Unofficial StumbleUpon FAQ

new user restrictions

A user account is allowed to send messages only if the account (a) has a nickname specified, (b) has interests specified and (c) has existed for twenty-four hours.

A user account is allowed to post in forums (other than the Help forum) only if (a) the Stumble! button has been pressed for that account at least twenty-five times and (b) the account has existed for at least three days. If you believe that an account has satisfied those criteria but the account still isn't able to post, a likely cause is that a cookie needs to be reissued. The least complicated way to do that is to close all browser windows before trying again to post. (A savvy user can, alternately, selectively delete the PHPSESSID cookie.)

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password security

Your password is stored as plain text both in a cookie and elsewhere on your computer. It's also sent as plain text in communications with StumbleUpon servers. Choose a password unrelated to banking and e-commerce accounts.

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StumbleUpon tracks site ratings for the benefit of fellow stumblers. If you don't want to be identified with your ratings, blog entries, webpage comments or forum posts, choose a non-revealing nickname, and don't include personally identifiable information. To assist those wishing to remain anonymous, StumbleUpon guarantees not to share personally identifiable information except as required by court order, et cetera. See the formal privacy policy for details.

In addition to standard privacy guarantees, users who sponsor can hide the Recent thumb-up Sites (aka Favorites), hide blog entries (aka Recent Comments) or hide both by setting the number of items on the relevant list(s) to zero.

Although StumbleUpon offers more than enough anonymity for the casual user, that anonymity isn't complete. For instance if user Alice has a computer capable of serving HTTP, Alice can discover the host name of user Bob's computer. Realize that relaying the host name of your computer is part of the normal Web communication process and that most people don't consider sharing it to be a privacy intrusion. The procedure for discovering the host name of a user can be found in the document "Stumble Webbug Howto." Via an anonymizing proxy, a user can avoid divulging even that innocuous information.

Whether your "I like it!" ratings are indicated on the review page for a webpage depends on your Privacy Filter setting. For instance if your Privacy Filter is set to "No one can see your ratings", then you won't show up as Suggester on a page that you're the first to rate, and you won't show up in the list of avatars for persons who have recently rated a page "I like it!". The default Privacy Filter setting is "No one can see your adult ratings". (Note that many popular domain index pages show no Suggester because the default Privacy Filter setting for very old accounts was "No one can see your ratings".) The Privacy Filter setting is retroactive in that it affects visibility of all ratings (old and new) for all webpages outside the domain.

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premium features and sponsoring

Premium features are listed on the sponsoring info page. Here's a more verbose summary. A sponsor can...

  • be recognized by a green audience meter (as opposed to blue for a non-sponsor account).
  • get copies of sent and received Messages via e-mail.
  • stumble within the the Favorites of any Mutual Friend (as opposed to only the first 5 Mutual Friends for a non-sponsor account).
  • see a section labeled Shared Favorites (aka "Sharedthumb-up's") on the Blog page of some users' profiles.  note:  That section contains links to a few pages recently rated "I like it!" by both the owner of the profile and the sponsor who's viewing the profile. When Shared Favorites exist, the section appears between the About Me area and the Shared Topics area.
  • disable influence of sponsored stumbles.
  • create Groups.
  • upload a larger avatar image.
  • choose from 19 color themes (as opposed to 5 for a non-sponsor account).
  • use the "Buzz!" (aka Stumble Buzz) feature.  note:  Stumble Buzz is a page displaying comments attached to newly popular stumbles in your selected topics.
  • use the "followups" feature.  note:  Attached to each blog entry is a count of comments on the relevant review page that are dated later than your comment.
  • configure the number of Recent thumbup Sites in the range of 0-20 and configure the number of comments per Blog page in the range of 0-10.
  • see up to 20 stumblers in the Similar Stumblers section of the Stumblers profile page (as opposed to 10 for a non-sponsor account).
  • access the Sponsors forum.

