When comparing DuckDuckGo vs Pale Moon, the Slant community recommends Pale Moon for most people. In the question“What are the best browsers not based on Chromium?” Pale Moon is ranked 3rd while DuckDuckGo is ranked 14th. The most important reason people chose Pale Moon is:
"Classic" Firefox add-ons can work, but they are not supported and should be updated or forked to become a Pale Moon add-on.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Very protective of user privacy
DuckDuckGo does not collect or share any personal information. Their privacy page has a great rundown on why privacy is important. The most important repercussion of this is that DDG doesn't use the data collected to tailor results, avoiding exposure to the "Filter Bubble".
Pro Infinite scroll of search results
DuckDuckGo results page is an infinite scrolling page, so you don't need to be clicking through pages.
Pro Ads are non-obstructive and don't track you
The ads are clearly labelled as ads and are non-obstructive. The ads are based on the searched keywords and there's no tracking involved on their visibility. You just need to remember that the site the ad links to might track you.
Pro Can disable advertisements
The search engine allows freely disabling ads.
Pro Allows searching from specific sites using bangs
Bangs are commands that allow searching via a different website's local search engine, using keywords or abbreviations with an exclamation mark (!). For example searching "world war ii !wiki" will automatically redirect to Wikipedia.org and show results for the query "world war ii" there, instead of DuckDuckGo, using Wikipedia's search engine.
The more common sites have shortened alternatives for these commands. Such as !g for Google, !i for images and !yt Youtube.
The whole list of bangs can be found by typing "!bang" in DuckDuckGo.
Pro Has a wide spectrum of instant answers
For select queries DDG pops up a box that supplies the exact answer. For example, searching "stopwatch" will pop up a stopwatch, asking for "words like..." will show a list of related words, typing "password" will generate a password, etc.
Pro Many customization options for appearance
DDG allows customizing almost any aspect of the search engine's appearance including fonts, page width, alignment, header behavior, site icons, etc and has a selection of premade themes available as well.
Pro Lets you watch YouTube videos from the site
Duckduckgo lets you watch videos right from their site, so you can have more privacy than watching on youtube.com.
Pro Has a .onion site
Only accessible from Tor.

Pro Sometimes results are better than Google
Sometimes the search results are better. Most of the times, they're at least as good as.
Pro Has many fun features
For example, if you search "Color Picker" , you see a color picker.
Pro Can function without JavaScript
Of course, it's nicer when enabled, but it's not required. Some browsers are too limited (mobile, terminal) or turn it off for security reasons (tor, etc.), and DDG still works.
Pro Good for Linux users
DuckDuckGo has an API with some websites. With the help of this API, if you search for a fix of a problem in Linux, you can easily find an answer to the problem. For example, if you search for "How to update linux", you will get a message like this:
How to install updates via command line
Try this:
sudo apt-get update # Fetches the list of available updates
sudo apt-get upgrade # Strictly upgrades the current packages
sudo apt-get dist-upgrade # Installs updates (new ones)
--SirCharlo
Pro No filter bubble
DuckDuckGo does not filter your search’s with the data that they have. You get to see everything the Internet has to offer in a safe, private way.
Pro It's mainstream
This is the biggest private search engine there is
Pro Lets you go to other sites
You can go to the Wikipedia page for pigs by doing !w pig.
Pro Has its own add-on ecosystem, built on time-tested technologies such as XUL (plus JS and CSS) and XPCOM
"Classic" Firefox add-ons can work, but they are not supported and should be updated or forked to become a Pale Moon add-on.
Pro Designed for usability, not the shiny new things
Pro Light on resources, although it's not its main focus
Pro Independent from Google and Mozilla
Pale Moon is an independent fork of an older version of Firefox. Therefore, it is independent from Mozilla and are not affected by their terrible decisions such as removing XUL, adding telemetry, pocket, etc.
Pro Customizable
Pro Stable
Pro Support for existing web standards
Pro Respects your privacy
Contains much less spyware than Chrome and Firefox and all of it can easily be disabled.
Pro Open source
So we can verify that the browser is not spyware.
Pro Supports complete themes
Pale Moon supports complete themes, something which Firefox used to have before version 57.
Pro Support for GTK themes
Pale Moon supports your GTK theme while Firefox does not.
Pro Uses Goanna layout engine
Unlike most other browsers, Pale Moon uses its custom engine.
Pro Has its own library of legacy extensions
Pro Very Independent
It isn't controlled by Google nor Mozilla, has its own engine.
Pro Good community support
Pro Optimized for modern processors
Pro Legacy Firefox
Cons
Con No date information in search results
In search results, there are no dates when the pages were published, which doesn't allow you to immediately know if the page is outdated.
Con Downranks misinformation results
Company announced that they are downranking misinformation results about the war by Russia media, after Russian's invasion of Ukraine.
Con Irrelevant search results
They store no information about you (theoretically a pro) but this results in absolutely awful search results, and having to modify your search terms 4-5 times to get what you are looking for.
Con Owner would compromise his service/customer privacy
In a question to Weinberg, “if you were served an NSL or were commanded to compromise your service/customer privacy in any way, would you and could you just pull the plug like Lavabit did or would you run into opposition from shareholders/investors that would prevent you from doing so?” Gabriel Weinberg said: “No one is preventing me from doing that.”

