Profile – (Ping Server)


Launched: 1999

What is it? was the first blogging ping service and remains the largest.

What is a ping service?

A ping service is a server that takes “pings” from blogs (and other sources). The purpose of the ping is to notify the ping server that the source has added new content. This is aggregated with other pings and, if the ping server is open, the data becomes available to third parties. The third parties are able to access the URI of the source and the time of the ping.

Ping services are not discussed very often. There’s not much to look at (the action is in the xml data), and to date they haven’t charged for their services. However, ping servers are the backbone of the blogosphere infrastructure and are a crucially important piece of the real-time web.

Here’s why: Ping servers sit between search engines and blogs. Without ping servers, search engines like feedster, technorati and pubsub would not know if and when blogs and other content sources updated. They would regularly have to index these sites to find out if they’ve updated. With over 10,000,000 blogs, re-indexing every hour would be a massive undertaking – every few minutes, impossible. Instead, they re-index only when a source notifies the ping server that it has updated. It is a much more efficient way for the real-time web to keep “real-time” with only a few minute delay between posting and indexing.

There are many ping servers today (see links below for lists), but was the first and is by far the largest, as it is built into nearly all blogging software.

Dave Winer created in 1999 as a service to index weblogs. He re-launched it as a ping server in November 2001 (see also here) as blogs started to grow beyond the point where it was feasible to re-index them regularly.

Today is receiving over 1,000,000 pings per day (link). has an open back end and allows anyone to access its data.


To ping, a site sends a a simple XML-RPC message to, port 80, path /RPC2. that includes the feed name (name of blog or other source) and the URL.

To access ping data, third parties can access two versions: shows data from the last hour, and
shows data from the last five minutes.

For more complete information, see the XML-RPC Interface post here. is a podcasting ping service. It is very much like, but it includes additional data as well:

– size of podcast
– xml feed of podcast
– number of clicks on link (a ranking or popularity feature)

Pinging and accessing data is similar to the normal ping service.

Dave Winer discussing the transition in 2001
Lists of Ping servers: Chris Abraham,,

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