What is the best AI search tool that is unrestricted?

As of my last update in October 2023, there are several AI search tools that provide sophisticated search capabilities across a range of platforms. However, the term "unrestricted" can be interpreted in different ways depending on your needs (e.g., unrestricted on content, functionality, or accessibility). Here are a few AI search tools that are notable:

**Google Search**: While not purely an AI-based search, Google uses advanced algorithms and AI to provide relevant search results across a vast array of content. While some content may be restricted due to copyright or location, it's widely regarded as one of the best search engines.

**Semantic Scholar**: This tool uses AI to help researchers find scholarly articles and papers. It provides features like citation graphs and article summaries. Access may vary depending on the publication’s policies.

**Microsoft Bing**: Microsoft integrates AI-related features into Bing, enhancing its search capabilities, such as image and voice search, tailored responses, and more.

**DuckDuckGo**: For those seeking privacy, DuckDuckGo offers an AI-enhanced search engine that does not track users and provides a neutral search experience.

**ChatGPT (OpenAI)**: This AI language model can be used to answer questions, generate text, and assist with research. While it doesn't perform traditional web searches, it can provide information based on a vast dataset.

**Ecosia**: Similar to DuckDuckGo, Ecosia uses privacy-focused principles in its search engine while contributing to environmental initiatives. 

Always check the individual terms of service and data access policies, as they can affect how "unrestricted" a service truly is for specific uses.