So many fact check reporters are out there. Most of them are biased. Worse, some themselves post fake news (Like Altnews.in; interestingly, they are IFCN qualified). Is there a standardized way to detect fake news?
There's no standardized way but there are a few well established ones.
And note that there are two hidden questions in your question. The first is: whether a piece of news is factual? The other one is: whether it's being spun as something it's not?
For the factual bit, a proxy is whether the piece of news got picked up by a well established news outlet. You're familiar with their names already. Think the Wall Street Journal, the Financial Times, the Economist, the New York Times, the New Yorker, the Washington Post, the Boston Globe, the Miami Herald, the Chicago Tribune, the LA Times, the SF Chronicle, Deutsche Welle, Le Monde, and so forth; as well as news agencies like AP, AFP, or Reuters. Pick two or three to be on the safe side and that should help you weed out non-factual stories and possibly true stories of dubious importance.
What these outlets have in common is that they tend to only report what they have fact checked. And when they're unable to fact check they make it explicit by distancing themselves with what's being reported. For instance, for a short while yesterday the Guardian was reporting that US media were reporting that Epstein committed suicide, and this was a clearcut sign that they hadn't fact checked it themselves yet.
Just to be clear, I don't mean here that reading those is a surefire way of never running into "news" stories that turn out false -- sometimes there's a blunder. When there is, you'll find a correction more often than not (except on Bloomberg). But for the most part they do their job properly.
Be wary, as you read those outfits, that opinion pieces are not reporting. And more generally speaking, never read opinion pieces as if they were factual, because more often than not they aren't.
For the spun bit, you're way ahead already if you stuck to the above news outfits and take opinion pieces with a giant fistful of salt. The key here is to understand that there are three types of articles in newspapers: news articles, analysis, and opinion pieces. In general (but not always), news articles are fact based and fact checked. Analysis builds on facts from news articles and spins it. Mind that there's a growing trend to mix analysis directly into news articles. vox.com epitomizes this trend, by literally encouraging their writers to not bother finding some expert for a quote just to spell out the bloody obvious and call a cat a cat. This trend may have contributed to lower trust in journalism; or maybe not -- I honestly don't know. Opinion pieces are, more often than not, spin that is loosely based on facts from news articles -- sometimes it masquerades as trying to connect the dots, sometimes it builds upon an anecdote and turns a molehill into a mountain, and so forth. As a rule you'll do well by not reading the opinion section of most newspapers if you're only interested in what's factual.
When all else fails, there's a number of fact checking websites and media bias references to look into if you really want to double check. Among the notorious fact checking websites: snopes.com, politifact.com, factcheck.org, etc. The two that repeatedly top searches when querying what a news source's bias is are mediabiasfactcheck.com and allsides.com
I think there are different ways: based on disproving content, based on analysing content of loads of messages, and based on how they are spread.
As the name says, it's fake, so proving it's fake is the obvious way to apply that label. How this is done depends on the type of fake news.
If a statement tries to present a fact, then it may be easy to point out why that's not true by making another factual statement supported by evidence.
If fake news pushes a narrative without presenting it as a fact then it's obviously harder. For example, you could write many bad reviews based on an experience which you exaggerated a lot, that's hard to verify.
Based on message content
This mostly applies to large scale fake news operations. For example, when you try to give a company a bad name by writing ten bad reviews, that probably won't be noticed if you present yourself with different identities and use different texts over a relatively long period of time.
In practice, those pushing fake news want to make an impact, for example to make something go viral. To make that happen, ten posts aren't enough. They may need tens of thousands of posts with different origins (i.e. supposedly different real people pushing them). To do that, they may use bot networks.
Another thing they'll need are different texts that push the desired message. If thousands of users of some platform suddenly post the same text (or one of a small batch), that'll be suspicious. They'll probably have to use some automated way to make posts or texts. Those can be detected and that's something scientists work on. For example in this paper: Fake News Early Detection: A Theory-driven Model. They do so by applying machine learning techniques on the content of messages.
Focusing on the accounts
Another technique focuses on the account used to push the message. As mentioned before, they need to push loads of messages to make something trending. For that, they need accounts, and you don't just get thousands of real people to play along. That, too, is something scientists look at. For example, in Supervised Machine Learning Bot Detection Techniques to Identify Social Twitter Bots.
