You paste a link into a tweet, a LinkedIn post, or a Discord message. Before you hit publish, a preview card appears: an image, a title, a line of description. Sometimes it looks great. Sometimes it pulls a blurry logo from seven years ago, a title written for a search engine, or nothing at all. You've probably wondered why that happens. The answer is Open Graph tags.
You don't need to know how to write code to understand them. You just need to know what they are, what they control, and why they so often work against you.
What Open Graph Tags Are
Open Graph is a protocol created by Facebook in 2010. The idea was simple: let website owners add a few lines of hidden HTML to their pages that tell social platforms exactly how to display a link preview. Those lines are called Open Graph tags, or OG tags for short.
They live in the head section of a webpage, the part of the code that browsers and crawlers read but don't display to visitors. A typical page might have a dozen of them. Most people who use the web every day have no idea they exist, even though they interact with the results of these tags constantly.
The Three Tags That Control Your Preview
Most of what you see in a social link preview is determined by three tags:
- og:title — the headline shown in the preview card, usually in bold
- og:description — the short paragraph below the title, if the platform shows one
- og:image — the image that appears in the card, often the most important element
There are others (og:url, og:type, og:site_name) but these three are what actually shape the impression a shared link makes. When all three are set correctly on a page, sharing that page should produce a clean, relevant preview card on most platforms. When any of them are missing, outdated, or just written for the wrong purpose, the preview breaks.
Why the Preview Rarely Shows What You'd Expect
The problem is that OG tags are set by whoever built the page, for their own reasons. A product page's og:title is usually optimized for search rankings, not for someone who just read your recommendation. An article's og:image might be the author's headshot, or a generic category banner. A company's homepage might have og:description copy that was last updated in 2021 and still mentions a product they discontinued.
Nobody writing OG tags is thinking about your specific post, your specific audience, or the context in which you plan to share the link. They're thinking about their brand, their SEO, and their homepage. The result is a preview that describes the page in generic terms rather than making the case for why your audience should click.
Affiliate and referral links are the worst case. A redirect URL like go.brand.com/ref/yourcode typically has no OG tags at all. The platform's crawler follows the redirect, hits the destination, and either renders whatever generic metadata it finds there or returns a blank card. A blank card in a social feed looks like a broken link. Most people won't click it.
Why You Can't Always Fix This at the Source
If you own the page, you can update its OG tags. Most website builders, CMS platforms, and blogging tools have a field somewhere labeled SEO settings or social preview where you can set them directly. If the preview looks wrong and you control the page, that's the right place to start.
But most of the time, you're sharing links to pages you don't own. A news article. A tool you're recommending. A product you're promoting. A partner's landing page. You cannot edit the HTML on someone else's site. You're stuck with whatever OG tags they've set, even if those tags produce a preview that actively works against your post.
Even when you do own the page, platform caching can undermine your changes. LinkedIn in particular is known for caching link previews aggressively. You can update your OG tags and share the link an hour later only to have LinkedIn serve its cached version from days ago. The fix exists (LinkedIn has a tool called the Post Inspector that forces a re-scrape) but it's an extra step most people don't know to take.
The Gap Between the Page and the Post
What OG tags really reveal is a gap between two different goals. The person who set the tags was optimizing for one thing: search, brand consistency, or a general visitor landing on the page directly. The person sharing the link has a different goal: getting a specific audience to click, in a specific context, for a specific reason.
That gap is where most social link performance is lost. The image doesn't match the tone of the post. The title describes the product instead of the outcome. The description is filler. The preview doesn't build on what you wrote in your caption; it just restates the page's generic positioning. You did the work of writing a good post, and the preview card undoes it.
How to Take Control
The way to close that gap is to put a layer between your shared link and the destination page: a hosted preview page that serves your custom OG tags to social crawlers, then transparently redirects real visitors to the original URL. The platform sees the title, description, and image you chose. The person clicking lands on the destination as if the preview page was never there.
This is what Prelinq does. You paste any destination URL, write the title and description that fit your post, and pick an image that will actually stop the scroll. Prelinq generates a link at prelinq.com that carries your metadata. Every platform that reads OG tags reads yours. You get the first impression you wrote, not the one the destination's developer set years ago.
You don't need to understand HTML to use it. The tags are still there, doing what they've always done. You've just taken back control of what's in them.