Con Still not better than Google
Results are quite often not as good. They just lack resources to do it, for now.
Con Based in US, so they cannot guarantee there is no backdoor
Con DuckDuckGo has no 3rd party certifications
Con Activism censorship
They started to block results based on activism.
Con Search using language other than English is not so great
Korean would never use it.
Con Referrers
A referrer is an HTTP header field that identifies the address of the webpage (i.e. the URI or IRI) that linked to the resource being requested. By checking the referrer, the new webpage can see where the request originated.” Basically it tells a website where you came from. DDG does give this out.
Con Bing = DuckDuckGo
Duckduckgo depends on Bing for the query.
Con Search results are often unrelated and limited
Common conversions do not work, i.e. searching for 15F to C does not give you the conversion but just a bunch of conversion websites. Very frustrating. It's a simple thing but makes a huge difference to the browsing/searching experience. Also location based only works for the country you're in. Searching for, say, McDonalds only gives country results for McDonalds and no local results such as where a local restaurant may be. Not very helpful.
Con DuckDuckGo has many 'Owners'
DuckDuckGo is owned by Gabriel Weinberg who is is the founder, current CEO and controlling shareholder. Investors/shareholders include Union Square Ventures and several others. DuckDuckGo generates its income from advertising (Bing Ads) and collects affiliate revenue (Amazon, eBay).

Con Needs a clearer vision of the future
What's duck's goal or quest?
Con Shows too few images
When searching for images only, it shows too few of them and only a handful are related to the search terms.
Con Hosted on Amazon servers (EC2)
Con Bangs do not protect user privacy and can be misleading
Using these bangs will instantly connect you to the service you requested. For example typing “!g white cat with green eyes” and hitting return, drops you off on the Google website to display your results (thus logging your IP, search term and browser info immediately). It does not get you Google results inside DuckDuckGo. It is reasonable for DDG users to assume and expect a private search engine warns if there is a risk to that privacy being lost, like it does with Youtube videos but in the case of Bangs this does not happen.
Con Saving settings in Duckduckgo's Cloud still needs improvement
Cloud save and the ability to pull up your settings on any device is a nice idea but the implementation needs work.
Con Doesn't do personalized searches
Since they don't track you the results are not tailored to your interests.
Con Form over function (overall search experience is poor)
It's nice to adjust the settings and all but after a couple of days you will want to go back to a more functional search engine.
Sure DDG looks shiny and !bangs are great but many wouldn't consider it as a viable alternative. Better results for search queries is more important than fancy looking CSS.
Con Unsecure
Pale Moon lacks the sandboxing and other privacy protecting features included in latest Firefox releases.
Con Still contains some spyware
Default homepage is spyware and search suggestions and automatic updates are enabled by default.
Con Outdated rendering engine
It is an really old fork of Gecko that misses many of the newer web features.
Con Pale Moon is based on very outdated Firefox code
Con Uses Goanna
It an old Gecko-fork that is developed mainly by one man.
Con Lacks popular extensions and adblockers
It doesn't have ublock origin and umatrix.
Con Does not contain multi-process sandboxing
Con Android version has odd behavior
Clicking does not work.
Con Pale Moon's website is cloudflared
Con WebAssembly enabled by default
Con Lead developer loves Cloudflare and hates Tor
Website is cloudflared and he thinks most sites should be hostile towards tor.
Con Incompetent developers
