How it works
The simple idea behind the method, plus the research that supports it. The tool doesn't tell you what to believe. It helps you investigate for yourself.
The core idea
Most people read vertically: they stay on a page and judge it from the inside.
They look at the logo, the confident tone, the trustworthy-sounding domain. This is exactly what a misleading source is built to survive. Official-looking design, scientific-sounding language, and a .org address are all cheap to fake, and they're aimed precisely at the reader who's trying to be careful.
Professional fact-checkers do something different. They read laterally: they leave the page almost immediately and open new tabs to see what the rest of the web says about the source and the claim. They don't waste time evaluating an unfamiliar source from within. They get out and check it from outside.
This companion is that habit, made easy. It never grades the claim for you. It routes you, fast, to the places where you can judge it yourself, and it does that in tiers so you rarely have to do much work at all.
The routing
≈ 1 second · automatic
Before you do anything, the tool searches a database of published fact-checks, the aggregated work of outlets like Snopes, PolitiFact, and dozens of others worldwide. If professionals have already looked at your claim, their findings appear at once.
"Someone already checked this" is the fastest possible answer, and a large share of everyday claims can resolve right here with no effort from you.
≈ 10 seconds · one question
If nothing's on file, the tool skips the checklist and asks the single most useful thing a fact-checker asks first: do you recognize who's behind this, and would they benefit from you believing it?
A loud source that profits from the very claim it's making is the oldest red flag there is. For a surprising number of claims, sitting with that one question is genuinely enough to make an informed call.
Only if you want it
When a claim truly warrants a closer look, the deep dive walks the three classic moves, with searches pre-built so you click instead of type: who is behind it, where it originated, and who else is covering it.
This is the real skill, offered on demand rather than forced on every claim by default. It's the same flow the browser extension runs.
Watch it run once
You understand a process best by watching it run once. Here's a single claim moving through all three tiers.
"New study says this one common food doubles your risk of heart disease."
The scan finds a related fact-check: one outlet rated a near-identical headline Missing Context. That's already a signal, in about a second, that the framing is contested, before you've read a word of the article.
Who's behind it? The claim traces back to a supplement retailer's blog, and they'd benefit from you distrusting an ordinary food. That's the reflex firing: the loudest source is the one that profits from the claim.
Dig deeper and the "study" turns out to be a conference abstract, not a peer-reviewed paper. "Doubles your risk" means going from 2% to 4%, a two percentage-point change dressed up as alarming. And two other major outlets never covered it at all, so the convergence that would make it credible simply isn't there.
At no point did the tool say true or false. You worked it out yourself, and you now know exactly why you'd hold this one loosely. Total time: under two minutes.
What it won't do
It never tells you a claim is true or false, and never gives a credibility score. A rating you don't understand is just one more thing to take on faith, and this tool exists to do the opposite.
It coaches you to cross-check across independent sources, but it doesn't decide which institutions you should trust. That judgment stays yours.
The point of checking quickly is knowing what to ignore, so your attention goes to what deserves it. A quick exit is a win, not a failure.
What you check isn't logged, sold, or kept. The analysis happens, and then it's gone. No accounts, no tracking.
The study behind it
The whole approach traces back to a 2019 study by Sam Wineburg and Sarah McGrew that gave a name to the skill this tool teaches. They sat 45 people down in front of unfamiliar websites and asked them to judge how trustworthy each one was: 10 professional fact-checkers, 10 PhD historians, and 25 Stanford undergraduates. Everyone thought aloud while a screen recorder captured every click.
The historians and the students, all obviously capable readers, mostly stayed on the page and sized it up from the inside: the logo, the tidy layout, the .org in the address, the references at the bottom, the "MD" after an author's name. And that's exactly how they got fooled. In one task, a fringe advocacy group with an official-looking site was judged more reliable than the largest pediatric association in the world, because its page simply looked the part. Polished design and scientific-sounding language turned out to be trivially easy to fake.
Two more habits separated the checkers from everyone else, and both are built into this tool. They took bearings before diving in: get a sense of where you've landed before you start reading closely. And they practiced click restraint, scanning the whole search-results page and reading the snippets before clicking anything, rather than trusting the top result. The headline finding is almost paradoxical: the experts read less and learned more. They ignored most of the page on purpose, which freed them to spend their attention on the few things that actually revealed who was behind it.
That's the entire idea this tool is built to make effortless. You don't need to become a professional fact-checker. You just need the one move they all make: get off the page and look around.
The short version
If you remember nothing else, remember these four moves. They're the method in a single word, and they're the order the tool walks you through.
See whether someone has already fact-checked this. Half the time, that's the whole job.
Who's behind this, and would they benefit from you believing it? The single most useful question.
Are independent outlets saying the same thing? Agreement between sources that have no reason to agree is what counts.
Still unsure? Leave the page and trace the claim back to where it started. That's lateral reading in one move.
The evidence
The method is built on decades of research into how people evaluate information, why we get misled, and what strategies help us make better judgments. Below are some of the key papers behind the approach, with plain-language summaries where I've written them.
Lateral reading and the nature of expertise
The study summarized above: fact-checkers, historians, and Stanford students evaluate unfamiliar sites. The checkers read laterally, and reached sounder conclusions in a fraction of the time.
Critical ignoring as a core competence for the digital age
Argues that in an attention economy, knowing what to not read is as important as knowing what to read. Lateral reading is one of the three core "critical ignoring" skills. This is the paper the whole IgnoreMore idea grows out of.
Lateral reading on the open Internet: a district-wide field study
Proof the skill is teachable, not just an expert quirk. Across an entire urban school district, six 50-minute lessons in lateral reading significantly improved students' ability to judge real online sources on the live web. The moves those lessons taught, investigate the source, use click restraint, leave the page, are the same moves this tool walks you through on every check.
Boosting media literacy using lateral reading and online search interventions
A nationally representative trial in Germany that shaped this tool's design directly. Lateral reading worked mainly by lowering trust in unreliable sources, while searching for evidence worked mainly by raising trust in reliable ones, and neither backfired. It's why the tool coaches what a good sign looks like at every step, not just red flags: the goal is discernment, not blanket distrust. It also found brief interventions have modest effects on their own, which is exactly why this lives in your browser for repeated practice instead of being a one-time lesson.
Want the fuller version? I write about all of this on the Misguided newsletter, and it's the subject of my book, Misguided.