SEO, 301s & backslashes at end of URL

[MSpencer]

Wordpess started adding "/" (slashes) at the end of my urls and I've left them up for some time.  Will removing them hurt search rankings or do I need to do a 301 redirect?

For example - www.site.com/page1/ changed to www.site.com/page1

Are there any other ramifications I may not be thinking about besides just search rankings.

[Malika1]

So does this mean that you can access the same content with and without '/' ?

This would mean duplicate content and duplicate content isnt really liked by Google. You can redirect these urls to the preferred one by using htaccess

There should only be one version live.

[MSpencer]

Will doing so have any impact on rankings or can I just make the full switch all at once without 301's.

[Mobilio]

So, this is HUGE technical SEO mess.

There are two chances - hosting or plugin:

1. Hosting - you can fix this with .htaccess quick. There are lot of examples in internet about adding or removing slash in end of url. You need to check and recheck your .htaccess or webserver configuration.
2. Plugin - sometime when WP update their plugins some of them comes with something more than bugfix or improvement. This is how they think "shouldn't hurt anybody", but in reality hurt ANYBODY because broke things. You need to try disable plugins one-by-one and see is this caused from them. This can be caused also from theme, WP itself and/or some custom code.

This is cause of problem. But fix is hard because you need evaluate approx time of chance. There are two cases:

1. If this happen soon you should fix it ASAP because for bots old pages are missing (you need to confirm that, please check, sometime they can 301 to new page).
2. If this happen few months ago and rankings wasn't lost then you can leave it in new format (do also .htaccess fix!). If rankings was lost then you can try to fix this (and also .htaccess fix!). It's difficult decision anyway.

As you can see everything dependent how long is this change and what damages already make. Try to see in SearchConsole more info about crawl and ranking.

I will save you little time with code for removing AND adding trailing slashes:
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)/$ /$1 [L,R=301]

RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^(.*[^/])$ /$1/ [L,R=301]

First code remove /, second code add / to urls. You also need to check canonicals, sitemaps and fix them according changes.

And one tip. You should always install in WP some plugin for backups. Period. You wasn't first nor last person in the world with situation "something happens". Of course one weekly backup cost you a penny and can save many hours of debugging or trying to fix things. There are many plugins in market with many different features so i can't give advise what will fit to your needs.

[MSpencer]

Thank you so much!