Using Paypal is the preferred method for donating. If your payment through Paypal is via credit card, sponsorship takes effect immediately. If your payment through Paypal is via debit card or e-check, sponsorship takes effect as soon as Paypal notifies StumbleUpon that the payment has cleared (up to 5 days). See the sponsoring info page for details regarding these and other payment methods. That page also includes a convenient method for donating on behalf of another user.

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Stumble! button, Friends, Fans and rating

How both your Friends list and page ratings affect stumble selection is described by the following pages:

Here's a quick summary of behavior:

  • StumbleUpon correlates your "I like it!" and "Not-for-me" ratings with those of other users to select pages in your selected interests to serve via the Stumble! button.
  • When user Alice selects the Add as Friend button on user Bob's profile, Alice appears on Bob's Fans list.
  • Adding Friends enables another source for pages served via the Stumble! button. Quoting developer gmc: "Adding a friend is essentially subscribing to their content. You will stumble upon pages they have rated, filtered according to the shared [topics] displayed on that person's profile."
  • Having Mutual Friends enables another source for pages served via the Stumble! button: A Mutual Friend may send a stumble directly to your stumble queue via the Send Page to Mutual Friend toolbar button.
  • The Mutual Friends and Friends lists on the Friends page of your profile are ordered by most-to-least recently active, and the Fans list appears only for the owner of the profile.
  • A user with the mature filter turned on will not receive pages introduced to StumbleUpon by a user whose mature filter is turned off. Note that you may turn the mature filter off via the "Turn off mature filter" link on the interests page without necessarily selecting an adult topic for stumbling. That may be appropriate if you happen to be socially liberal and/or if you're eager to increase audience size.

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noteworthy official documentation

The official faq includes items addressing the following topics:

StumbleUpon has published some tips to help users get the most out of services.

The "Stumble! Button, Friends, Fans and Rating" item of this FAQ links to some documents that offer more detail regarding the goals and mechanics of stumbling and rating.

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audience meter and audience count

Sponsors receive a green audience meter, as opposed to the default blue audience meter.

The following help text for the audience feature describes the audience meter:

Audience is the number of people who 'stumble upon' sites rated by a particular stumbler. A stumbler's audience contains only people who have been recently active.

You can increase your audience by rating websites that other people will like, signing up for all topics you are interested in, and getting more people to make you their friend.

Audience size is measured on a scale of 0 to 5, 5 being the biggest.

Roughly speaking, the audience meter is a normalized representation of the audience count. Here's a relevant quote from developer gmc:

The audience rank is a percentile system, based on the number of people who give the same ratings as you. People with high ranks (level 5, or within the top 20 percent of all active users) are much like popular authors—everyone agrees with everything they rate, where those with low audience ranks are people with unpopular opinions or not very many ratings. This means your audience rank grows as you rate lots of useful pages, and reflects how helpful you are to the community.

The following phenomena can cause a user's audience to decrease:

  • Tweaks to the audience algorithm
  • User accounts being marked inactive and/or deleted
  • The user making unpopular ratings
  • The user making few recent ratings
  • Changes to topic category structure
  • Possibly changes to the user's topic selections
  • Changes to the user's adult filter state

See also the related official FAQ item.

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comments and blogging

Blogging (in case you're unfamiliar with the term) is short for "publishing a Web log." A Web log is an online journal of one sort or another.

While many users choose only to stumble and to rate, many others choose also to add commentary about webpages as they surf. The stumble toolbar makes it easy to build a blog featuring that commentary. You can add a comment to any webpage via the quote blogging feature, via the speech bubble (aka Page Reviews) toolbar button or via the image context menu item. A comment automatically appears both on the relevant review page and on your profile as a blog entry.

Experienced bloggers can also benefit from the convenience of the stumble toolbar: Via syndication, a blogger can incorporate StumbleUpon blog entries and/or rated pages into a blog or a news feed hosted elsewhere.

