Should I replace underscores in page file names with hyphens?

[lbohen]

Many of the 1000s of pages at our Web store that were established several years ago but still relevant today have underscores separating words in page file names. For example: http://www.audiobooksonline.com/whats_new_compact_disc_audiobooks_audio_books.html

Should I replace the underscores with hyphens like this:

http://www.audiobooksonline.com/whats-new-compact-disc-audiobooks-audio-books.html

or should I duplicate pages with underscores using hyphens and have the older pages with underscores 304 re-directed to the new pages with hyphens?

[EricPratum30]

Check out the attached video.

If it were me, I would look at the link profile of the pages that could potentially change and, assuming I didn't find something that told me to just keep it as is, I'd make the change and then 301 all of the underscored URLs to the rewritten URLs.

watch?v=Q3SFVfDIS5k

[Cyrus-Shepard]

Hi Larry,

Truth be told - I would leave them alone.

It's true that Google treats underscores differently than dashes - or at least they did as recently as 2011. In this Webmaster Video, Matt Cutts explains that underscores act as a "joiner" - joining the two words together.

http://www.youtube.com/watch?feature=player_embedded&v=AQcSFsQyct8

But he also states that it's a minor effect, that's it's not worth changing if you don't have to.

I happen to agree with Matt on this. Changing your urls and/or redirecting them usually doesn't cause much problems, but in certain cases it can have a negative effect on your SEO, resulting in a loss of traffic and rankings. We generally advise folks not to change your URLs unless you have to - and in this case you don't have to.

CAVEAT: The only situation I would actually advise you to make this change is if you were overhauling your website/CMS and had to change your URL structure anyway. In this situation it would make sense, and you would want to redirect the old URLs via 301 to the new structure.

Hope this helps! Best of luck with your SEO.

[Cyrus-Shepard]

Shoot, I just realized I linked to the same video. Thumbs up for that.

[EricPratum30]

No worries. And, I agree with you on the drawbacks. I know I've made changes like this before and caused more problems than I think I had in the first place