A tutorial for searching with blekko

Welcome! This tutorial is intended to teach you some of the unique features of the blekko search engine. It starts with search basics, explains blekko’s special slashtag feature, and finishes up by discussing privacy and safe searching.

For more general help, please see our help pages.

Search basics

Asking blekko to search for several words means that we will interpret these two words liberally. We’ll include results with both singular and plural forms of words, for example we will match “word” as well as “words”. We might return results containing “multiple” instead of “several,” because these words are similar. And we will include results where “several” and “words” aren’t next to one another. This is the way all search engines do normal searches.

Results for [several words]

If you add quotes around individual words: “several” “words”, we will return results containing only these exact words, without synonyms or plurals. If you add quotes around a phrase: “several words”, we will require the words to be next to each other, in that order, in the results.

Results for "several words"

You can ask for results that do not include a particular word by adding a minus sign before it: pie recipes -apple. This is useful if you’ve done a search and it returned many unwanted results containing the same word, in this example “apple”. You can negate several words: apple recipes -pie -crisp.


Slashtags are blekko’s way of giving you access to the full power of our search engine, without making you wade through lots of graphical UI or menus. In fact, the main feature of slashtags is that they let blekko ship features that our graphics designers could never think up a pretty interface for. Think of them as the command line of search engines.

Slashtags are expressed by typing additional words into the search box. As an example, searching for blekko /blogs will return only results that are blogs, and blekko /blogs /date will sort that result by date. The most interesting uses of slashtags can produce results that are impossible to generate in other search engines.

Slashtags are divided into 4 main types.

/ps=N is an example of a utility slashtag; it modifies the number of results blekko will display.

Topical slashtags are built by human editors, and power blekko’s human curation and anti-spam features. For example, the /health slashtag contains around 200 websites with high-quality health information.

cure for headaches /health

To see the full list of websites in /health, type /view /health into the search box.

The websites in /health are selected by blekko’s in-house librarian team, working with volunteer medical professional editors. Our policy for this slashtag is that it is limited to websites with conventional medicine content where 100% of the content is doctor-reviewed. If you’re interested in non-conventional medicine, we also have

And that’s just the alternatives beginning with the letter “a”! This focus on source authority and categorized search is basically impossible to replicate with an algorithm, or by typing words into the search box.

Topical slashtags can also be combined with /date, to change the sort order. For example:

debate /libertarian /date

A complete list of high-quality blekko-built topical slashtags can be found by clicking on the “slashtag directory” link on any results page. A few important ones include: /topnews, /sports, /politics, /gossip, /arts, /business, /culture, and /fashion. If you’re wondering why we chose some of these categories (like /fashion and /home), the reason is that in order to reduce spam for searchers who don’t explicitly use slashtags, we needed to create slashtags for every category on the Internet that has a lot of advertising money behind it. Advertising money causes webspam to spring into existence, and our anti-spam goal requires us to be able to clean up searches in all of the major spammed-up categories.

As an example of how these slashtags can be useful, look at the difference between the search results for:

Another example of using topical slashtags to slice-and-dice the web into different viewpoints are searches about the controversial topic of climate change. Compare:

Topical slashtags can be included within each other. In addition to the 200 general health websites in the /health slashtag, /health also includes a bunch of specialist slashtags named /cardiology, /diabetes, and so on. These specialist slashtags can be used directly, and are also included in /health. (You can view the list of included slashtags in /health by looking at the top of /view /health.)

Algorithmic slashtags are generated by algorithms built into blekko’s crawler. For example, websites and parts of websites that are blogs are identified in our crawler. Additional examples of algorithmic slashtags include /forums and /people. /people is used to search pages that are resumes, biographies, and personal homepages. /forums limits your search to forum websites.

Shortcut slashtags are used to access 3rd party services. Examples include:

These searches are farmed out to bing image search, bing maps, YouTube, Yahoo Finance, Weather Underground, Wolfram Alpha, and so forth.

If you use multiple slashtags together in a single search, the results will have to be in all of the slashtags. For example obama /topnews /conservative will only include results from websites which are included in both the /topnews and /conservative slashtags. Some combinations, however, do not work: 3rd party services slashtags such as /images and /videos cannot be combined with topical slashtags like /politics.

You can create your own topical slashtags. This is discussed in the 2nd half of this tutorial.

Boosted and auto-boosted slashtags

Topical slashtags can be used in 2 different ways: exclusively within a slashtag headache /health or as a boost headache +/health. In the exclusive form, all results will be from the curated sites in the /health slashtag. In the boosted form, the entire web will be searched, but any results in the /health slashtag will have their rank boosted. Boosting allows highly-ranked results that are not in the slashtag to still be included in the final results. A search with exclusive /health will never contain spam if /health is kept spam-free; the boosted +/health is unlikely to contain spam, but it’s always possible that queries like autism cure +/health will contain a highly ranked result from outside of /health which may be considered spam or off-topic by a human curator.

A mainly non-health keyword combined with boosted +/health (such as obama +/health) will frequently include results from outside the /health slashtag. (Compare to obama /health.)

