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Site Errors Breakdown

agosto 30

Webmaster level: All

Today we’re announcing more detailed Site Error information in Webmaster Tools. This information is useful when looking for the source of your Site Errors. For example, if your site suffers from server connectivity problems, your server may simply be misconfigured; then again, it could also be completely unavailable!  Since each Site Error (DNS, server connectivity, and robots.txt fetch) is comprised of several unique issues, we’ve broken down each category into more specific errors to provide you with a better analysis of your site’s health.

Site Errors will display statistics for each of your site-wide crawl errors from the past 90 days.  In addition, it will show the failure rates for any category-specific errors that have been affecting your site.

If you’re not sure what a particular error means, you can read a short description of it by hovering over its entry in the legend.  You can find more detailed information by following the “More info” link in the tooltip.

We hope that these changes will make Site Errors even more informative and helpful in keeping your site in tip-top shape.  If you have any questions or suggestions, please let us know through the Webmaster Tools Help Forum.

Written by Cesar Cuenca and Tiffany Wang, Webmaster Tools Interns

Search Queries Alerts in Webmaster Tools

agosto 21
Webmaster level: All

We know many of you check Webmaster Tools daily (thank you!), but not everybody has the time to monitor the health of their site 24/7. It can be time consuming to analyze all the data and identify the most important issues. To make it a little bit easier we’ve been incorporating alerts into Webmaster Tools. We process the data for your site and try to detect the events that could be most interesting for you. Recently we rolled out alerts for Crawl Errors and today we’re introducing  alerts for Search Queries data.

The Search Queries feature in Webmaster Tools shows, among other things, impressions and clicks for your top pages over time. For most sites, these numbers follow regular patterns, so when sudden spikes or drops occur, it can make sense to look into what caused them. Some changes are due to differing demand for your content, other times they may be due to technical issues that need to be resolved, such as broken redirects. For example, a steady stream of clicks which suddenly drops to zero is probably worth investigating.

The alerts look like this:

We’re still working on the sensitivity threshold of the messages and welcome your feedback in our help forums. We hope the new alerts will be useful. Don’t forget to sign up for email forwarding to receive them in your inbox.

Posted by , Tech Lead, Webmaster Tools

Configuring URL Parameters in Webmaster Tools

agosto 14

Webmaster Level: Intermediate to Advanced

We recently filmed a video (with slides available) to provide more information about the URL Parameters feature in Webmaster Tools. The URL Parameters feature is designed for webmasters who want to help Google crawl their site more efficiently, and who manage a site with — you guessed it — URL parameters! To be eligible for this feature, the URL parameters must be configured in key/value pairs like item=swedish-fish or category=gummy-candy in the URL

Guidance for common cases when configuring URL Parameters. Music in the background masks the ongoing pounding of my neighbor’s construction!

URL Parameter settings are powerful. By telling us how your parameters behave and the recommended action for Googlebot, you can improve your site’s crawl efficiency. On the other hand, if configured incorrectly, you may accidentally recommend that Google ignore important pages, resulting in those pages no longer being available in search results. (There’s an example provided in our improved Help Center article.) So please take care when adjusting URL Parameters settings, and be sure that the actions you recommend for Googlebot make sense across your entire site.

Written by Maile Ohye, Developer Programs Tech Lead

Website testing & Google search

agosto 9

Webmaster level: Advanced

We’ve gotten several questions recently about whether website testing—such as A/B or multivariate testing—affects a site’s performance in search results. We’re glad you’re asking, because we’re glad you’re testing! A/B and multivariate testing are great ways of making sure that what you’re offering really appeals to your users.

Before we dig into the implications for search, a brief primer:
Website testing is when you try out different versions of your website (or a part of your website), and collect data about how users react to each version. You use software to track which version causes users to do-what-you-want-them-to-do most often: which one results in the most purchases, or the most email signups, or whatever you’re testing for. After the test is finished you can update your website to use the “winner” of the test—the most effective content.

