JavaScript regex multiline text between two tags

Solution 1:

You are looking for the /.../s modifier, also known as the dotall modifier. It forces the dot . to also match newlines, which it does not do by default.

The bad news is that it does not exist in JavaScript (it does as of ES2018, see below). The good news is that you can work around it by using a character class (e.g. \s) and its negation (\S) together, like this:

[\s\S]

So in your case the regex would become:

/<div class="box-content-5">[\s\S]*<h1>([^<]+?)<\/h1>/i

As of ES2018, JavaScript supports the s (dotAll) flag, so in a modern environment your regular expression could be as you wrote it, but with an s flag at the end (rather than m; m changes how ^ and $ work, not .):

/<div class="box-content-5">.*<h1>([^<]+?)<\/h1>/is

Solution 2:

You want the s (dotall) modifier, which apparently doesn't exist in Javascript - you can replace . with [\s\S] as suggested by @molf. The m (multiline) modifier makes ^ and $ match lines rather than the whole string.