In order to fight spam for users uninterested in explicitly using slashtags, we attempt to guess the topic of every slashtag-less search, and boost a slashtag for it. This is called auto-boosting, and it currently happens about 1/3 of the time for non-navigational searches. For example, searching for cure for headaches will auto-boost +/health. If you find the auto-boosted slashtag to be unhelpful, you can turn off auto-boost by adding /web to your search: cure for headaches /web.

Negating slashtags

Topical and algorithmic slashtags can be negated by using the minus sign: blekko -/blog will return non-blog webpages mentioning blekko, while blekko -/tech will return results from websites which are not in the /tech slashtag. Negating slashtags work better with broad slashtags (such as /blog) than with narrow ones (like /gossip).

Every logged-in user has a personal /spam slashtag which is negated in every search that they do. Adding a website to this slashtag means it will disappear from your personal results.

Other examples of interesting uses of negating slashtags include searching less-popular news websites, e.g. romney /news -/topnews, or looking at popular but not liberal news websites: romney -/liberal /topnews.

We’ve even created slashtags intended to always be used in a negative fashion — there are a series of slashtags containing the most popular 10, 100, 1,000, 10,000, and 100,000 websites on the Internet. It can be very interesting to exclude these websites from searches, in order to deliberately avoid popular websites. These slashtags have names like /top10/top10, /top10/top1000, /top10/top10k, and /top10/top100k. (Why are these slashtag names more complicated than usual? It’s because they are owned by the user named “top10″. This is fully explained in the 2nd half of this tutorial.) An example search using these slashtags is searching for news about Obama that’s not in the most popular 100,000 websites: obama /news -/top10/top100k.

A few search tips

If you’ve arrived at a result webpage and can’t see one of your search terms, try using control-f (PC, Linux) or command-f (Mac) to search within the webpage. If you still can’t find the search term, remember that it might be present only in the anchortext of an incoming link.

Search engines usually ignore capitalization and punctuation. There are a few terms, like C++ and C#, for which punctuation can be searched for, but in most cases punctuation is completely ignored. For example, if you’re searching for a phone number, (650) 555-1212 is the same as 650 555 1212. Punctuation in quoted phrases is also ignored, but the order of the words is preserved. “650 555 1212″ will successfully match variations of the phone number written with parentheses and dashes.

The order of words in your query is somewhat ignored. If you wish to enforce word order, use quotes: compare rare phrase to “rare phrase”. Since blekko indexes pairs and triples of adjacent words, you should put words together that belong together. If you’re interested in webpages mentioning John Smith and Fred Brown, searching for John Smith Fred Brown will return much better results than searching for John Fred Smith Brown.

Search engines mainly work on words, not sentences. Compare:

Safe Searching

blekko’s safe-search features are similar to the safe-search offered by other search engines. By default, safe search is set to “moderate”, which means that porny results will be visible only if a majority of results are porn. If you wish to always see all results, click on “prefs” in the upper right and set safe-search to “disabled”. Alternately, you can set safe-search to “strict”, and porny results will never be shown. Keep in mind that our porn classifier is not 100% accurate, and naughty search terms can return occasional porny results even when safe-search is set to strict. Also, remember that if autoboosted slashtags are getting in the way of the results you want, add /web to disable autoboosting.

The blekko user preferences menu


blekko is committed to search privacy, and uses “privacy by design” to retain minimal information. We discard almost all personal information, such as your IP address, after 48 hours. Please see our privacy policy for full details.

To increase your privacy, we recommend that you click on the “prefs” menu in the upper right, and select “Always use HTTPS on blekko”, which keeps your searches more private against the bad guy listening to the insecure WiFi in the coffee shop, and your Internet Service Provider (ISP). Many ISPs collect data on your browsing habits, and sell this data to marketing companies.

Our “HTTPS Preferred” feature defaults on, and means that we will send you to the HTTPS (encrypted) version of a result page, if we know that one exists.

We already do not track you in the way the DoNotTrack initiative recommends, but if you have DoNotTrack enabled in your browser, or select “Less Logging”, we will not include your searches in our fully anonymized search summaries, even in the data that we use to study and improve results of our search engine.

You can turn off ads if you like; we can’t guarantee that our ad providers are respecting your privacy. Finally, selecting “Super Privacy” will keep you as private as possible, although you should note that the “No External DYM” option will degrade your search results, sometimes significantly.


Aside from the use of private slashtags and the /spam slashtag, blekko currently does no personalization of results. If we do so in the future, we will provide a way to know personalization is happening, and to disable the feature. We do sometimes localize results; if so, it will be obvious, and adding /web will disable localization.

Making blekko the default or optional search engine in your web browser

You can make blekko your default search engine in most browsers, including Firefox, Chrome, Safari, and Internet Explorer.

For more information

Please see Advanced Search Features for further information about searching with blekko. If you have questions or wish to offer feedback about how good or bad our results are, please use the “file bugs/feedback” link on any search result, or send email to support@blekko.com. Thank you for your interest in blekko, and thank you for reading this tutorial!

About greg

I'm the CTO at blekko
This entry was posted in customization, getting started, search, slashtags and tagged . Bookmark the permalink.

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