A/B testing is when you run a test by creating multiple versions of a page, each with its own URL. When users try to access the original URL, you redirect some of them to each of the variation URLs and then compare users’ behaviour to see which page is most effective.

Multivariate testing is when you use software to change differents parts of your website on the fly. You can test changes to multiple parts of a page—say, the heading, a photo, and the ‘Add to Cart’ button—and the software will show variations of each of these sections to users in different combinations and then statistically analyze which variations are the most effective. Only one URL is involved; the variations are inserted dynamically on the page.

So how does this affect what Googlebot sees on your site? Will serving different content variants change how your site ranks? Below are some guidelines for running an effective test with minimal impact on your site’s search performance.

  • No cloaking.
    Cloaking—showing one set of content to humans, and a different set to Googlebot—is against our Webmaster Guidelines, whether you’re running a test or not. Make sure that you’re not deciding whether to serve the test, or which content variant to serve, based on user-agent. An example of this would be always serving the original content when you see the user-agent “Googlebot.” Remember that infringing our Guidelines can get your site demoted or removed from Google search results—probably not the desired outcome of your test.
  • Use rel=“canonical”.
    If you’re running an A/B test with multiple URLs, you can use the rel=“canonical” link attribute on all of your alternate URLs to indicate that the original URL is the preferred version. We recommend using rel=“canonical” rather than a noindex meta tag because it more closely matches your intent in this situation. Let’s say you were testing variations of your homepage; you don’t want search engines to not index your homepage, you just want them to understand that all the test URLs are close duplicates or variations on the original URL and should be grouped as such, with the original URL as the canonical. Using noindex rather than rel=“canonical” in such a situation can sometimes have unexpected effects (e.g., if for some reason we choose one of the variant URLs as the canonical, the “original” URL might also get dropped from the index since it would get treated as a duplicate).
  • Use 302s, not 301s.
    If you’re running an A/B test that redirects users from the original URL to a variation URL, use a 302 (temporary) redirect, not a 301 (permanent) redirect. This tells search engines that this redirect is temporary—it will only be in place as long as you’re running the experiment—and that they should keep the original URL in their index rather than replacing it with the target of the redirect (the test page). JavaScript-based redirects are also fine.
  • Only run the experiment as long as necessary.
    The amount of time required for a reliable test will vary depending on factors like your conversion rates, and how much traffic your website gets; a good testing tool should tell you when you’ve gathered enough data to draw a reliable conclusion. Once you’ve concluded the test, you should update your site with the desired content variation(s) and remove all elements of the test as soon as possible, such as alternate URLs or testing scripts and markup. If we discover a site running an experiment for an unnecessarily long time, we may interpret this as an attempt to deceive search engines and take action accordingly. This is especially true if you’re serving one content variant to a large percentage of your users.

The recommendations above should result in your tests having little or no impact on your site in search results. However, depending on what types of content you’re testing, it may not even matter much if Googlebot crawls or indexes some of your content variations while you’re testing. Small changes, such as the size, color, or placement of a button or image, or the text of your “call to action” (“Add to cart” vs. “Buy now!”), can have a surprising impact on users’ interactions with your webpage, but will often have little or no impact on that page’s search result snippet or ranking. In addition, if we crawl your site often enough to detect and index your experiment, we’ll probably index the eventual updates you make to your site fairly quickly after you’ve concluded the experiment.

To learn more about website testing, check out these articles on Content Experiments, our free testing tool in Google Analytics. You can also ask questions about website testing in the Analytics Help Forum, or about search impact in the Webmaster Help Forum.

Posted by , Webmaster Trends Analyst

Domain verification using CNAME records

agosto 2

Webmaster Level: all

In order to use Google services like Webmaster Tools and Google Apps you must verify that you own the site or domain. One way you can do this is by creating a DNS TXT record to prove your ownership of the domain. Now you can also use DNS CNAME records to verify ownership of your domains. This is a new domain verification option for users that are not able to create DNS TXT records for their domains.

