I have been using Mojeek.com privacy search engine for about 3 weeks as my daily driver on all laptops. Most of my initial thoughts have turned out to be right.
I used Mojeek just as hard as I did Qwant and all the other search engines. There were many times where I was adjusting my search terminology to refine my results. Unlike Qwant, I was never mistaken for a robot in the middle of important work and challenged to prove I was human. Mojeek gave me what it had every time, no time outs, no challenges to my humanity.
Mojeek has an optional feature for Emotional Search. I did not use this, and I really do not care about it.
The search engine has one of the most uncluttered SERP of any search engine: no ads, no trying to lure you to onsite portal features, no product placement, just straight up search results with appropriate Wikipedia articles linked to in the right hand column.
The Mojeek algorithm seems pretty darn good. I do know that the algo uses both on-page and off-page (linking) factors for ranking which is exactly what you would expect for any modern crawling search engine. Only Mojeek knows exactly how these are applied.
I do a lot of certain types of searches: Navigational searches and review, comparison type searches. Navigational searches are where I know the site I want, but I’m unsure of the domain name: (eg: was it FOMOCO, Ford Motors, Ford Cars, ford.com?) Review comparison searches (eg. “best free email client for Windows 10,” “best notes software for linux 2018”)
However, the size of the index does come into play. Sometimes the topic is so obscure that Mojeek just didn’t have either very many results or not enough good results. This is when I would try to phrase my search a different way. Mostly that didn’t work.
Long complex multi keyword searches often came up with very few results. Again this is just index size. Mojeek understood the complex search, it just didn’t have much that fit all the keywords.
I would say about 70 percent of the time, in daily default use, Mojeek gave me something useful. Sometimes it dug up gems that Google or Bing fed search engines would have buried on page 4 or more. And it was because of those gems, that I really didn’t mind using Mojeek as my primary search engine. If it failed I could easily run the same search on another engine for backup. All said, this test with Mojeek was more fun than annoying.
Actually, the more I used Mojeek the more I came to respect it. Working with only their own index and algo is like performing a high wire act without a net. You don’t have that feed from Google or Bing as a safety net to back you up. I kind of looked forward to seeing what it would bring up, but that is just me, YMMV.
I don’t think most mainstream people will use Mojeek yet as their primary search engine but I do think, right now, it is a good second search engine, for when you are tired of seeing the same domains dominating your search results, you can pop over to Mojeek and find other voices. I still wish I could code a parallel search form with DDG and Mojeek on it, I would use that every day and have the best of both worlds.
UPDATE: 22 March 2019
Per Mojeek: The current index is 2.3 billion pages. They hope to double that in 2019 and double that again in 2020. That will help to address many of the weaknesses I noted in the above review. Good news. Source