Isbot

Isbot is a small open-source JavaScript library that detects whether a given user agent string belongs to a bot or automated crawler. It is designed to be lightweight and fast, suitable for use in Node.js servers and browser-based applications. The library provides a simple interface to determine if a request originates from a bot, helping developers tailor responses, collect accurate analytics, or apply bot-specific logic.

The core idea behind isbot is a curated list of bot identifiers and regular expressions that match known crawlers and automation tools. By comparing a user agent string against this dataset, it can identify a wide range of bots, including major search engine crawlers as well as more obscure automation tools. While not perfect, it aims to offer a practical balance between accuracy and performance for common web use cases.

Usage is typically straightforward: a function is called with a user agent string, and a boolean result indicates whether the string is associated with a bot. This makes it convenient to integrate into request handling in server frameworks or client-side code that needs to distinguish automated traffic from human visitors. The library is often used to adjust content delivery, route crawlers differently, or inform analytics and logging.

Isbot is available on the npm registry and maintained as open-source software. It is commonly released under an permissive license and hosted in a public repository, where contributors update the bot patterns and improve performance. Because user agents can be spoofed, isbot complements but does not replace broader bot-detection and access-control strategies.