For example, if you own the domain, you can verify your ownership of the domain by creating a DNS CNAME record as follows.

  1. Add the domain to your account either in Webmaster Tools or directly on the Verification Home page.

  2. Select the Domain Name Provider method of verification, then select your domain name provider that manages your DNS records or “Other” if your provider is not on this list.

  3. Based on your selection you may either see the instructions to set a CNAME record or see a link to the option Add a CNAME record. Follow the instructions to add the specified CNAME record to your domain’s DNS configuration.

  4. Click the Verify button.

When you click Verify, Google will check for the CNAME record and if everything works you will be added as a verified owner of the domain. Using this method automatically verifies you as the owner of all websites on this domain. For example, when you verify your ownership of, you are automatically verified as an owner of as well as subdomains such as

Sometimes DNS records take a while to make their way across the Internet. If we don’t find the record immediately, we’ll check for it periodically and when we find the record we’ll make you a verified owner. To maintain your verification status don’t remove the record, even after verification succeeds.

If you don’t have access to your DNS configuration at your domain name provider you can continue to use any of the other verification methods, such as the HTML file, the meta tag or Google Analytics tag in order to verify that you own a site.

If you have any questions please let us know via our Webmaster Help forum.

Posted by Pooja Wagh, Software Engineer

Introducing the Structured Data Dashboard

agosto 1

Webmaster level: All

Structured data is becoming an increasingly important part of the web ecosystem. Google makes use of structured data in a number of ways including rich snippets which allow websites to highlight specific types of content in search results. Websites participate by marking up their content using industry-standard formats and schemas.

To provide webmasters with greater visibility into the structured data that Google knows about for their website, we’re introducing today a new feature in Webmaster Tools – the Structured Data Dashboard. The Structured Data Dashboard has three views: site, item type and page-level.

Site-level view

At the top level, the Structured Data Dashboard, which is under Optimization, aggregates this data (by root item type and vocabulary schema).  Root item type means an item that is not an attribute of another on the same page.  For example, the site below has about 2 million Schema.Org annotations for Books (“”)

Itemtype-level view

It also provides per-page details for each item type, as seen below:

Google parses and stores a fixed number of pages for each site and item type. They are stored in decreasing order by the time in which they were crawled. We also keep all their structured data markup. For certain item types we also provide specialized preview columns as seen in this example below (e.g. “Name” is specific to Product).

The default sort order is such that it would facilitate inspection of the most recently added Structured Data.

Page-level view

Last but not least, we have a details page showing all attributes of every item type on the given page (as well as a link to the Rich Snippet testing tool for the page in question).

Webmasters can use the Structured Data Dashboard to verify that Google is picking up new markup, as well as to detect problems with existing markup, for example monitor potential changes in instance counts during site redesigns.

Posted by Thomas Biggs & Andrei Pascovici, Webmaster Tools Team

New notifications about inbound links

julio 28

Webmaster level: Advanced

Lots of site owners use our webmaster console to see how their site is doing in Google. Last week we began sending new messages to sites with a pattern of unnatural links pointing to them, and I wanted to give more context about these new messages.

Original Link Messages 

First, let’s talk about the original link messages that we’ve been sending out for months. When we see unnatural links pointing to a site, there are different ways we can respond. In many severe cases, we reduce our trust in the entire site. For example, that can happen when we believe a site has been engaging in a pretty widespread pattern of link spam over a long period of time. If your site is notified for these unnatural links, we recommend removing as many of the spammy or low-quality links as you possibly can and then submitting a reconsideration request for your site.

In a few situations, we have heard about directories or blog networks that won’t take links down. If a website tries to charge you to put links up and to take links down, feel free to let us know about that, either in your reconsideration request or by mentioning it on our webmaster forum or in a separate spam report. We have taken action on several such sites, because they often turn out to be doing link spamming themselves.

