before answering through an effort level on each request. Users can configure the effort level (none, low, medium, and high) per request and let one model serve the full range of work. A classification call can run at none effort to keep latency low, while a contract analysis or case law task can run at high when depth matters more than response time. Grok 4.3 accepts text and image input and returns text, and its 1 million token context window leaves room for long documents and extended multi-turn sessions. The model handles tool calling and instruction following well, which is what makes it practical for agents that depend on function calls to take action.
Source: awsml
