You need flags? Wikipedia commons has all the flags. This script will fetch them for you and write them out into a directory as scaled PNGs, assuming you have Node.js and whatever else is needed for this do run (look in package.json).
Here is the usage dump:
$ node flags.js --help
Scrape and serve or write Wikipedia flags as bitmaps.
Usage: node ./flags [options]
Some options must be provided, either --server or -w or -h.
Options:
-w, --width Maximum allowed image width [default: 1000]
-h, --height Maximum allowed image height [default: 1000]
--server Start a simple test server
-p, --port Server port [default: 8080]
--usage, --help Show usage
--lowercase Filename should be lower case. [default: false]
--filenames What flag property to use as a filename for each written
file.Available properties are "id" (name string), "iso2"
(ISO 3166-1 alpha-2 only), "iso3" (ISO 3166-1 alpha-3 only),
"fifa" (FIFA country codes), "ioc" (IOC country codes). Only
flags with corresponding properties will be output. Multiple
ID strings may be listed comma separated: "iso2,iso3" (try 2
char ISO, then 3 char, then ignore the flag).
[default: "id"]
If you're only testing things out you may want to use the server option. This runs a simple node HTTP-server that listens on the port of your choice and serves flag images as either the original SVG or as PNG.
You can ask for flags by a combination of properties: http://localhost:8080/[country name|flag].[svg|png]?[code]=[ID]
Some examples:
http://localhost:8080/flag.svg?ISO=fr
http://localhost:8080/flag.svg?IOC=fr
http://localhost:8080/flag.svg?FIFA=fr
http://localhost:8080/flag.svg?country=france
http://localhost:8080/flag.svg?country=france
http://localhost:8080/france.svg
http://localhost:8080/france.png?width=64&height=40
Warning: This assumes your usual developer "just read the code" know-how and should absolutely not be run as a production server.