Is it ok to remove newline in Base64 encoding

Some of the Base64 encoders append EOL characters like CRLF ('\r\n') to the encoded strings. You can use Base64.encodeBase64URLSafe to get rid of them:

Encodes binary data using a URL-safe variation of the base64 algorithm but does not chunk the output. The url-safe variation emits - and _ instead of + and / characters. Note: no padding is added.

Breaking a base64 encoded string into multiple lines has been necessary for many old programs that couldn't handle long lines. Programs written in Java can usually handle long lines since they don't need to do the memory management themselves. As long as your lines are shorter than 64 million characters there should be no problem.

And since you don't need the newlines, you shouldn't generate them at all, if possible.