Following up on this post on internet filters, here are links to some free internet filters for computers:
For suggestions on filters for mobile devices, see this NY Times article: link
Of course, you should not think that installing a filter is sufficient, as discussed in the earlier post.
See prior freebies here: link
which one works without impeding speed?
OpenDNS will even increase your speed, its filter though is not particularly effective.
I’d qualify that comment about OpenDNS. I administer OpenDNS for the local day school, and I’ve found that OpenDNS can do a very good job of filtering IF you don’t mind going under the hood and doing a bit of homework. OpenDNS provides a “Dashboard” which allows the admin to see a log of URL’s which users (or machines) have tried to access; if you recognize in that list addresses related to banner ads, multimedia, etc., you can blacklist them on the spot. You can also find helpful info (like the URL’s used by Google Image Search and its ilk) in the OpenDNS Knowledge Base. Out of the box OpenDNS may seem inadequate, but after a break-in period I’ve found that it can be very effective.