How can I set default settings for htop?

htop has a setup screen, accessed via F2, that allows you to customize the top part of the display, including adding or removing a "Load average" field and setting it's style (text, bar, etc.).

These seem to be auto saved in $HOME/.config/htop/htoprc, which warns:

# Beware! This file is rewritten by htop when settings are changed in the interface.
# The parser is also very primitive, and not human-friendly.

I.e., edit that at your own risk. However, you should be able to transfer it from one system to another (version differences might occasionally cause a bit of an issue).

You could also set up a configuration, quit, and then copy the file, so that you could maintain a set of different configurations by swapping/symlinking whichever one with htoprc.

The easiest way is to use the setup in the program and then save and exit the program with F10, not with CTRL+C. Next time you can close the program the way you like.

Reset the settings in the config file

This are the default settings for htop on a Ubuntu 18.04 system. Replace the content of the file $HOME/.config/htop/htoprc and you should be fine. Make a backup first.

# Beware! This file is rewritten by htop when settings are changed in the interface.
# # The parser is also very primitive, and not human-friendly.
fields=0 48 17 18 38 39 40 2 46 47 49 1 
sort_key=1
sort_direction=1
hide_threads=0
hide_kernel_threads=1
hide_userland_threads=0
shadow_other_users=0
show_thread_names=0
show_program_path=1
highlight_base_name=0
highlight_megabytes=1
highlight_threads=1
tree_view=0
header_margin=1
detailed_cpu_time=0
cpu_count_from_zero=0
update_process_names=0
account_guest_in_cpu_meter=0
color_scheme=0
delay=15
left_meters=LeftCPUs Memory Swap 
left_meter_modes=1 1 1 
right_meters=RightCPUs Tasks LoadAverage Uptime 
right_meter_modes=1 2 2 2