JavaScript Links and Pagerank

[jdancing]

Now that Google follows and indexes JavaScript links, has anyone experimented with a JavaScript link campaign?

This seems to open the door to all kinds of widgets and contextual link techniques that are much more difficult using PHP/ASP generated HTML links.

The wheels are turning....

[martinibuster]

Indexing for discovery is one thing. Using the data to pass PageRank or influence ranking is something else.

[jdancing]

I got a very different impression after listening to this Matt Cutts video: [youtube.com...]

While on the topic of JavaScript links he suggests just like any other links "if your selling text links, just make sure those links don't flow pagerank". He even suggests using the nofollow on JavaScript links.

It would be and interesting experiment to create a new site and only link to it with JavaScript links from stong sites and see how quickly the site gets indexed and if "pagerank flows" to it.

[martinibuster]

He even suggests using the nofollow on JavaScript links.

That still falls short of saying JS links flow PR. Depends on the context in which it was said. It could only be a reference to stopping the JS links from being used for discovery.

I haven't listened to that but will later tonight after I've finished with my evening parental duties.

[FranticFish]

According to Vanessa Fox, Google passes anchor text and PR via certain Javascript links.

This statement was made as part of a big post made in May 2009 on SearchEngineLand (not linked to as not sure if it would be allowed) following the Google May 2009 I/O conference.

The way the article reads to me is that she's quoting an announcement made at the conference but I can't find anything in writing from Google on the subject.

[martinibuster]

I've read that essay [searchengineland.com] from last year and it's not clear. Here is the relevant quote from a Googler (with emphasis added):

Our onclick processing is becoming more widespread, but keep in mind it’s still an area where we’re constantly improving. We already detect many ads generated by onclick events.

To prevent PR [PageRank] flow, it remains a good practice to do things like have the onclick-generated links in an area that’s blocked from robots, or to use a url redirector that’s robots.txt disallow’d. Penalties for spam techniques have been and will continue to be enforced, but as you know, we work extremely hard to minimize false positives.

[FranticFish]

I've tested myself and Google crawls Javascript popup links.

<a href="javascript:;" onClick="window.open('pop.htm')">anchor text</a>

In this situation pop.htm was indexed, however anchor text (a unique two word gibberish phrase) was not passed.

As far as I remember onClick events in img tags do pass anchor text from the img alt tag. I've set up a test to check this.

If Google indexes content at the end of a link that cannot be reached any other way I'd say that means that PR is being passed. However when they announced in 2008 that they were crawling GET forms and indexing content discovered that way they mentioned that pages discovered wouldn't be seen to be part of a site's index allocation - which is based on PR.

[FranticFish]

Re: that article, this was the bit I was referring to:

As of today, they’re able execute JavaScript onClick events. They still recommend using progressive enhancement techniques, however, rather than to rely on Googlebot’s ability to extract from the JavaScript (not just for search engine purposes, but for accessibility reasons as well).

Googlebot is now able to construct much of the page and can access the onClick event contained in most tags. For now, if the onClick event calls a function that then constructs the URL, Googlebot can only interpret it if the function is part of the page (rather than in an external script).

Some examples of code that Googlebot can now execute include:

<div onclick="document.location.href='http://foo.com/'">
<tr onclick="myfunction('index.html')"><a href="#" monclick="myfunction()">new page</a>
<a href="javascript:void(0)" onclick="window.open('welcome.html')">open new window</a>

These links pass both anchor text and PageRank.

It's not explicitly stated, but that looks to me like a report of a statement given at the conference by a Googler.

[jdancing]

The possibility of being able to use JavaScript links for paid links opens all kinds of doors. I am not sure how I let this slip by me.

I'll be setting up a new domain and only have 10 to 15 JavaScript links going to it with a specific but easily rankable keyword phrase to see if; A) The page gets ranked at all for the keyword phrase and; B) Does the page eventually get PageRank.

[martinibuster]

These links pass both anchor text and PageRank. ...that looks to me like a report of a statement given at the conference by a Googler.

You're right, but it's not a direct quote. The statement itself looks like it's coming from Vanessa Fox herself, not a quote attributed to a specific Googler.

I searched all the Google blogs for a statement, as well as on the web for a direct quote of a Googler that confirms the year old statement by Vanessa Fox but there is nothing there.

I tried to find evidence to substantiate this rumor but I can't find anything.

[tedster]

At PubCon Austin in 2009 Matt Cutts told me that when Google can parse form and JavaScript links, they add a "virtual link" to their webgraph for the purposes of calculating PageRank and other link juice. At that time they were only parsing rather basic types, but were working to upgrade the capability.

This lines up with Matt's published recommendation that JavaScript redirects for paid links should pass through a script that robots are denied access to. His recommendation many years earlier was to use JavaScript because Google doesn't process it. Now the recommendation is also to block the script itself from googlebot spidering.

Since that time, I saw this in action for one case. A major business website came to me with a run-of-site JavaScript form as the only "link" to an important new page. That URL was indexed, ranking well and showed lots of TBPR.

Sorting out anchor text, trust and other possible link juice factors is more complex. I can't confirm or refute any of that.

Along these lines, I also had an emergency call last year from someone whose website had a penalty. Their widely distributed widget included an embedded js link to their website. When they removed that link from the widget and requested reconsideration, their rankings returned.

Just a couple of data points there. I can't point to anything Google officially published on the web to firm it up any further.

[edited by: tedster at 7:19 pm (utc) on May 23, 2010]

[martinibuster]

Hey thanks Ted. There is informal confirmation that JS passes PR.

[vanessafox]

Just wanted to clarify that my information about what Google said about JavaScript from Google I/O in 2009 came from a talk given by Maile Ohye (of Google) and a later followup with Google to confirm the details.

[tedster]

Here's something relevant on video from Matt Cutts [youtube.com].

[jdancing]

I set up a brand new test website and pointed about 10 JavaScript links to the the homepage on May 21. So far the page has not been indexed or cached. If I used standard HTML links I am positive the site would have at least been found and cached.

I'll let the experiment go a while longer just to make sure, but it seems if JS if followed it is the exception, not the norm.

[CainIV]

I've tested myself and Google crawls Javascript popup links. If Google indexes content at the end of a link that cannot be reached any other way I'd say that means that PR is being passed.

This statement is inaccurate. Google crawls nofollow links and finds content on the other side, but the link value itself is not added to the link graph and does not impact the link profile of the destination page, so assuming that because Google can find and even index content via a link does not conclude that the link passes pagerank.

[FranticFish]

You're right, I didn't mean that to be such an assertion. I sort of qualified it with the next sentence.

"However when they announced in 2008 that they were crawling GET forms and indexing content discovered that way they mentioned that pages discovered wouldn't be seen to be part of a site's index allocation - which is based on PR."

My Javascript test results are in. Google crawled a new page via an image link using onClick="window.open" but returns no results when I search for the unique two word phrase used as alt text. I left it an extra week to check and it's still the same. I'll try a text link as well.

[tkchinese]

I've a B2B and I'm displaying full detail product description on JS link at listing page.

Short descriptions which listed on listing page are index but full descriptions are not which display in JS popup?

How been full description will be index?

[jdancing]

Update Before this post gets closed: It has been almost 2 months that I set up a test webpage with nothing but javascript links to it. It still has not been cached or indexed. If most any of these javascript links were html links the site would definitely indexed.

There goes my plans of creating all kinds of dodads that inject free javascript links back to my sites :-)