User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:65.0) Gecko/20100101 Firefox/65.0

Steps to reproduce:

Tried to filter errors in dev-tools error console to only messages that DON'T contain a string.

Actual results:

There isn't a way to do it. The documentation for Console messages states:

To see only messages that contain a specific string, type in the text box labeled "Filter output".

Expected results:

I should have more advanced options to filter error messages. In this case, I had a ton of harmless error messages that made it hard to find the meaningful ones, but didn't have a good way to filter out the ones I didn't care about.

In chrome you can use regular expressions to filter it, which allows you to accomplish this with negative lookahead.

Hello Thayne, thanks for reporting this issue!
It looks similar to Bug 1291192, so I'm going to set this one as a duplicate.
There's also a bug opened for regular expression filters (Bug 1441079).

Sounds good. I didn't find those when I searched for similar issues :(.

no worries, I had trouble finding it as well :D