Explaining ELI5 the ELI5 way, for anyone who wants to explain things clearly
No. 52Thinking ClearlyPart 10 of 12Fact-checked Oct 3, 2026Updated Oct 4, 2026
Video1:54 · Chinese audio, EN subs
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The full narration of the video.
ELI5 is just four letters. It means: explain it like I'm five. In July 2011, a forum opened on the American site Reddit with exactly that name. Someone asks, and everyone races to answer in plain words. Today it has more than twenty-three million members.
There are only four moves. One: no jargon. Two: compare it to something they already have at home. Three: let them see it first, then tell them its name.
Four: if you can draw it, don't write it. Big pictures, few words. Why keep it so simple? Because simple is the hardest test of whether you understand. In 2002, researchers at Yale ran an experiment. First, students rated themselves: how well do I understand everyday things, like a zipper?
Then they had to write it out, step by step. Asked again, they rated themselves lower. The physicist Richard Feynman hit the same wall. A colleague asked him a hard question. He said: I'll prepare a freshman lecture on it. A few days later he came back: I couldn't do it. If I can't bring it to freshman level, we don't really understand it.
So ELI5 doesn't treat you like a child. The forum's own rules say: answers are not aimed at literal five-year-olds. It wants two things: anyone can follow it, and it's still correct. Next time you explain something, start with something they already have at home. And wherever you get stuck, that's the part you haven't understood yet.
Oh, and one more thing: the video you just watched was an ELI5 too.
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In one line
Explain something so well that someone who knows nothing about it can follow.
ELI5 stands for "Explain Like I'm Five." It means: talk to me the way you'd talk to a five-year-old.
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Where it came from
On July 28, 2011, Reddit, a huge American online forum, opened a discussion board named "Explain Like I'm Five."
The rule is simple: someone asks a question, and everyone races to answer in plain words. Why is the sky blue? Where does money come from? Anything goes.
23 million+members (counted July 2026)
Soon the four letters "ELI5" spread everywhere, and online they came to mean "please, in plain English."
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How it differs from a usual answer
USUAL
"That's because of the so-and-so effect..."
Three words you've never heard, in one sentence. All you remember afterwards is that you didn't get it.
E L I 5
"It's like that thing in your kitchen..."
Start with a comparison to something you've already seen. Once you have a picture in your head, then you hear what it's called.
In short: a usual answer starts from the explainer's head. An ELI5 starts from the listener's head.
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Only four rules
① No jargonJargon is a shortcut for the speaker, not the listener. If you really must use it, explain it in plain words first.
② Use comparisonsCompare it to something already in their home. It has to be something everyone has seen.
③ See it firstGive them a picture in their head first, and only at the end say "this thing is called so-and-so." A name is just a label hung on the picture.
④ Big pictures, few wordsIf you can draw it, don't write it. With "big pictures, few words" as the rule, there's nowhere to hide fuzzy talk.
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Why keeping it simple is the hardest
Because simple explanations test whether you really understand.
The zipper study · 2002 · Yale
Feels like you get it, until you write it down
Researchers first asked students to rate how well they understood everyday things like zippers. Then they had them write out, step by step, how it works. Afterwards the students rated themselves again, and the scores dropped sharply. The researchers named this the "illusion of explanatory depth": the illusion that you understand more than you do.
The physicist Feynman's story
If you can't explain it to freshmen, you don't really get it yet
A colleague asked him about a hard physics problem. He said, "I'll prepare a freshman lecture on it." A few days later he came back and said, "I couldn't do it. I couldn't reduce it to the freshman level. That means we really don't understand it." That colleague later wrote the story into a book.
Two myths, busted on the way
The "Feynman Technique" wasn't named by Feynman.
The name was coined later by a writer on study methods, who himself says it only loosely follows Feynman's approach.
"If you can't explain it to a six-year-old, you don't understand it" wasn't said by Einstein.
It can't be found anywhere in his writings. The earliest source anyone has traced is a 2002 magazine.
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Two common misunderstandings
Not meant for actual five-year-oldsThe board's own rules say: "LI5 means friendly, simplified and layman-accessible explanations, not for responses aimed at literal five year olds." Talking to grown-ups as if they were toddlers just feels patronizing.
Not the same as inaccurateSimple means setting the details aside for now, not turning right into wrong. If a beginner can follow it and an expert can't find a mistake, you've done it well.
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What you're reading is an ELI5
One thing per screen
One picture for every idea
The only jargon is "ELI5," explained right at the start
The last line lands on you
Every page on this site, eli5.aisir.ai, explains one thing this way, and some come with a short video.
Next time you explain something, start by finding something that's already in their home.
If you get stuck halfway, don't blame the listener. The spot where you got stuck is the part you haven't figured out yourself.
