You click into a popular thread, ready to join in, and the top comment reads: “NGL, OP is right, this is peak r/mildlyinfuriating. TIL.” If that sentence felt like a foreign language, you are not alone. Reddit slang is its own dialect, built up over years by millions of people, and every subreddit adds a few words of its own. The good news is that the core vocabulary is small and easy to learn.
This glossary is your plain-English decoder. We will start with the single most-searched question, “what does OP mean,” then work through the core terms, the abbreviations, the culture words, and the content tags. Bookmark it, skim the table, and come back whenever a thread throws a new acronym at you.
Reddit Slang Quick Reference
Here are the 20 terms you will run into most often. Skim it now, then read on for examples of how each one is actually used in a thread.
| Term | Meaning |
|---|---|
| OP | Original poster, the person who started the thread |
| NSFW | Not safe for work, flags adult or graphic content |
| Karma | Your reputation score from upvotes |
| Cakeday | The anniversary of the day you joined Reddit |
| OC | Original content the poster made themselves |
| AMA | Ask Me Anything, an open Q&A thread |
| ELI5 | Explain Like I'm 5, ask for a simple answer |
| TIL | Today I Learned, sharing a surprising fact |
| TL;DR | Too Long; Didn't Read, a short summary |
| Crosspost | Sharing one post into another subreddit |
| Flair | A small tag next to a post or username |
| Mod | A moderator who enforces a subreddit's rules |
| Subreddit | A community focused on one topic (r/name) |
| Upvote | A vote that pushes content up |
| Downvote | A vote that pushes content down |
| Lurker | Someone who reads but rarely posts |
| Repost | Content already shared before |
| Throwaway | A temporary anonymous account |
| DAE | Does Anyone Else, asking if others relate |
| FTFY | Fixed That For You, a playful correction |
What Does OP Mean on Reddit?
OP stands for original poster, the person who created the thread you are reading. It can also stand for the original post itself, depending on context. Either way, when a comment mentions OP, it is pointing back to whoever started the discussion.
Say someone posts “My landlord kept my deposit, what are my options?” The replies will be full of OP. “OP, check your lease first.” “OP is right to be angry.” “Did OP ever update us?” In every case, OP is a quick way to talk to or about the person who opened the thread without typing out their username. When you are the one who made the post, congratulations: you are OP, and people will address you that way for as long as the thread stays active.
You will also see two related phrases. “OP delivered” is a badge of honor: it means the original poster came back and followed through on a promise, like sharing the photo or update they said they would. The opposite, when OP disappears and never responds, gets a lot of good-natured complaining in the comments. And when you edit your own post to add information, the convention is to mark it with “EDIT:” so readers know the text changed after people started replying. Small habits like these are what make you read as a real Redditor rather than a tourist.
Why Reddit Has Its Own Language
Reddit slang is not random. It grew out of two things: speed and belonging. Threads move fast and shorthand keeps replies quick, so “original poster” became OP and “Explain Like I'm 5” became ELI5. At the same time, knowing the words is a quiet signal that you actually belong here rather than dropping in to advertise. That is why using the lingo correctly earns goodwill and using it wrong, or not at all, marks you as an outsider.
The other thing to know is that every subreddit layers its own vocabulary on top of the site-wide basics. Investing communities have their own inside terms, gaming subreddits have theirs, and hobby communities invent words constantly. The glossary below covers the universal foundation. Once you have it, picking up any community's local dialect takes a day of lurking, not a month.
Core Reddit Terms Everyone Should Know
These are the building blocks. Learn these eight and you can follow almost any thread on the site.
Subreddit. A community built around one topic, written as r/name. r/cooking is for recipes, r/personalfinance is for money questions. Example: “This belongs in r/whatisthisthing, not here.”
Upvote and downvote. The arrows on every post and comment. An upvote pushes content up and signals it is good. A downvote pushes it down. Example: “Have an upvote, this made me laugh.” Some people even buy Reddit upvotes to give a new post early momentum before the crowd arrives.
Karma. Your reputation score, earned from the upvotes your posts and comments receive. It signals that a real, trusted person is behind the account. Example: “That reply farmed a ton of karma.” For the full story, see our guide to what Reddit karma is and how to build it.
Flair. A small tag attached to a post or a username. Post flair sorts content by category; user flair shows a role or a badge. Example: “Add the Serious flair so people know it is not a joke.”
Cakeday. The anniversary of the day you joined Reddit. A tiny slice-of-cake icon appears next to your name for the day. Example: “Happy cakeday, stranger.”
OC. Original content, meaning something the poster made themselves rather than reposting. Example: “Beautiful shot, is this OC?”
Crosspost. Sharing a post from one subreddit into another, with a link back to the source. Example: “Crossposting this from r/dataisbeautiful because you all need to see it.”
Mod. A moderator, a volunteer who enforces a subreddit's rules and removes content that breaks them. Example: “A mod locked the thread after it got heated.”
Reddit Abbreviations and Acronyms
Reddit runs on shorthand. These Reddit abbreviations and acronyms show up in titles and comments constantly, so here is the quick version of each.
- TIL means Today I Learned. It opens posts that share a surprising fact: “TIL octopuses have three hearts.” The entire r/todayilearned community is built around it.
- AMA means Ask Me Anything, a thread where someone with an interesting job or story takes open questions from the community. Some of Reddit's most famous moments have been celebrity and expert AMAs.
- ELI5 means Explain Like I'm 5. Use it when you want a genuinely simple answer stripped of jargon: “ELI5: how does a mortgage work?”
- TL;DR means Too Long; Didn't Read. Writers add a one-line TL;DR summary at the top or bottom of a long post so busy readers get the point without scrolling.
