Published on 2025-08-07T06:18:08Z

SimplePie bot

The SimplePie bot is not a bot from a single service but a user-agent for the SimplePie PHP library, an open-source tool for parsing RSS and Atom feeds. Its presence in your logs means a third-party website or application built with this library is fetching your content feed. This is a common and legitimate activity for websites that provide syndicated content and helps distribute your content to a wider audience of feed readers and aggregators.

What is the SimplePie bot?

SimplePie is a popular open-source PHP library that allows developers to parse RSS and Atom feeds. It is a feed parser, not a traditional web crawler, though it does make HTTP requests to fetch feed content. When an application using this library accesses your site, it may identify itself with a user-agent string like SimplePie/ [VERSION] (Feed Parser; http://simplepie.org; ...). This identifier is customizable, but the default provides transparency. The library is designed to handle the complexities of various feed formats.

Why is a SimplePie bot crawling my site?

A SimplePie bot is visiting your site because someone has configured an application to fetch and parse your site's RSS or Atom feed. This is a legitimate activity from users who want to follow your content through feed readers or content aggregators. The bot specifically targets your feed URLs, not your entire website. The frequency of requests is determined by the configuration of the third-party application using the library.

What is the purpose of a SimplePie bot?

The purpose of the SimplePie library is to make it easier for developers to work with syndicated feeds. Applications using SimplePie include feed readers, content curation platforms, and websites that display news from multiple sources. For website owners who publish feeds, applications built with SimplePie help distribute your content to a wider audience. This can reach readers who prefer to use feed readers rather than visiting your site directly, helping to maintain an engaged readership.

How do I block a SimplePie bot?

To prevent applications using the SimplePie library from fetching your feeds, you can add a disallow rule to your robots.txt file. Note that this will stop users of these applications from receiving your content updates.

To block the default user-agent, add the following lines to your robots.txt file:

User-agent: SimplePie
Disallow: /

How to verify the authenticity of the user-agent operated by ?

Reverse IP lookup technique

To verify user-agent authenticity, you can use host linux command two times with the IP address of the requester.
  1. > host IPAddressOfRequest
    This command returns the reverse lookup hostname (e.g., 4.4.8.8.in-addr.arpa.). 
  2. > host ReverseDNSFromTheOutputOfFirstRequest
If the output matches the original IP address and the domain is associated with a trusted operator (e.g., ), the user-agent can be considered legitimate.

IP list lookup technique

Some operators provide a public list of IP addresses used by their crawlers. This list can be cross-referenced to verify a user-agent's authenticity. However, both operators and website owners may find it challenging to maintain an up-to-date list, so use this method with caution and in conjunction with other verification techniques.