Musk’s xAI launches Grok 4.1 with lower hallucination rate on web and apps – no API access (yet)

In what appeared to be an attempt to soak up some of Google’s attention ahead of the launch of its new flagship AI model Gemini 3 – now recorded as the world’s most powerful LLM by several independent reviewers – Elon Musk’s rival AI startup xAI last night unveiled its new big language model, Grok 4.1.

The model is now available for consumer use on Grok.com, social network xAI has also commendably published a white paper on its assessments and including a little bit about the training process here.

According to public benchmarks, Grok 4.1 rose to the top of the rankings, outperforming competing models from Anthropic, OpenAI and Google – at least Google’s pre-Gemini 3 model (Gemini 2.5 Pro). It builds on the success of xAI’s Grok-4 Fast, which VentureBeat covered favorably shortly after its September 2025 release.

However, enterprise developers looking to integrate the new and improved Grok 4.1 model into production environments will face a major constraint: it is not yet available through xAI’s public API.

Despite its high benchmarks, Grok 4.1 remains confined to xAI’s consumer interfaces, with no announced timeline for API exposure. Currently, only older models, including Grok 4 Fast (reasoning and non-reasoning variants), Grok 4 0709, and existing models such as Grok 3, Grok 3 Mini, and Grok 2 Vision, are available for programmatic use via the xAI development API. These support up to 2 million context tokens, with token pricing ranging from $0.20 to $3.00 per million depending on configuration.

For now, this limits Grok 4.1’s usefulness in enterprise workflows that rely on back-end integration, optimized agent pipelines, or scalable internal tools. While consumer deployment positions Grok 4.1 as the highest performing LLM in xAI’s portfolio, production deployments in enterprise environments remain pending.

Model design and deployment strategy

Grok 4.1 arrives in two configurations: a fast, low-latency response mode for immediate responses, and a “think” mode that engages in multi-step reasoning before producing a result.

Both versions are available to end users and are selectable via the model selector in xAI applications.

The two configurations differ not only in latency, but also in the depth with which the model processes prompts. Grok 4.1 Thinking leverages the internal planning and deliberation mechanisms, while the standard version prioritizes speed. Despite the difference in architecture, both performed better than all competing models in blind preference testing and benchmark testing.

Leader in the field of human and expert evaluation

In the LMArena Text Arena rankings, Grok 4.1 Thinking briefly held the top spot with a normalized Elo score of 1483 — then was dethroned a few hours later with Google’s release of Gemini 3 and its incredible Elo score of 1501.

The unreflected version of Grok 4.1 also ranks well on the index, at 1465.

These scores place Grok 4.1 above Google’s Gemini 2.5 Pro, Anthropic’s Claude 4.5 series, and OpenAI’s GPT-4.5 preview.

In creative writing, Grok 4.1 ranks second behind Polaris Alpha (an early variant of GPT-5.1), with the “thinking” model scoring 1,721.9 on the Creative Writing v3 benchmark. This represents an improvement of around 600 points over previous iterations of Grok.

Likewise, in the Arena Expert ranking, which brings together comments from professional evaluators, Grok 4.1 Thinking is again in the lead with a score of 1,510.

The gains are particularly notable given that Grok 4.1 was released just two months after Grok 4 Fast, highlighting xAI’s accelerated pace of development.

Fundamental improvements compared to previous generations

Technically, Grok 4.1 represents a significant leap in real-world usability. Visual capabilities, previously limited in Grok 4, have been upgraded to enable robust understanding of images and videos, including OCR-level graph analysis and text extraction. Multimodal reliability was an issue in previous versions and has now been resolved.

Token-level latency was reduced by approximately 28% while preserving reasoning depth.

In long context tasks, Grok 4.1 maintains consistent output up to 1 million tokens, improving Grok 4’s tendency to degrade beyond the 300,000 token mark.

xAI also improved the model’s tool orchestration capabilities. Grok 4.1 can now schedule and run multiple external tools in parallel, reducing the number of interaction cycles required to perform multi-step queries.

According to internal test logs, some search tasks that previously required four steps can now be completed in one or two.

Other alignment improvements include better truth calibration (reducing the tendency to cover up or soften politically sensitive output) and more natural, human-like prosody in voice mode, with support for different speaking styles and accents.

Security and robustness against the adversary

As part of its risk management framework, xAI has evaluated Grok 4.1 for refusal behavior, hallucination resistance, sycophancy, and dual-use safety.

The hallucination rate in no-reasoning mode dropped from 12.09% in Grok 4 Fast to just 4.22%, an improvement of about 65%.

The model also scored 2.97% on FActScore, an evidence-based benchmark for quality assurance, up from 9.89% in previous versions.

In the area of ​​adversarial robustness, Grok 4.1 was tested with rapid injection attacks, jailbreak prompts, and sensitive chemical and biological queries.

Security filters showed low false negative rates, especially for restricted chemical knowledge (0.00%) and restricted biological queries (0.03%).

The model’s ability to resist manipulation in persuasion tests, such as MakeMeSay, also appears strong: it recorded a 0% success rate as an attacker.

Limited access to businesses via API

Despite these gains, Grok 4.1 remains unavailable to professional users via the xAI API. According to the company’s public documentation, the latest models available to developers are Grok 4 Fast (reasoning and non-reasoning variants), each supporting up to 2 million context tokens at price points ranging from $0.20 to $0.50 per million tokens. These are backed by a throughput limit of 4 million tokens per minute and a throughput cap of 480 requests per minute (RPM).

In contrast, Grok 4.1 is only accessible through xAI:X’s consumer properties, Grok.com, and mobile apps. This means that organizations cannot yet deploy Grok 4.1 through refined internal workflows, multi-agent chains, or real-time product integrations.

Industry reception and next steps

This version attracted numerous comments from the public and the industry. Elon Musk, founder of xAI, posted a brief endorsement, calling it a “great model” and congratulating the team. Leading AI platforms have praised the progress in terms of usability and linguistic nuances.

For corporate clients, however, the picture is more mixed. Grok 4.1’s performance represents a major step forward for general and creative tasks, but until API access is enabled, it will remain a consumer-facing product with limited enterprise applicability.

As competing models from OpenAI, Google, and Anthropic continue to evolve, xAI’s next strategic move may depend on when and how it opens up Grok 4.1 to external developers.