New Link Messages 

In less severe cases, we sometimes target specific spammy or artificial links created as part of a link scheme and distrust only those links, rather than taking action on a site’s overall ranking. The new messages make it clear that we are taking “targeted action on the unnatural links instead of your site as a whole.” The new messages also lack the yellow exclamation mark that other messages have, which tries to convey that we’re addressing a situation that is not as severe as the previous “we are losing trust in your entire site” messages.

How serious are these new link messages? 

These new messages are worth your attention. Fundamentally, it means we’re distrusting some links to your site. We often take this action when we see a site that is mostly good but might be might have some spammy or artificial links pointing to it (widgetbait, paid links, blog spam, guestbook spam, excessive article directory submissions, excessive link exchanges, other types of linkspam, etc.). So while the site’s overall rankings might not drop directly, likewise the site might not be able to rank for some phrases. I wouldn’t classify these messages as purely advisory or something to be ignored, or only for innocent sites.

On the other hand, I don’t want site owners to panic. We do use this message some of the time for innocent sites where people are pointing hacked anchor text to their site to try to make them rank for queries like [buy viagra].

Example scenario: widget links 

A fair number of site owners emailed me after receiving one of the new messages, and I think it might be helpful if I paraphrased some of their situations to give you an idea of what it might mean if you get one of these messages.

The first example is widget links. An otherwise white-hat site emailed me about the message. Here’s what I wrote back, with the identifying details removed:

“Looking into the very specific action that we took, I think we did the right thing. Take URL1 and URL2 for example. These pages are using your EXAMPLE1 widgets, but the pages include keyword-rich anchortext pointing to your site’s url. One widget has the link ANCHORTEXT1 and the other has ANCHORTEXT2. 

If you do a search for [widgetbait matt cutts] you’ll find tons of stories where I discourage people from putting keyword-rich anchortext into their widgets; see for example. So this message is a way to tell you that not only are those links in your widget not working, they’re probably keeping that page from ranking for the phrases that you’re using.” 

Example scenario: paid links 

The next example is paid links. I wrote this email to someone:

“I wouldn’t recommend that Company X ignore this message. For example, check out SPAMMY_BLOG_POST_URL. That’s a link from a very spammy website, and it calls into question the linkbuilding techniques that Company X has been using (we also saw a bunch of links due to widgets). These sorts of links are not helping Company X, and it would be worth their time to review how and why they started gathering links like this.” 

I also wrote to another link building SEO who got this message pointing out that the SEO was getting links from a directory that appeared to offer only paid links that pass PageRank, and so we weren’t trusting links like that.

Here’s a final example of paid links. I emailed about one company’s situation as follows:

“Company Y is getting this message because we see a long record of buying paid links that pass PageRank. In particular, we see a lot of low-quality ‘sponsored posts’ with keyword-rich anchortext where the links pass PageRank. The net effect is that we distrust a lot of links to this site. Here are a couple examples: URL1 and URL2. Bear in mind that we have more examples of these paid posts, but these two examples give a flavor of the sort of thing that should really be resolved. My recommendation would be to get these sort of paid posts taken down, and then Company Y could submit a reconsideration request. Otherwise, we’ll continue to distrust quite a few links to the site.” 

Example scenario: reputation management 

In some cases we’re ignoring links to a site where the site itself didn’t violate our guidelines. A good example of that is reputation management. We had two groups write in; one was a large news website, while the other was a not-for-profit publisher. Both had gotten the new link message. In one case, it appeared that a “reputation management” firm was using spammy links to try to push up positive articles on the news site, and we were ignoring those links to the news site. In the other case, someone was trying to manipulate the search results for a person’s name by buying links on a well-known paid text link ad network. Likewise, we were just ignoring those specific links, and the not-for-profit publisher didn’t need to take any action.

What should I do if I get the new link message? 

