Guide 04
How to Write a Good TL;DR
A TL;DR is one sentence that lets a reader skip everything else safely. How to write one, where to put it and what to leave out.
A good TL;DR is one sentence that lets a reader skip the rest without getting anything wrong. It states the main point or the decision, includes the one detail the reader needs to act, and leaves out the reasoning. If someone reads only your TL;DR and makes a choice based on it, that choice should be the same one they'd make after reading the whole thing.
That last test is stricter than it sounds, and it's what separates a useful TL;DR from a teaser.
Where the term comes from
TL;DR stands for "too long; didn't read." The Oxford English Dictionary traces it to a 2002 post on a Usenet video game newsgroup, where it was a complaint aimed at someone else's wall of text. Over time writers took it over and started adding their own TL;DR so nobody else had to ask. Oxford Dictionaries Online added it in 2013.
The tone has softened, but the job hasn't changed: respect the reader's time.
What goes in a TL;DR
A TL;DR answers one question: what does the reader need to know? For different kinds of text, that means different things.
| Text | The TL;DR should say |
|---|---|
| News article | What happened, to whom, and the key number or date |
| Study or report | The main finding with its scope ("in adults over 60") |
| How-to guide | The answer or the first action to take |
| Email or memo | The decision you need, by when |
| Opinion piece | The author's position, in one clause |
| Long social post or thread | The point you're building to |
Notice what's missing from every row: background, method, caveats that don't change the decision, and anything that starts with "In this article, I'll..."
Before and after
Here are a few made-up examples of a weak TL;DR and a stronger one.
A memo
Weak: "TL;DR: Some thoughts on our Q3 vendor situation and options going forward." Stronger: "TL;DR: Switch to the second vendor by Oct 15; it costs 8% more but cuts delivery time in half. Need your yes by Friday."
The weak version describes the memo. The strong one is the memo, compressed.
A news story
Weak: "TL;DR: Big changes coming to the city's recycling program." Stronger: "TL;DR: From January, the city will collect glass separately every other Tuesday; mixed bins with glass will be left at the curb."
A study
Weak: "TL;DR: Exercise is good for your brain." Stronger: "TL;DR: In a two-year trial of 400 adults over 65, a weekly walking group slowed memory decline slightly compared with a stretching group."
The stronger version is longer, and that's fine. Twenty-five useful words beat eight empty ones.
Rules that help
Lead with the verb or the finding
"Switch vendors", "Glass now collected separately", "Walking slowed decline". Readers scan the first three words.
Use the real number
"Costs 8% more" is a TL;DR. "Costs a bit more" is a shrug.
Keep scope words
"In adults over 65", "in a small trial", "for new customers". These are short, and dropping them is the easiest way to make a TL;DR wrong. Our guide to avoiding misleading summaries covers this in detail.
Don't tease
"TL;DR: you won't believe what we found" is a headline, not a summary. If the reader has to keep reading to learn the point, it isn't a TL;DR.
One sentence, two at most
If you need a list, call it "Key points" and keep the TL;DR above it as a single line.
Top or bottom?
Put it at the top when the reader is deciding something: whether to read on, whether to approve, whether the guide answers their question. This is the default for email, reports, announcements and long posts.
Put it at the bottom when the text is a story or an argument the reader expects to follow, and the TL;DR is a recap for people who scrolled to the end. Some writers put a summary in both places. That's fine, as long as they say the same thing.
A TL;DR for a shared article
When you share someone else's article, your TL;DR is a promise about what's in it. Write it from the body of the article, not the headline. Headlines oversell more often than the text does. Name the source, and if the piece is an opinion, say whose opinion it is.
The TweetSum summarizer gives you a one-line TL;DR alongside the post and key points. It takes the highest-scoring sentence in the article and trims it to your word limit, first by dropping asides and attribution tags, then by cutting at a clause boundary. You can set the limit between 8 and 30 words. Shorter isn't always better: if the trimmed line loses a qualifier, raise the limit or rewrite it yourself.
Writing the TL;DR last
Write the TL;DR after you've finished the rest. Drafting it first tends to lock you into what you meant to say, and the finished text often lands somewhere more specific. Read your conclusion, find its main sentence, and compress that.
Then read the TL;DR on its own and ask the test question again: if someone acted on this line alone, would they act correctly? If yes, you're done.
Questions
What does TL;DR stand for?
It stands for "too long; didn't read." It started as a slightly rude reply on internet forums and is now mostly used by writers themselves, as a label for a one-line summary at the top or bottom of a long post.
Should a TL;DR go at the top or the bottom?
At the top for anything people read to decide or act, such as emails, reports, announcements and long social posts. At the bottom works for stories and arguments where the reader expects to follow along and wants a recap.
How long should a TL;DR be?
One sentence, usually 10 to 25 words. If you need more than two sentences, you are writing an executive summary, which is fine, but label it as one.