You can view all the flags here: http://hjnilsson.github.io/country-flags/
This repository contains renders of all the worlds flags in SVG and PNG format.
The source files were taken from Wikipedia and are not under copyright protection since flags are effectively in public domain (there may be other restrictions on how the flag can be used though).
The flags are named by their 2-letter ISO-3166 country code, except for the constituent countries of Great Britain which have 6-letter codes "GB-ENG" etc).
Kosovo uses the user-assigned country code XK, which is not part of the ISO standard, but in use by several multinational organizations.
Also included is a JSON file that maps the ISO country code to the name of the country.
You can also install this as a NPM module:
npm install --save svg-country-flags
If you would like the flags in a different width than 100px, 250px or 1000px,
you can run the node script 'build-pngs', you must first install the modules svgexport and imagemin-cli:
npm install -g svgexport imagemin-cli
npm run build-pngs -- 1000:
Replace 1000: with whatever width you want (note the :), or type :200 to get
PNGs with a height of 200px.
If you cannot run the node script above, you can do the same steps manually.
Use a combination of svgexport and imagemin-cli from NPM to get that.
imagemin is very important because svgexport produces uncompressed PNGs which are several MB each.
Run the following commands in the svg/ directory to get PNGs of a desired width:
for file in *.svg; do svgexport $file "`basename $file svg`png" pad 1000: ; done
imagemin *.png --out-dir=../compressed-pngs/
rm *.png
The resultant files will be in the compressed-pngs folder. As before, 1000: is the dimensions to export.