Here are some other details about blog entries and webpage comments:

  • Blog entries can be created and edited via the Post Comment form and the Edit! links on a user's profile page.
  • Blog entries feature automatically generated links and allow a subset of HTML markup.
  • Hiding blog entries doesn't delete the corresponding review page comments.
  • Users who enable the Prompt for Comment option have a third way to add a comment (in addition to the toolbar button and the context menu item cited above).

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images webservers will store only a user's avatar image. However, any image featured on most webpages can be included in a blog entry. StumbleUpon offers two methods for including an image, a context menu method and a manual method.

Details of the context menu method differ depending on which version of the toolbar you use. In the IE toolbar:

  1. Rate the page if it hasn't been rated before. (Most users choose to rate each blogged page rather than to visit the review page to determine whether the page has previously been introduced to StumbleUpon.)
  2. Right-click on an image to invoke a context menu.
  3. Select the "StumbleUpon: Blog This" context menu item, which will take you to the review page for the webpage containing the image.
  4. Note that some default markup is supplied in the comment form. You may add (either below or above the supplied markup) commentary about the page and/or the image.
  5. Select the Add Comment button.
  6. Select the URL link (at the top of the page) to return to the webpage.

In the Mozilla toolbar:

  1. Right-click (or Control-click on one-button Macintosh computers) on an image to invoke a context menu.
  2. Select the "StumbleUpon Photoblog It!" context menu item, which will rate the page "I like it!" and take you to the review page for the webpage containing the image.
  3. Note that some default markup is supplied in the comment form. You may add (either below or above the supplied markup) commentary about the page and/or the image.
  4. Select the Add Comment button.
  5. Select the URL link (at the top of the page) to return to the webpage.
  6. Optionally, re-rate the page "Not-for-me".

The second method for including an image in a blog entry or a webpage comment is to craft an HTML IMG element manually. For instance, this markup

<a href="" border=0><img src=""></a>
will include this linked image
stumble toolbar .
And this markup
<img src="">
will include this non-linked image
stumble toolbar .

See the "markup" item of this FAQ for more details regarding markup and rendering.

Beware that some websites disallow external linking to images (aka hotlinking). For instance, some publishers prefer that content not be featured (and consume serving bandwidth) outside the context of the published page. Unless the page containing the image specifically mentions a prohibition on external linking, the best advice is to try and see. If external linking is disallowed, the served image may be moved, or an image with a notice about external linking may be substituted.

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miscellaneous toolbar features

quote blogging
Note that rating a page causes a green arrow to appear on the speech bubble (aka Page Reviews) toolbar button. If text is selected on the rated webpage page prior to clicking the Page Reviews button, a copy of the selected text is supplied as default text in the comment dialog on the review page. That copied text appears in quotes, prefixed by "From the page: ".
Stumble After Rating
To automatically advance to the next stumble upon rating a page, enable Stumble After Rating on the toolbar preferences dialog (accessible via the Toolbar Options menu item). Most users choose to enable Stumble After Rating Not-for-me. Note that the Stumble After Rating feature occasionally causes confusion: A user experimenting with toolbar preferences will sometimes enable Stumble After Rating "I like it!" then become confused when rating a site causes a new page to be served.
Show Page Review in New Window
This feature exists only for the Mozilla toolbar. To cause the speech bubble (aka Page Reviews) toolbar button to open a new window/tab, enable "Show Page Review in New Window" on the toolbar preferences dialog (accessible via the Toolbar Options menu item). Whether a new window or a new tab opens depends on browser configuration.
Prompt for Comment
To be prompted for a comment when you introduce a new page to StumbleUpon, enable the relevant item in the Other section of the toolbar preferences dialog (accessible via the Toolbar Options menu item).
stumble or navigate to a new window/tab
This feature exists only for the Mozilla toolbar. Right-clicking or middle-clicking on most toolbar buttons, including the Stumble!, button causes the resulting page to open in a new window or tab.

