Frequently asked questions
==========================
:title: Frequently asked questions
The Compiler <mail@qutebrowser.org>

[qanda]
What is qutebrowser based on?::
    qutebrowser uses http://www.python.org/[Python], http://qt.io/[Qt] and
    http://www.riverbankcomputing.com/software/pyqt/intro[PyQt].
+
The concept of it is largely inspired by http://portix.bitbucket.org/dwb/[dwb]
and http://www.vimperator.org/vimperator[Vimperator]. Many actions and
key bindings are similar to dwb.

Why another browser?::
    It might be hard to believe, but I didn't find any browser which I was
    happy with, so I started to write my own. Also, I needed a project to get
    into writing GUI applications with Python and
    link:http://qt.io/[Qt]/link:http://www.riverbankcomputing.com/software/pyqt/intro[PyQt].
+
Read the next few questions to find out why I was unhappy with existing
software.

What's wrong with link:http://portix.bitbucket.org/dwb/[dwb]/link:http://sourceforge.net/projects/vimprobable/[vimprobable]/link:https://mason-larobina.github.io/luakit/[luakit]/link:http://pwmt.org/projects/jumanji/[jumanji]/... (projects based on WebKitGTK)?::
    Most of them are based on the http://webkitgtk.org/[WebKitGTK+]
    http://webkitgtk.org/reference/webkitgtk/stable/index.html[WebKit1] API,
    which causes a lot of crashes. As the GTK API using WebKit1 is
    https://lists.webkit.org/pipermail/webkit-gtk/2014-March/001821.html[deprecated],
    these bugs are never going to be fixed.
+
The newer http://webkitgtk.org/reference/webkit2gtk/stable/index.html[WebKit2
API] seems to lack basic features like proxy support, and almost no projects
seem to have started porting to WebKit2 (I only know of
http://www.uzbl.org/[uzbl]).
+
qutebrowser uses http://qt.io/[Qt] and http://wiki.qt.io/QtWebKit[QtWebKit]
instead, which suffers from far less such crashes. It might switch to
http://wiki.qt.io/QtWebEngine[QtWebEngine] in the future, which is based on
Google's https://en.wikipedia.org/wiki/Blink_(layout_engine)[Blink] rendering
engine.

What's wrong with https://www.mozilla.org/en-US/firefox/new/[Firefox] and link:http://5digits.org/pentadactyl/[Pentadactyl]/link:http://www.vimperator.org/vimperator[Vimperator]?::
    Firefox likes to break compatibility with addons on each upgrade, gets
    slower and more bloated with every upgrade, and has some
    https://blog.mozilla.org/advancingcontent/2014/02/11/publisher-transformation-with-users-at-the-center/[horrible
    ideas] lately.
+
Also, developing addons for it is a nightmare.

What's wrong with http://www.chromium.org/Home[Chromium] and https://vimium.github.io/[Vimium]?::
    The Chrome plugin API doesn't seem to allow much freedom for plugin
    writers, which results in Vimium not really having all the features you'd
    expect from a proper minimal, vim-like browser.

Why Python?::
    I enjoy writing Python since 2011, which made it one of the possible
    choices. I wanted to use http://qt.io/[Qt] because of
    http://wiki.qt.io/QtWebKit[QtWebKit] so I didn't have
    http://wiki.qt.io/Category:LanguageBindings[many other choices]. I don't
    like C++ and can't write it very well, so that wasn't an alternative.

But isn't Python too slow for a browser?::
    http://www.infoworld.com/d/application-development/van-rossum-python-not-too-slow-188715[No.]
    I believe efficiency while coding is a lot more important than efficiency
    while running. Also, most of the heavy lifting of qutebrowser is done by Qt
    and WebKit in C++, with the
    https://wiki.python.org/moin/GlobalInterpreterLock[GIL] released.

Is there an adblocker?::
    There is a host-based adblocker which takes /etc/hosts-like lists. A "real"
    adblocker has a
    http://www.reddit.com/r/programming/comments/25j41u/adblock_pluss_effect_on_firefoxs_memory_usage/chhpomw[big
    impact] on browsing speed and
    https://blog.mozilla.org/nnethercote/2014/05/14/adblock-pluss-effect-on-firefoxs-memory-usage/[RAM
    usage], so implementing support for AdBlockPlus-like lists is currently not
    a priority.

