# Frequently asked questions

The Compiler
`<mail@qutebrowser.org>`

1. What is qutebrowser based on?

   qutebrowser uses Python, Qt and PyQt.

   The concept of it is largely inspired by dwb and Vimperator. Many actions and key bindings are similar to dwb.

2. 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 Qt/PyQt.

   Read the next few questions to find out why I was unhappy with existing software.

3. What’s wrong with dwb/vimprobable/luakit/jumanji/… (projects based on WebKitGTK)?

   Most of them are based on the WebKitGTK+ WebKit1 API, which causes a lot of crashes. As the GTK API using WebKit1 is deprecated, these bugs are never going to be fixed.

   The newer 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 uzbl).

   qutebrowser uses Qt and QtWebKit instead, which suffers from far less such crashes. It might switch to QtWebEngine in the future, which is based on Google’s Blink rendering engine.

4. What’s wrong with Firefox and Pentadactyl/Vimperator?

   Firefox likes to break compatibility with addons on each upgrade, gets slower and more bloated with every upgrade, and has some horrible ideas lately.

   Also, developing addons for it is a nightmare.

5. What’s wrong with Chromium and 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.

6. Why Python?

   I enjoy writing Python since 2011, which made it one of the possible choices. I wanted to use Qt because of QtWebKit so I didn’t have many other choices. I don’t like C++ and can’t write it very well, so that wasn’t an alternative.

7. But isn’t Python too slow for a browser?

   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 GIL released.

8. Is there an adblocker?

   There is a host-based adblocker which takes /etc/hosts-like lists. A "real" adblocker has a big impact on browsing speed and RAM usage, so implementing it properly might take some time and won’t be done for v0.1 if at all.

9. 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. 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}

10. How do I use qutebrowser with mutt?

    Due to a Qt limitation, local files without `.html` extensions are "downloaded" instead of displayed, see #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;

## 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 allow-plugins true` in qutebrowser will enable plugins. Packages for flash should be provided for your platform or it can be obtained from 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 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 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 INSTALL.

  Since Ubuntu Trusty (using Qt 5.2.1), over 70 important bugs have been fixed in QtWebKit. For Debian Jessie (using Qt 5.3.2) it’s still nearly 20 important bugs.

My issue is not listed.

  If you experience any segfaults or crashes, you can report the issue in the issue tracker or using the `:report` command. If you are reporting a segfault, make sure you read the guide on how to report them with all needed information.