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By joining a group you advertise your interest in a topic. A given group may have any sort of theme. Examples of themes include casual conversation, culinary exploration, an obscure interest, a social movement, an academic discipline, et cetera. Some groups focus more on collecting webpage recommendations via the Sites list, and others focus more on conversations via forum threads. Here are some details regarding groups:

  • You can view recent posts in all forum threads by appending "?all" to the URL for the Forum page of your profile. Alternately, you can use the following URL:
  • You can search a forum via the Search field at the bottom of the forum index page. Access a forum index page via the "Add/View Posts" link on the group index page. For example, the Search field appears on the forum index page for the Features group.
  • When you add a URL to the Sites list, StumbleUpon automatically rates that page "I like it!".
  • A given account is not allowed to add two consecutive items to the Sites list for a group. If you have more than one page to recommend, you have the following options:
    • request that another active group member (such as the group owner) add the URL
    • wait for another group member to add a URL
    • paste the URLs into a forum post  (note:  This will not add the items to the Sites list and will not automatically rate the pages.)
    • use a second account to add the URL.
  • Any sponsor can create a group.
  • A group owner can delete any item from the Sites list and can delete any forum thread.
  • If user Alice ignores user Bob, then Bob's posts don't appear in Alice's view of a thread in which Bob has participated.

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ignoring a user

The ignore feature allows one user to avoid associating with another user. To ignore a user, select the Ignore Me button on the user's profile. To unignore a user, use the Edit Ignore section at the bottom of the Stumblers page of your profile. Here are some details regarding behavior when user Alice ignores user Bob:

  • Bob cannot message Alice, because the Send Message form doesn't appear on Bob's view of Alice's profile.
  • Comments made by Bob on the review page for Alice's profile disappear for all users. (The comment remains visible to all users in Bob's blog.)
  • Forum posts made by Bob don't appear in Alice's view of a thread.
  • Bob's avatar doesn't appear in Alice's Fans list or Recent Visitors list.

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You can control presentation using a subset of HTML. Here are some details regarding markup and rendering:

  • A link is automatically generated from a URL in a forum post or a blog entry. But a link is not automatically generated from a URL in a message, in a webpage comment or in About Me text.
  • Although it isn't a supported feature, you can add a local-time clock and/or local weather to your About Me area.
  • The following HTML elements can be used: <a>, <img>, <ul>, <ol>, <li>, <br>, <font>, <pre>, <b>, <em>, <i> and <del>. (See the "images" item of this FAQ for examples featuring the <a> and <img> elements.)
  • The style attribute of the aforementioned HTML elements cannot be used.
  • Any Unicode character can be included via the "&[entity-name];" syntax, via the "&#[char-code];" syntax or as a literal. However, upon editing, the text presented to be edited will contain the character as rendered rather than the originally supplied markup. Most of the time that isn't a problem, but it can be problematic for &nbsp; and &lt;.
  • Line breaks behave as expected in blog entries and forum posts (i.e. linefeeds are translated to <br> tags automatically), but <br> tags must be entered explicitly to create line breaks in webpage comments, messages or About Me text.
  • Leading and trailing whitespace is always omitted.
  • BBCode is not supported.
  • Javascript event attributes (such as onclick) of the aforementioned HTML elements cannot be used.

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The orange RSS and RSS Comments icons at the bottom of the Blog page of each profile link to pages containing a machine-readable version of your recent blog entries and your Recent thumb-up Sites. This facility can be used to monitor a set of blogs or to incorporate your StumbleUpon blog content into an external blog. A sponsor can disable this facility.

To monitor a set of blogs, use a RSS news feed reader. A StumbleUpon RSS feed displays particularly well with the RSS Reader Panel extension for Mozilla Firefox, but virtually any news feed reader will work.

