TL;DR
Also called: TLDR, too long didn't read, tl dr
Definition
TL;DR stands for "too long, didn't read." On Reddit it labels a short summary of a long post or comment, usually placed at the top or bottom, so readers can get the main point without reading everything.
TL;DR means "too long; didn't read." Reddit's help center lists it among the top expressions for getting started and explains that someone who includes one is "offering a condensed version of the main points of the post" for readers who want the short version.
How it's used
- As a summary label. "TL;DR: switched from X to Y, saved $200/month, setup took a weekend." Most common at the end of a long post, increasingly at the top.
- As a request. "TL;DR?" in a reply means "summarize this, please."
- As a jab. Occasionally a reply that just says "tl;dr" means the reader gave up. That is feedback on length.
It is written TL;DR, TLDR or tl;dr. All are understood.
Why it matters for marketers
Reddit posts and comments about products are often long: setup stories, comparisons, postmortems. A TL;DR does three useful things:
- It respects the reader. People skimming a thread decide in a line or two whether to read more.
- It makes your point quotable. Other commenters and future readers can repeat a clear summary. So can search engines and AI answers, which tend to pull short, direct statements when they summarize or cite threads (see LLM citation).
- It forces you to have a point. If you cannot write the TL;DR, the comment probably wanders.
How to write a good one
- One to three sentences.
- Lead with the answer to OP's question, not with background.
- Include the concrete detail that matters: price, timeframe, team size, outcome.
- If you mention your own product, say so in the TL;DR too. Hiding the affiliation in paragraph six is worse.
Example
A founder writes a 600-word comment on migrating a small store off a big e-commerce platform. Without a summary it gets skimmed. With "TL;DR: moved 400 SKUs in two days, hosting costs dropped from $300 to $90/month, biggest pain was redirects (full list below). I run a migration tool, so weigh that accordingly." it gets read, quoted in two replies and upvoted to the top under Best.
Common mistakes
- A TL;DR that is a teaser ("TL;DR: read the whole thing"). It defeats the purpose.
- A TL;DR that is just a link. It looks like a drive-by pitch.
- Using TL;DR on a two-line comment. Short comments do not need one.
Frequently asked questions
What does TL;DR mean on Reddit?
"Too long; didn't read." It introduces a short summary of a longer post or comment, or asks someone to provide one.
Should the TL;DR go at the top or bottom?
Either works. Bottom is traditional; top is kinder to skimmers. In long how-to posts, many writers put it at the top.
Is TL;DR rude?
Writing your own TL;DR is polite. Replying "tl;dr" to someone else's post can come across as dismissive.