We recently launched the ability to download backlinks to your site sorted by date. If you get this new link message, you may want to check your most recent links to spot anything unusual going on. If you discover that someone in your company has been doing widgetbait, paid links, or serious linkspam, it’s worth cleaning that up and submitting a reconsideration request. We’re also looking at some ways to provide more concrete examples to make these messages more actionable and to help narrow down where to look when you get one.

Just to give you some context, less than 20,000 domains received these new messages—that’s less than one-tenth the number of messages we send in a typical month—and that’s only because we sent out messages retroactively to any site where we had distrusted some of the sites’ backlinks. Going forward, based on our current level of action, on average only about 10 sites a day will receive this message. 

Summing up 

I hope this post and some of the examples above will help to convey the nuances of this new message. If you get one of these new messages, it’s not a cause for panic, but neither should you completely ignore it. The message says that the current incident isn’t affecting our opinion of the entire website, but it is affecting our opinion of some links to the website, and the site might not rank as well for some phrases as a result.

This message reflects an issue of moderate severity, and we’re trying to find the right way to alert people that their site may have a potential issue (and it’s worth some investigation) without overly stressing out site owners either. But we wanted to take this extra step toward more transparency now so that we can let site owners know when they might want to take a closer look at their current links.

Posted by Matt Cutts, Distinguished Engineer

Behold Google index secrets, revealed!

julio 25
Webmaster level: All

Since Googlebot was born, webmasters around the world have been asking one question: Google, oh, Google, are my pages in the index? Now is the time to answer that question using the new Index Status feature in Webmaster Tools. Whether one or one million, Index Status will show you how many pages from your site have been included in Google’s index.

Index Status is under the Health menu. After clicking on it you’ll see a graph like the following:

It shows how many pages are currently indexed. The legend shows the latest count and the graph shows up to one year of data.

If you see a steadily increasing number of indexed pages, congratulations! This should be enough to confirm that new content on your site is being discovered, crawled and indexed by Google.

However, some of you may find issues that require looking a little bit deeper. That’s why we added an Advanced tab to the feature. You can access it by clicking on the button at the top, and it will look like this:

The advanced section will show not only totals of indexed pages, but also the cumulative number of pages crawled, the number of pages that we know about which are not crawled because they are blocked by robots.txt, and also the number of pages that were not selected for inclusion in our results.

Notice that the counts are always totals. So, for example, if on June 17th the count for indexed pages is 92, that means that there are a total of 92 pages indexed at this point in time, not that 92 pages were added to the index on that day only. In particular for sites with a long history, the count of pages crawled may be very big in comparison with the number of pages indexed.

All this data can be used to identify and debug a variety of indexing-related problems. For example, if some of your content doesn’t appear any more on Google and you notice that the graph of pages indexed has a sudden drop, that may be an indication that you introduced a site-wide error when using meta=”noindex” and now Google isn’t including your content in search results.

Another example: if you change the URL structure of your site and don’t follow our recommendations for moving your site, you may see a jump in the count of “Not selected”. Fixing the redirects or rel=”canonical” tags should help get better indexing coverage.

We hope that Index Status will bring more transparency into Google’s index selection process and help you identify and fix indexing problems with your sites. And if you have questions, don’t hesitate to ask in our Help Forum.

Posted by , and, Webmaster Tools Team

On web semantics

julio 17

Webmaster level: All

In web development context, semantics refers to semantic markup, which means markup used according to its meaning and purpose.

Markup used according to its purpose means using heading elements (for instance, h1 to h6) to mark up headings, paragraph elements (p) for paragraphs, lists (ul, ol, dl, also datalist or menu) for lists, tables for data tables, and so on.

Stating the obvious became necessary in the old days, when the Web consisted of only a few web sites and authors used tables to code entire sites, table cells or paragraphs for headings, and thought about other creative ways to achieve the layout they wanted. (Admittedly, these authors had fewer instruments at their disposal than authors have today. There were times when coding a three column layout was literally impossible without using tables or images.)