The procedure for incorporating your StumbleUpon blog content into an external blog depends on what software implements the external blog. For example, user Nog has published some notes that describe using the Magpie RSS parser to provide content for a PHP-based blog.

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To assist stumble filtering, you should indicate language proficiency via the Languages Spoken field on the Edit page of your profile.

In addition to stumble filtering, specifying a less common language may also help a user to find ethnically similar users via the language description page. A language description page can be accessed via a URL of the following form:[language_name]/
such as

To request that a language be added to the list of available languages, submit a request via the feedback form.

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favorite list item conventions

StumbleUpon uses standard title capitalization conventions for items in the Music, Movie, Books, TV and "What I like" lists. In addition, the database uses a normalizing comparison when determining whether a user-specified item is new. The normalizing comparison ignores capitalization, punctuation and initial articles (such as "The"). If user Bob is the first to list the album "dark side of the moon" and user Alice subsequently lists the album "The Dark Side of the Moon", then the text "Dark Side of the Moon" (regardless whether that's most correct) will appear in Alice's favorite music list.

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topic categories and miscategorized URLs

Within fifteen minutes, a newly rated URL will be associated automatically with a stumble topic category. The subsystem for automatically categorizing has mixed success, and improvements are being developed. Manual categorizing augments automatic categorizing. Two types of manual categorizing exist. The person who first introduces a page to StumbleUpon has the option to preempt automated categorizing by selecting a topic on the review page for the stumble. The second sort of manual categorizing is available to anyone but is a two-tiered process. First, a user suggests an alternate topic by submitting a miscategorization report (aka miscat). Then, a set of system administrators and volunteers review miscats. Miscats are sent to those reviewers in order of decreasing popularity. A miscat for a popular page will generally be reviewed within twenty-four hours. The lead time for reviewing a miscat for a less popular page depends on the volume of miscats.

To submit a miscat:

  1. Go to the review page by using the speech bubble (aka Page Reviews) toolbar button.
  2. Select the "[Update]" link adjacent to the current topic name (in the Website row near the top of the page).
  3. Choose a more appropriate topic. If no topic seems appropriate or if you don't want to spend time becoming acquainted with the set of topics, select the "I don't know" option.
  4. If you submit miscats frequently, consider including your name or nickname in the optional "Description of Problem" field.

Note that when a user selects a topic for stumbling, the Stumble! button will return pages in that topic category as well as highly rated pages in Related topics. Related topics are listed in the Related section of a topic page. (See the Animals topic page for an example.)

To submit a request for a new category:

  • Use the feedback form.
  • Please justify your request, possibly by listing some pages that belong in the new category and don't belong in any existing category.

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reappearing junk pages, redirects, session IDs and 404s

When a user rates a page, StumbleUpon associates the rating with the URL for the page. A few phenomena can cause ratings to be misdirected, namely (A) content on a page can change, (B) a popular URL can be redirected, (C) a page can be removed or (D) a page can be served via a URL that is user- or session-specific.

Cases B and C can be the most problematic for users of the Stumble! button. A traditional standards-compliant website will return a 404 error when a page is removed. These well-behaved 404s are detected automatically in time. But often a website—particularly one managed by a hosting company—will redirect the old URL to an index page or a search page. Redirecting also occurs frequently when a domain name is purchased by another company. Rating "Not-for-me" on the ultimate target of the redirection doesn't affect the old URL, which allows the old URL to retain its high rating. Instead, select Menu->Report->Report 404 from the toolbar menu (which is available only for the Mozilla toolbar as of this writing). That reports both the ultimate target and the most recently served URL.

Case D occurs primarily on commercial websites. In one common implementation, a user is redirected from the requested URL to a URL including a user ID or a session ID. Ontologically, this is often appropriate if the page being served is customized to the user or the session. For instance, Amazon serves different content to each user to customize the shopping experience. However, often a page contains little or no customized content and still is identified via a user- or session-specific URL. Unfortunately since each user sees a different URL, StumbleUpon can't track ratings for the static content.