How do I play Youtube videos with mpv?::
    You can easily add a key binding to play youtube videos inside a real video
    player - optionally even with hinting for links:
+
----
:bind m spawn mpv {url}
:bind M hint links spawn mpv {hint-url}
----
+
Note that you might need an additional package (e.g.
https://www.archlinux.org/packages/community/any/youtube-dl/[youtube-dl] on
Archlinux) to play web videos with mpv.
+
There is a very useful script for mpv, which emulates "unique application"
functionality. This way you can add links to the mpv playlist instead of
playing them all at once.
+
You can find the script here: https://github.com/mpv-player/mpv/blob/master/TOOLS/umpv
+
It also works nicely with rapid hints:
+
----
:bind m spawn umpv {url}
:bind M hint links spawn umpv {hint-url}
:bind ;M hint --rapid links spawn umpv {hint-url}
----

How do I use qutebrowser with mutt?::
    Due to a Qt limitation, local files without `.html` extensions are
    "downloaded" instead of displayed, see
    https://github.com/qutebrowser/qutebrowser/issues/566[#566]. You can work
    around this by using this in your `mailcap`:
+
----
    text/html; mv %s %s.html && qutebrowser %s.html >/dev/null 2>/dev/null; needsterminal;
----

What is the difference between bookmarks and quickmarks?::
    Bookmarks will always use the title of the website as their name, but with quickmarks
    you can set your own title.
+
For example, if you bookmark multiple food recipe websites and use `:open`, 
you have to type the title or address of the website.
+
When using quickmark, you can give them all names, like
`foodrecipes1`, `foodrecipes2` and so on. When you type 
`:open foodrecipes`, you will see a list of all the food recipe sites,
without having to remember the exact website title or address.

How do I use spell checking?::
    Qutebrowser's support for spell checking is somewhat limited at the moment
    (see https://github.com/qutebrowser/qutebrowser/issues/700[#700]), but it
    can be done.
+
For QtWebKit:

. Install https://github.com/QupZilla/qtwebkit-plugins[qtwebkit-plugins].
  . Note: with QtWebKit reloaded you may experience some issues. See
    https://github.com/QupZilla/qtwebkit-plugins/issues/10[#10].
. The dictionary to use is taken from the `DICTIONARY` environment variable.
  The default is `en_US`. For example to use Dutch spell check set `DICTIONARY`
  to `nl_NL`; you can't use multiple dictionaries or change them at runtime at
  the moment.
  (also see the README file for `qtwebkit-plugins`).
. Remember to install the hunspell dictionaries if you don't have them already
  (most distros should have packages for this).

+
For QtWebEngine:

. Not yet supported unfortunately :-( +
  Adding it shouldn't be too hard though, since QtWebEngine 5.8 added an API for
  this (see
  https://github.com/qutebrowser/qutebrowser/issues/700#issuecomment-290780706[this
  comment for a basic example]), so what are you waiting for and why aren't you
  hacking qutebrowser yet?

How do I use Tor with qutebrowser?::
    Start tor on your machine, and do `:set network proxy socks://localhost:9050/`
    in qutebrowser. Note this won't give you the same amount of fingerprinting
    protection that the Tor Browser does, but it's useful to be able to access
    `.onion` sites.

Why does J move to the next (right) tab, and K to the previous (left) one?::
    One reason is because https://bitbucket.org/portix/dwb[dwb] did it that way,
    and qutebrowser's keybindings are designed to be compatible with dwb's.
    The rationale behind it is that J is "down" in vim, and K is "up", which
    corresponds nicely to "next"/"previous". It also makes much more sense with
    vertical tabs (e.g. `:set tabs position left`).

What's the difference between insert and passthrough mode?::
    They are quite similar, but insert mode has some bindings (like `Ctrl-e` to
    open an editor) while passthrough mode only has escape bound. It might also
    be useful to rebind escape to something else in passthrough mode only, to be
    able to send an escape keypress to the website.

Why takes it longer to open an URL in qutebrowser than in chromium?::
    When opening an URL in an existing instance the normal qutebrowser
    Python script is started and a few PyQt libraries need to be
    loaded until it is detected that there is an instance running
    where the URL is then passed to. This takes some time.
    One workaround is to use this
    https://github.com/qutebrowser/qutebrowser/blob/master/scripts/open_url_in_instance.sh[script]
    and place it in your $PATH with the name "qutebrowser". This
    script passes the URL via an unix socket to qutebrowser (if its
    running already) using socat which is much faster and starts a new
    qutebrowser if it is not running already. Also check if you want
    to use webengine as backend in line 17 and change it to your
    needs.
    