- DAE means Does Anyone Else, a way to ask if others share a quirk: “DAE hate the sound of styrofoam?”
- FTFY means Fixed That For You, a playful edit of someone's words to make a joke or a point.
- IIRC means If I Recall Correctly, a hedge before stating something from memory.
- NGL means Not Gonna Lie, used before an honest or slightly awkward opinion.
- IANAL means I Am Not A Lawyer, a disclaimer before someone offers legal-sounding advice. You will see the medical cousin, “not a doctor,” just as often.
- AFAIK means As Far As I Know, another soft hedge on a claim.
- IMO and IMHO mean In My Opinion and In My Humble Opinion, flagging that what follows is a personal take, not a fact.
- FWIW means For What It's Worth, a modest way to offer information you are not certain matters.
- ETA here means Edited To Add, not estimated time of arrival. It marks new information a poster tacked on after publishing.
- YMMV means Your Mileage May Vary, a reminder that what worked for one person might not work for you.
Reddit Culture and Community Slang
This is where Reddit gets its personality. These words describe how people behave, reward each other, and occasionally misbehave.
Lurker. Someone who reads constantly but rarely posts or comments. Most of Reddit is lurkers, and that is fine. Example: “Long-time lurker, first-time poster.”
Karma farming. Posting easy, crowd-pleasing content purely to rack up karma. Example: “Another cute puppy repost, classic karma farming.”
Repost. Content that has been posted before, sometimes many times. Example: “Nice repost, this hit the front page last year.”
Brigading. When a group from one community floods another to mass-downvote or argue. It is against the rules and gets accounts actioned.
Shadowban. A quiet restriction where your posts are hidden from everyone but you, with no notification. If your content is getting zero engagement, a Reddit shadowban checker tells you whether you have been silently filtered.
Throwaway account. A temporary, anonymous account made to ask a sensitive question without tying it to a main profile. Example: “On a throwaway for obvious reasons.”
Snoo. The friendly little alien mascot associated with Reddit. You will see the name in comments about the site's branding and avatars.
Gilded and awards. To be gilded once meant receiving a paid award on a standout post or comment. Awards have changed form over the years, but “take my upvote, I'm out of awards” still shows up as high praise.
“This.” A one-word comment meaning “I completely agree with the comment above.” Adding “underrated comment” is another way to signal that a reply deserves far more upvotes than it has.
A Few More Phrases You Will See Everywhere
These are not acronyms, but they are pure Reddit. Recognize them and the comment section stops feeling like an inside joke you are not part of.
Front page. The mix of top posts you see when you open Reddit, and shorthand for going viral. “This blew up, thanks for the front page” is what people say when a post takes off.
Hivemind. A gentle jab at the way a subreddit tends to agree on the same opinion and downvote anything outside it. “Careful, that goes against the hivemind.”
Circlejerk. A thread where everyone is piling on the same easy opinion for upvotes rather than saying anything new. Whole satire subreddits exist to mock the pattern.
Username checks out. A reply meaning someone's comment perfectly matches their username. It is one of the most upvoted one-liners on the site.
Source, or sauce. A request for proof or the origin of a claim or image. “Sauce?” is the fastest way to ask where something came from.
Sort by controversial. Reddit lets you reorder comments, and choosing “controversial” surfaces the most divisive replies. People mention it when a thread is about to get spicy.
Downvoted to oblivion. A comment so unpopular it collapses under a pile of downvotes. A close cousin of “this is going to get buried, but...”
NSFW and Content Tags Explained
NSFW means not safe for work. It is a tag on posts that are adult, graphic, or otherwise not something you want on your screen in public. Reddit blurs NSFW thumbnails until you choose to view them, which is exactly the point.
NSFL means not safe for life, a stronger warning reserved for genuinely disturbing or gory content. If you see it, take it seriously and scroll past unless you know what you are getting into.
Spoiler tags hide plot details behind a click so nobody gets a movie or game ruined by accident. In text, spoilers are wrapped so the words stay hidden until you tap them. These tags exist because Reddit communities police courtesy hard, and posting an untagged spoiler is a fast way to collect downvotes.
When you post, you are responsible for tagging your own content correctly. Marking something NSFW or as a spoiler when it should be is not just polite, it keeps your post from being removed by moderators and keeps your account in good standing. If you would rather not see mature content at all, Reddit's settings let you hide NSFW posts entirely, so the tags work in both directions: they protect the people posting and the people browsing.
New to Reddit? Start Here
Slang is only half the battle. If the mechanics of posting, commenting, and earning karma are still fuzzy, our beginner walkthrough on how Reddit works for beginners covers the whole flow from your first account to your first upvoted post. And once you are ready to actually participate, our roundup of the best subreddits to start in points you toward active communities where newcomers are welcome.
Frequently Asked Questions
What does OP mean on Reddit?
OP stands for original poster, the person who created the thread you are reading. When someone says "OP is right," they mean the person who started the discussion.
What does NSFW mean on Reddit?
NSFW means not safe for work. It flags content that is adult, graphic, or otherwise not something you want to open in public or at the office.
What is karma on Reddit?
Karma is the score you earn from upvotes on your posts and comments. It reflects how much the community has valued what you have shared.
What is a cakeday on Reddit?
Your cakeday is the anniversary of the day you joined Reddit. A small cake icon shows next to your username for 24 hours each year.
What does OC mean on Reddit?
OC means original content, something the poster made themselves instead of reposting it from somewhere else.
Keep This Handy
That is the working vocabulary. Once OP, karma, and the common abbreviations click, the rest of Reddit opens up fast, and every subreddit's little in-jokes start to make sense. Bookmark this Reddit slang glossary, skim the table when a new acronym trips you up, and jump into the conversation with confidence.