Developers have solicited suggestions and, preferably, code contributions for tackling cases B, C and D.

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raising bug or feature issues

Many services of StumbleUpon are still under active development. And the StumbleUpon developers appreciate feedback. Even a seemingly trivial bug deserves to be reported. Beginning a new thread in the Features forum or the Bugs forum is the primary means to raise an issue. Before starting a new thread, please try to avoid duplicating an issue report by scanning recent threads in those two forums and/or by searching those forums. Use one of the following checklists to help create a useful issue report:

For a bug, use this checklist:

  • Use a descriptive subject!
  • Include relevant platform information. For instance, if the bug is related to a toolbar feature, include the toolbar version, the browser version and the OS version. If the bug is related to a profile feature or a group feature, include the browser version and the OS version.
  • If possible, test with multiple platforms to determine whether the bug is platform-specific.
  • Describe actions required to reproduce the bug.
  • If the bug report relates to an error message, include the text of the error message. Those users with access to an image server may choose to serve a screenshot and to include a URL to the screenshot with the bug report.

For a feature request, use this checklist:

  • Use a descriptive subject!
  • Describe not only your proposed feature but also the problem or need being addressed. Realize that identifying a problem or a need is often more helpful than outlining an immature proposal; developers may be able to devise a solution that's more compatible with site ontology and infrastructure.
  • If you happen to be a programmer, realize that portions of StumbleUpon are open source and that the developers gladly accept code contributions. Here's a relevant quote from developer Geoff Smith:

    I would *love* to have more people submitting patches to stumbleupon. The mozilla toolbar source code is under MPL, the cvs is publicly available. I have already given 1 stumbler write access to CVS.

    I have had a lot of people ask how they can see the code/contribute to the code. However only 2 people have ever submitted patches. I really appreciated their contributions, please send more!

In addition to the Bugs and Features forums, StumbleUpon offers a formal issue tracking system called StumbleUpon Bugzilla. Historically, it has been unevenly employed by StumbleUpon developers, but it's a good venue for the following:

  • reporting minor bugs or typos
  • tracking an issue of particular interest
  • summarizing the deliberations and/or consensus derived from forum posts that discuss a bug or a feature request.

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blog entry
an item in the comments section of the Blog page of a stumbler's profile
favorite (aka thumb-up Site, aka thumb-up Page)
a stumble that has been rated "I like it!" by a given user
IE toolbar
the StumbleUpon toolbar for the Internet Explorer browser and for other browsers such as Maxthon (formerly named MyIE2) that use Internet Explorer services
a miscategorization report
note:  See the "topic categories and miscategorized URLs" item of this FAQ for details.
Mozilla toolbar (aka mozbar)
the StumbleUpon toolbar (or, more precisely, a browser extension) for browsers based on work of the Mozilla project
note:  The Mozilla toolbar usually sees feature additions before the IE toolbar.
note:  Stumblers frequently recommend the Mozilla Firefox browser, augmented by the Tabbrowser Extensions extension, in preference to Internet Explorer.
a stumbler's username, configurable via the Edit page of that user's profile
the set of pages where a stumbler's personal information (if supplied) and statistics are published
1. a webpage known to the StumbleUpon database via its URL and, hence, servable via the Stumble! button of a StumbleUpon toolbar
2. a nickname for the services of StumbleUpon
review page
a page accessible via the speech bubble (aka Page Reviews) toolbar button
note:  An example is the review page for this FAQ.
a user of StumbleUpon services
webpage comment
an item on the review page for a webpage

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Major FAQ items contributed by Joe Walp.
FAQ maintained by Joe Walp and ThePrawn.

The unofficial FAQ is in no way associated with StumbleUpon, which is ©
Visit the official StumbleUpon FAQ
Version 2.1, Revision 2004-10-08-a

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