Up until today authors were not always certain about what HTML element to use for what functional unit in their HTML page, though, and “living” specs like HTML 5 require authors to keep an eye on what elements will be there going forward to mark up what otherwise calls for “meaningless” fallback elements like div or span.

To know what elements HTML offers, and what meaning these elements have, it’s necessary to consult the HTML specs. There are indices—covering all HTML specs and elements—that make it a bit simpler to look up and find out the meaning of an element. However, in many cases it may be necessary to check what the HTML spec says.

For example, take the code element:

The code element represents a fragment of computer code. This could be an XML element name, a filename, a computer program, or any other string that a computer would recognize.

Author-controlled semantics

HTML elements carry meaning as defined by the HTML specs, yet ID and class names can bear meaning too. ID and class names, just like microdata, are typically under author control, the only exception being microformats. (We will not cover microdata or microformats in this article.)

ID and class names give authors a lot of freedom to work with HTML elements. There are a few basic rules of thumb that, when followed, make sure this freedom doesn’t turn into problems:

Advantages of using semantic markup

Using markup according to how it’s meant to be used, as well as modest use of functional ID and class names, has several advantages:

  • It’s the professional thing to do.
  • It’s more accessible.
  • It’s more maintainable.

Special cases

“Neutral” elements, elements with ambiguous meaning, and presentational elements constitute special cases.

div and span offer a “generic mechanism for adding structure to documents.” They can be used whenever there is no other element available that matches what the contents in question represent.

In the past a lot of confusion was caused by the b, strong, i, and em elements. Authors cursed b and i for being presentational, and typically suggested a 1:1 replacement with strong and em. Not to stir up the past, here’s what HTML 5 says, granting all four elements a raison d’être:

b “a span of text to be stylistically offset from the normal prose without conveying any extra importance, such as key words in a document abstract, product names in a review, or other spans of text whose typical typographic presentation is boldened” <p>The <b>frobonitor</b> and <b>barbinator</b> components are fried.
strong “strong importance for its contents” <p><strong>Warning.</strong> This dungeon is dangerous.
i “a span of text in an alternate voice or mood, or otherwise offset from the normal prose, such as a taxonomic designation, a technical term, an idiomatic phrase from another language, a thought, a ship name, or some other prose whose typical typographic presentation is italicized” <p>The term <i>prose content</i> is defined above.
em “stress emphasis of its contents” <p><em>Cats</em> are cute animals.

Last but not least, there are truly presentational elements. These elements will be supported by user agents (browsers) for forever but shouldn’t be used anymore as presentational markup is not maintainable, and should be handled by style sheets instead. Some popular ones are:

  • center
  • font
  • s
  • u

How to tell whether you’re on track

A quick and dirty way to check the semantics of your page and understand how it might be interpreted by a screen reader is to disable CSS, for example using the Web Developer Toolbar extension available for Chrome and Firefox. This only identifies issues around the use of CSS to convey meaning, but can still be helpful.

There are also tools like W3C’s semantic data extractor that provide cues on the meaningfulness of your HTML code.

Other methods range from peer reviews (coding best practices) to user testing (accessibility).

Do’s and Don’ts

Don’t Do Reason
<p class"heading">foo</p>
For headings there are heading elements.
<p><font size="2">bar</font></p>

p { font-size: 1em; }
Presentational markup is expensive to maintain.
    <td class="heading">baz</td>
Use table elements for tabular data.
<div class="newrow">foo</div>
<div class="newrow">bar</div>
Use table elements for tabular data.
foo bar.<br><br>baz scribble.
<p>foo bar.</p>
<p>baz scribble.</p>
Denote paragraphs by paragraph elements, not line breaks.

Written by , Senior Web Architect, Google Webmaster Team

New Crawl Error alerts from Webmaster Tools

julio 13

Webmaster level: All

Today we’re rolling out Crawl Error alerts to help keep you informed of the state of your site.