The paper above looks at many factors (only in relation to Twitter), some of them (from table 2 in that paper), to give you an idea, are: description on profile, number of tweets, friends to followers ratio, has a custom profile image. And there are quote a few more.
Obviously, it's easier if you have access to the platform itself (i.e. the data Twitter has). As a company, they have access to where the tweets originate from (which i.p. address) and they can query many more tweets at once (most researchers / developers are limited to a fixed number of queries per minute).
Is the website it is on trustworthy?
If someone shares an article on a news outlet you haven't heard of yet, it might be useful to take a look at the frontpage. If all the articles appear to have a very obvious one-sided political slant or even go into conspiracy theory territory, you might be reading a fake-news or propaganda website.
Or it might even not be a news website at all, but a think tank or a political organization which published something which might read like a serious news article if seen out-of-context but is actually part of their agenda.
Is the headline phrased as a question?
If so, then the answer to that question is usually "maybe, but probably not". If the news outlet would be sure about something, they would phrase the headline as a statement. When a news headline is phrased as a question, then that usually means that the news outline is reporting on a rumor or makes an educated guess, but they have nothing to prove it.
Is it news or is it opinion?
Most news outlets publish two kinds of articles: "News" and "Opinion pieces". The first should be objective. The latter represent the personal opinion of a staff member or freelancer and will make an argument for that opinion to be right. Learn to tell the difference between these two. The first might be a reliable source, but the latter is not necessarily trustworthy because it will only mention the facts which support the author's opinion.
Who is the source?
A good news article should mention how the journalist learned about the information. The source of the information might tell you how reliable it is.
- If the source is a politician or political organization, keep in mind that the source has a political agenda and will only publish what furthers that agenda. Also, politicians are not universal experts on everything. If a politician talks about things they are not experts on, like psychology, civil engineering, warfare or meteorology, take what they say with a grain of salt.
- If the source is "scientists" or "a study", verify if the study actually says that. Journalists love to blow scientific findings out of proportion and tend to interpret conclusions into scientific publications which go far further than what the publication actually says. Also, keep in mind that the quality of scientific publications vary a lot. There is a lot of bad science which gets published because the author is under pressure to publish some results. It is often not easy for laypeople to tell good science apart from bad science. But a common sniff-test of bad science is a small sample size, lack of a control group, a sample which is not representative or results which are not really statistically significant. If you want to do more "research into research" see what other scientists in the field think about this. If they point out that the study conflicts with the findings of other studies which are based on far better data or if they mention that the author might not be qualified in that field, then the story might not be as reliable as it seems. But if other scientists are just as excited about the finding as the journalist, then there might be merit to it.
- If the source is "an expert" or "a witness", remember that humans are fallible. Experts might not actually be as knowledgeable as they pretend to be. Witnesses might remember things incorrectly or lie.
- If the source is unnamed, you should probably not pay much attention to this at all.
Is the information corroborated by other news outlets?
Be careful when there is only a single news outlet which reports something. When a news is really as big as they claim, others will also report on it. If you find other news reports about something, make sure that they actually have their own sources and are not just repeating what another news outlet reported.
General non-specific answer:
It's much like using reference books which have their various quirks.
Use fact checkers, but make allowances for the relative magnitudes of their various biases. That is, fact checker X might be good about topic A, but a little biased on B. Fact checker Y is objective about topic B, but highly partisan with regards to A. Fact checker Z is a crank about both topics, but is a meticulous critic whenever X or Y slip up.
Having more checkers, (however balky), to line up against each other adds value. Consider the precision engineering problem of making a really flat surface when you don't have any flat surfaces to start with:
Unlike most mechanical precision instruments, surfaces plates do not derive their precision from more-precise standards. Instead they originate precision by application of the principle of "automatic generation of gages". In this process, three approximately flat surfaces are progressively refined to precise flatness by manually rubbing them against each other in pairs with colouring matter in between, and then hand-scraping the high points. Any errors of flatness are removed by this scraping, since the only stable, mutually conjugate surface shape is a plane.
-- Surface Plane: History (WP)