this question is addressed widely on SO and outside it, but for some reason, instead of taking it as a good load of great advice, all this information is confusing me.

** Problem ** I already had, on one of my sites, "prettified" urls. I had taken out the query strings, rewritten the URLS, and the link was short enough for me, but had a problem: the ID of the item or post in the URL isn't good for users. One of the users asked is there's a way to get rid of numbers, and I thought it was better for users to just see a clue of the page content in the URL.

** Solution ** With this in mind, I am trying with a section of the site.Armed with 301 redirects, some parsing work, and a lot of patience, I have added the URL slugs to some blog entries, and the slug of the URL reports the title of the article (something close to http://example.com/my-news/terribly-boring-and-long-url-that-replaces-the-number-I-liked-so-much/

** Problems after Solution ** The problem, as I see it, is that now the URL of those blog articles is very descriptive for sure, but it is also impossible to remember. So, this brings me to the same issue I had with my previous problem: if numbers say nothing and can't be remembered, what's the use of these slugs? I prefer to see http://example.com/my-news/1/ than http://example.com/my-news/terribly-boring-and-long-url-that-replaces-the-number-I-liked-so-much/

To avoid forcing my user to memorize my URLS, I have added a script that finds the closest match to the URL you type, and redirects there. This is something I like, because the page now acts as a sort of little search engine, and users can play with the URLS to find articles.

** Open questions **

I still have some open questions, and don't seem to be able to find an answer, because answers tend to contradict one another.

1) How many characters should an URL ideally be long? I've read the magic number 115 and am sticking to that, but am not sure.

2) Is this really good for SEO? One of those blog articles I have redirected, with ID number in the URL and all, ranked second on Google. I've just found this question, and the answer seems to be consistent with what I think URL slug and SEO - structure (but see this other question with the opposite opinion)

3) To make a question with a specific example, would this URL risk to be penalized? Is it acceptable? Is it too long? StackOverflow seems to have comparably long URLs, but I'm not sure it's a winning strategy in my case. I just wanted to facilitate my users without running into Google's algorithms.