Since Googlebot regularly visits your site, we know when your site exhibits connectivity issues or suddenly spikes in pages returning HTTP error response codes (e.g. 404 File Not Found, 403 Forbidden, 503 Service Unavailable, etc). If your site is timing out or is exhibiting systemic errors when accessed by Googlebot, other visitors to your site might be having the same problem!

When we see such errors, we may send alerts –- in the form of messages in the Webmaster Tools Message Center –- to let you know what we’ve detected. Hopefully, given this increased communication, you can fix potential issues that may otherwise impact your site’s visitors or your site’s presence in search.

As we discussed in our blog post announcing the new Webmaster Tools Crawl Errors feature, we divide crawl errors into two types: Site Errors and URL Errors.

Site Error alerts for major site-wide problems

Site Errors represent an inability to connect to your site, and represent systemic issues rather than problems with specific pages. Here are some issues that might cause Site Errors:

  • Your DNS server is down or misconfigured.
  • Your web server itself is firewalled off.
  • Your web server is refusing connections from Googlebot.
  • Your web server is overloaded, or down.
  • Your site’s robots.txt is inaccessible.

These errors are global to a site, and in theory should never occur for a well-operating site (and don’t occur for the large majority of the sites we crawl). If Googlebot detects any appreciable number of these Site Errors, regardless of the size of your site, we’ll try to notify you in the form of a message in the Message Center:

Example of a Site Error alert

The alert provides the number of errors Googlebot encountered crawling your site, the overall crawl error connection rate for your site, a link to the appropriate section of Webmaster Tools to examine the data more closely, and suggestions as to how to fix the problem.

If your site shows a 100% error rate in one of these categories, it likely means that your site is either down or misconfigured in some way. If your site has an error rate less than 100% in any of these categories, it could just indicate a transient condition, but it could also mean that your site is overloaded or improperly configured. You may want to investigate these issues further, or ask about them on our forum.

We may alert you even if the overall error rate is very low — in our experience a well configured site shouldn’t have any errors in these categories.

URL Error anomaly alerts for potentially less critical issues

Whereas any appreciable number of Site Errors could indicate that your site is misconfigured, overloaded, or simply out of service, URL Errors (pages that return a non-200 HTTP code, or incorrectly return an HTTP 200 code in the case of soft 404 errors) may occur on any well-configured site. Because different sites have different numbers of pages and different numbers of external links, a count of errors that indicates a serious problem for a small site might be entirely normal for a large site.

That’s why for URL Errors we only send alerts when we detect a large spike in the number of errors for any of the five categories of errors (Server error, Soft 404, Access denied, Not found or Not followed). For example, if your site routinely has 100 pages with 404 errors, we won’t alert you if that number fluctuates minimally. However we might notify you when that count reaches a much higher number, say 500 or 1,000. Keep in mind that seeing 404 errors is not always bad, and can be a natural part of a healthy website (see our previous blog post: Do 404s hurt my site?).

A large spike in error count could be because something has changed on your site — perhaps a reconfiguration has changed the permissions for a section of your site, or a new version of a script is crashing regularly, or someone accidentally moved or deleted an entire directory, or a reorganization of your site causes external links to no longer work. It could also just be a transient spike, or could be because of external causes (someone has linked to non-existent pages), so there might not even be a problem; but when we see an unusually large number of errors for your site, we’ll let you know so you can investigate:

Example of a URL Error anomaly alert

The alert describes the category of web errors for which we’ve detected a spike, gives a link to the appropriate section of Webmaster Tools so that you can see what pages we think are problematic, and offers troubleshooting suggestions.

Enable Message forwarding to send alerts to your inbox

We know you’re busy, and that routinely checking Webmaster Tools just to check for new alerts might be something you forget to do. Consider turning on Message forwarding. We’ll send any Webmaster Tools messages to the email address of your choice.

Let us know what you think, and if you have any comments or suggestions on our new alerts please visit our forum.

Written by Brian Malcolm, Webmaster Tools team