This setting is now a little hard to find in the GUI since it is not explicitly labeled.
Click on the icon view button to bring up settings dialog; then move the slider to the left to change the icon size to small.
You can find the same setting in
org >> gnome >> >> nautilus >> icon-view >> default-zoom-level: [small, standard, large]
There is also a
thumbnail-size setting that is supposed to work along with the
small setting; but nautilus does not seem to follow this setting and it did not have an effect. You may want to file a bug report.
Going below 48px requires changing the Nautilus source code and recompiling. (Yes, they hard-coded icons sizes.)
INSTRUCTIONS FOR NAUTILUS 3.20.4 ON UBUNTU GNOME 17.04
Install the following dependencies:
libgd-dev autotools-dev libexif-dev libexempi-dev libselinux1-dev libtracker-sparql-1.0-dev libext-dev libxml2-dev libgnome-desktop-3-dev
Each one installs a bunch of other stuff, so hopefully I've given you the correct parent package name. I apologize for not recalling with 100% accuracy exactly what I installed, but this looks fairly correct to me immediately after my install. (Notify me if I'm inaccurate anywhere.)
Download from the Nautilus snapshots website the version of Nautilus that you are currently using. To find that out, run
nautilus --versionfrom the terminal. After downloading the archive, unzip it to whatever directory you want to work from.
From within the unzipped package, open the file
nautilus-icon-info.h. Within the first several lines you will see various sizes designated for the particular scroll-setting options. For instance, within the file for version 3.20.4 the icon sizes start on line 36. Change each of those levels to whatever you want to use so that you can make the icons much smaller (or larger).
After editing and saving the file, it's time to configure, compile, and install. Run the following commands from the terminal from within the base directory of the version of nautilus that you have downloaded and unzipped. Make sure that you are within the base of the folder structure of the nautilus directories!
./configure make sudo make install
These can be run altogether with the command
./configure && make && make install
./configure command fails it's because you are missing some other dependencies. I apologize if my list of dependencies above was incomplete. Google (or whatever search engine you want) to find what package it is that you need. You can use Synaptic to search for what you need if you're unsure even after Googling.
Once installed, I suggest a reboot just to make sure that every single thing is reloaded properly. You can now tweak with your icon sizes as you wish.
According to this Google+ post, starting from Nautilus 3.15, it seem that the "small" icon size 64, is the smallest option available (so the new "zoom" slider will not work as intended).
More details in this GNOME Git commit.
There are more informations and some are misleading. Also, I found somewhere on GNOME bugs a mention that it will not be fixed as the decision was taken as temporary solution for a bug elsewhere.
At this moment the only solution (not tested) seem to be rebuild of nautilus using different icon size for "small". Or "downgrade" if possible.
I have exactly the same problem. At least for the Desktop icons this tutorial worked for me, maybe it helps somebody else aswell:
It uses "Tweaks", which I had already installed. Then I had to install the "GNOME shell integration" Add-on in Firefox and "Desktop Icons" by rastersoft (https://extensions.gnome.org/extension/1465/desktop-icons/) as extension.
In my case the preferences of "Desktop Icons" were at: ~/.local/share/gnome-shell/extensions/desktop-icons@csoriano/prefs.js
instead of /usr/share/gnome-shell/extensions/desktop-icons@csoriano/prefs.js. In case you already had desktop icons before the extension, you can disable them in Tweaks -> Desktop -> Show Icons.