encode.py (https://file.io)

encode.py

#! python3
import base64, binascii, json, urllib.request

s1 = 'Hello, World!'
code = base64.b64encode(binascii.hexlify(s1[::-1].encode('utf-8'))).decode('utf-8')
s2 = bytes.fromhex(base64.b64decode(code).decode('utf-8')).decode('utf-8')[::-1]
assert s1 == s2

link = json.loads(urllib.request.urlopen("https://file.io", data='text={}'.format(code).encode('utf-8')).read())['link']
link = base64.b64encode(link.encode('utf-8')).decode('utf-8')

# s3 = bytes.fromhex(base64.b64decode(urllib.request.urlopen(base64.b64decode(link).decode('utf-8')).read()).decode('utf-8')).decode('utf-8')[::-1]
# assert s1 == s3

print("python -c \"import urllib.request, base64; print(bytes.fromhex(base64.b64decode(urllib.request.urlopen(base64.b64decode('{}').decode('utf-8')).read()).decode('utf-8')).decode('utf-8')[::-1])\"".format(link))