fanfilter is a free Chrome add-on developed by ea that provides an advanced filter for fanfiction.net. With this tool, users can customize their search on fanfiction.net by applying various filters to find the stories they are interested in.

The add-on allows users to search for stories based on specific keywords. Users can use the "needle => contain needle" filter to search for stories that contain a particular word or phrase. Additionally, the "~needleA ~needleB => is needleA or needleB" filter allows users to search for stories that contain either needleA or needleB.

Users can also exclude certain keywords from their search results using the "-needle => doesn't contain needle" filter. This can help users filter out stories that are not relevant to their interests.

fanfilter also provides filters for specific characters, ratings, pairings, favorites, publication date, number of reviews, word count, update frequency, genres, completion status, fandoms, language, and sorting options. These filters allow users to narrow down their search results and find stories that meet their specific criteria.

Overall, fanfilter is a valuable tool for users of fanfiction.net who want to have more control over their search results. It offers a wide range of filters to help users find the stories they are looking for, making the search process more efficient and enjoyable.