== Troubleshooting

Configuration not saved after modifying config.::
    When editing your config file manually, qutebrowser must be exited completely.
    This can be done by issuing the command `:quit` or by pressing `Ctrl+q`.

Unable to view flash content.::
    If you have flash installed for on your system, it's necessary to enable plugins
    to use the flash plugin. Using the command `:set content.plugins true`
    in qutebrowser will enable plugins. Packages for flash should
    be provided for your platform or it can be obtained from
    http://get.adobe.com/flashplayer/[Adobe].

Experiencing freezing on sites like duckduckgo and youtube.::
    This issue could be caused by stale plugin files installed by `mozplugger`
    if mozplugger was subsequently removed.
    Try exiting qutebrowser and removing `~/.mozilla/plugins/mozplugger*.so`.
    See https://github.com/qutebrowser/qutebrowser/issues/357[Issue #357]
    for more details.

Experiencing segfaults (crashes) on Debian systems.::
    For Debian it's highly recommended to install the `gstreamer0.10-plugins-base` package.
    This is a workaround for a bug in Qt, it has been fixed upstream in Qt 5.4
    More details can be found
    https://bugs.webkit.org/show_bug.cgi?id=119951[here].

Segfaults on Facebook, Medium, Amazon, ...::
    If you are on a Debian or Ubuntu based system, you might experience some crashes
    visiting these sites. This is caused by various bugs in Qt which have been
    fixed in Qt 5.4. However Debian and Ubuntu are slow to adopt or upgrade
    some packages. On Debian Jessie, it's recommended to use the experimental
    repos as described in https://github.com/qutebrowser/qutebrowser/blob/master/doc/install.asciidoc#on-debian--ubuntu[the documentation].
+
Since Ubuntu Trusty (using Qt 5.2.1),
https://bugreports.qt.io/browse/QTBUG-42417?jql=component%20%3D%20WebKit%20and%20resolution%20%3D%20Done%20and%20fixVersion%20in%20(5.3.0%2C%20%225.3.0%20Alpha%22%2C%20%225.3.0%20Beta1%22%2C%20%225.3.0%20RC1%22%2C%205.3.1%2C%205.3.2%2C%205.4.0%2C%20%225.4.0%20Alpha%22%2C%20%225.4.0%20Beta%22%2C%20%225.4.0%20RC%22)%20and%20priority%20in%20(%22P2%3A%20Important%22%2C%20%22P1%3A%20Critical%22%2C%20%22P0%3A%20Blocker%22)[over
70 important bugs] have been fixed in QtWebKit. For Debian Jessie (using Qt 5.3.2)
it's still
https://bugreports.qt.io/browse/QTBUG-42417?jql=component%20%3D%20WebKit%20and%20resolution%20%3D%20Done%20and%20fixVersion%20in%20(5.4.0%2C%20%225.4.0%20Alpha%22%2C%20%225.4.0%20Beta%22%2C%20%225.4.0%20RC%22)%20and%20priority%20in%20(%22P2%3A%20Important%22%2C%20%22P1%3A%20Critical%22%2C%20%22P0%3A%20Blocker%22)[nearly
20 important bugs].

When using QtWebEngine, qutebrowser reports "Render Process Crashed" and the console prints a traceback on Gentoo Linux or another Source-Based Distro::
    As stated in https://gcc.gnu.org/gcc-6/changes.html[GCC's Website] GCC 6 has introduced some optimizations that could break non-conforming codebases, like QtWebEngine. +
    As a workaround, you can disable the nullpointer check optimization by adding the -fno-delete-null-pointer-checks flag while compiling. +
    On gentoo, you just need to add it into your make.conf, like this: +
    
    CFLAGS="... -fno-delete-null-pointer-checks"
    CXXFLAGS="... -fno-delete-null-pointer-checks"
+
And then re-emerging qtwebengine with: +
    
    emerge -1 qtwebengine

My issue is not listed.::
    If you experience any segfaults or crashes, you can report the issue in
    https://github.com/qutebrowser/qutebrowser/issues[the issue tracker] or
    using the `:report` command.
    If you are reporting a segfault, make sure you read the
    link:doc/stacktrace.asciidoc[guide] on how to report them with all needed
    information.
