Images can have a powerful effect on how people view the world. They can be used for propaganda, they can make or break the careers of politicians, influence opinion and even make people commit drastic actions. This is why it’s important to be sure an image is real.
Fake images goes back further than you would think. For as long as there has been photography, there has been fake imagery. The earliest cases of photography being manipulated stretch back to the 1860s. But since the invention of computers and the internet, false imagery has become ubiquitous. In 2010, Malaysian politician Jeffrey Wong Su En, produced a doctored photo of himself being knighted by the Queen of England, and in 2012 fake images of children wearing t-shirts spelling out ‘MONEY’ damaged Mitt Romney’s campaign for President.
The key to finding out whether an image is authentic is finding its original source. I’m going to do it with this image, which has since been debunked by Snopes.
1 Find the image
The easiest way is to do a Google image reverse search (this tool works best for articles and blog posts) by copying and pasting the URL into here.
By changing the search parameters to oldest or typing in specific words associated with the event depicted you should find the image on a reputable news or picture agency website. Once this happens you can assume it’s genuine.
2 Can’t find the image
Try narrowing your search by date. If you can’t find the picture you are looking for try doing an image reverse search with TinEye or Yandex (better for non English websites). For images you find on Reddit, use Karma Decay.
If you still can’t find the photograph try horizontally flipping it with a photo editor. Or use Flipapicture. When people create a fake picture they often start with a genuine image and then horizontally flip it before manipulation, so it’s harder to find in reverse image searches.
3 My image has a different caption which alters the context
The original caption of an image is normally different to subsequent versions but the meaning shouldn’t change. Be skeptical of accounts posting an image multiple times with exactly the same caption.
Someone may deliberately write an entirely new caption to alter the image’s meaning and use it to produce a made up story. This is how many fake news stories start. Check out Snopes example on how a photograph of Donald Trump lying on the floor, after participating in a wrestling match, has been used for various fake stories, such as him having a heart attack or being assassinated.
4 My image isn’t the same as the original
If you have found the image on a news or picture agency, but your version looks slightly different, then it may have been edited. Keep refining your search and putting in different search terms. Eventually you should find when the original image was first altered.
After the Charlottesville protests in America, an image of an anti-fascist protester hitting a police officer was circulated on social media, often accompanied by the claim that there was violence on both sides (white supremacists and counter protesters). In fact, this photograph was taken eight years ago, during riots in Athens, Greece in December 2009. After the violence in Charlottesville, it was digitally manipulated and an anti-fascist logo was added to one member.
You can also see whether something has been digitally altered by using Izitru. Users with more technical experience should try FotoForensics (Beware that it flags any photo not from a camera as suspicious).
5 What about videos?
If you want to reverse image search a video you can take individual stills and run them through an image reverse search, but this is both time consuming and there is no guarantee that the particular pictures will be found. Youtube Dataviewer extracts four thumbnails from any YouTube video and allows you to do a reverse image search much faster.
This guide was produced after Wikitribune interviewed Dan Evon, an image verifier expert from Snopes and Henk Van Ess, a fact-checking and image expert. Check out Henk’s latest medium post, “Inside the trenches of an information war” for more detailed advice on verifying images.