Every link you post on X turns into a t.co URL that occupies exactly 23 of your 280 characters, and the preview card beneath it is built from page metadata most people never check. Both are decided before you press Post.
How do you preview a link before you tweet it?
Paste the URL into Circleboom's free Twitter Card Validator, which fetches the page's metadata and renders a tweet-style preview of your card on X through official X API access. Type your post text beside the card, watch the live 280-character counter, and publish only when the whole tweet looks right.
→ Preview a link before you tweet it
Why Does Your Link Look Broken on X After You Post It?
X never shows the raw link you pasted. The platform reads your page's Open Graph and Twitter Card tags, builds a preview card from them, and displays that card in the timeline.
When those tags are missing or stale, the card comes back with no image, or with a title that describes an older version of the page.
The timing is what stings. You discover the broken card only after the tweet is live, once it has already reached the followers who see your posts first.
Deleting and reposting resets replies and reposts to zero, so the mistake costs you the audience that engages earliest.
The reliable defense is to preview a link before you tweet it, while the card is still private. Circleboom renders your link's card for X ahead of publishing, using approved API access.
You can check how your link will look before you tweet it in about a minute, no account required.
More than looks is on the line. The card is the largest clickable surface in a link post, and its image and title decide whether a scroller stops.
If you have ever checked how many times a link was clicked on Twitter, the card is usually the variable that moved the number.
What Circleboom's Twitter Card Validator Shows You
Circleboom's Twitter Card Validator is a free public tool that displays a URL as X will render it. Paste the link, click CHECK PREVIEW, and the right side of the page fills with a tweet-style preview built from the metadata your page actually serves.
That preview carries every element the timeline will show:
- The account avatar and display name, as the tweet's author context.
- The URL, written as it will appear inside the post.
- The card image pulled from your page's metadata.
- The card title, rendered as the caption on the card.
- A live character counter tracking the 280-character limit.
The caption under the image comes from your page title or the Twitter Card title in your metadata. When the preview shows a stale headline, that tag is the one to edit.
The data source is the part worth trusting. Circleboom is an official X Enterprise Developer, so the card check runs on official access rather than scraping.
Nothing about it touches your account, and it posts nothing on your behalf.
Run your next campaign URL through the tool and preview how a link will look in a tweet while the page behind it is still easy to fix.
For the longer treatment of card formats and setup, the Twitter Card Validator guide on the Circleboom blog goes deeper than this walkthrough needs to.
Validate the Whole Tweet, Not Just the Card
Most metadata checkers stop at the card. Circleboom renders the post itself, with the author context up top and the card sitting beneath your text, laid out the way followers will meet it in the timeline.
The text area is where that difference earns its keep. Type your draft copy beside the card and a live counter measures everything against the 280-character limit, so a reading like 64 / 280 tells you at a glance how much room the link and your opening line have used.
You publish a tweet, not a card, so the preview should show the tweet.
The manual alternative is publishing a test post from a spare account and deleting it once you have seen the card, which still shows the broken version to anyone watching and leaves a deleted post behind. The validator answers the same question with nothing published.
The counter matters because X does its own math on links. Every URL is wrapped by the platform's t.co service and counts as 23 characters no matter how long the original address runs.
The rule is laid out in the X link shortener documentation. Subtract that from 280 and your message has 257 characters to work with, arithmetic the preview handles for you as you type.
Character budgeting on X has more wrinkles than people expect. The breakdown of how many characters can you use on Twitter (X) covers the limits by account type when you want the full picture.
How to Preview a Link Before You Tweet It
To preview a link before you tweet it, paste the URL into Circleboom's free Twitter Card Validator, render the card, then compose your post text beside it until the preview and the counter both look right. The check runs in any browser with no login required.
Six short steps, grouped into two passes.
Render the card preview
- Open the Twitter Card Validator page in your browser. The tool is public, so there is no login and no password step.
- Paste the URL you plan to share into the input field marked with a link icon.
- Click CHECK PREVIEW and let Circleboom fetch the page's metadata and draw the tweet-style preview on the right side of the screen.
Compose the tweet and fix what the preview exposes
- Type your post text in the preview area so the message and the card appear together in one view.
- Watch the character counter while you write; it weighs your text and the 23-character link against the 280 limit as you type.
- Review the card image and title, and if either is wrong, correct the page's metadata and run the check again until the preview matches what you intend to publish.
That order is deliberate: rendering the card first reveals whether the page needs work before you polish any copy, and composing inside the preview catches character overruns a separate notes app would hide until posting time.
At a glance: paste, render, compose, fix, re-check.
Once the preview passes, the tweet is ready for your posting workflow. If you queue content ahead of time, the X Post Planner lets you schedule the post you just validated instead of publishing it on the spot.
What to Fix When the Preview Comes Back Wrong
A broken preview is a metadata problem, not an X problem. Cards are generated from Open Graph and Twitter Card tags in your page's HTML.
The Cards markup reference lists the exact tags the platform reads. One of those tags decides whether your link earns a small summary card or a full-width image card.
The fix always lives on the page, never in the tweet.
Image failures are the most common case. A cropped or missing picture usually means the file behind your image tag does not fit the card format.
Swap in an image with the right dimensions; the social media image sizes cheat sheet keeps the current numbers for X next to every other platform.
Stale cards are the sneakier case. Update a title or an image and cached previews can keep serving the earlier version for a while, so a page that looks fixed in your CMS may still render outdated when shared.
Re-running the validator after each change confirms the current state instead of leaving you to guess.
When a Link Preview Check Pays Off
Some links deserve the check more than others. These are the moments where a quick preview earns the most:
- Before a campaign sends paid or organic traffic to a landing page.
- After you change a page's title or preview image.
- Ahead of announcing a new blog post or product page.
- Any time you want to see the complete tweet, text plus card, in one view.
The mistake I see most often is teams validating the homepage once and assuming every campaign page inherits the same metadata. Each URL serves its own tags, so each URL gets its own check.
The common thread is stakes. A throwaway reply can survive a gray link box; a launch announcement cannot, because the card is doing the selling before a single word of your copy is read.
One Check Before Every Link
The preview habit is cheap insurance. Broken cards stay invisible until they are public, and the validator makes them visible while they are still private, from the card image down to the last character of your text.
It also fits neatly into a scheduled workflow. Validate the link first, then hand the finished post to a Twitter scheduler so it goes out at the time you chose, wearing a card you already approved.
And when a page's card refuses to cooperate on a deadline, native media is the dependable fallback. The walkthrough on how to schedule a Tweet with photo, video, or GIF covers that route step by step.
The check costs you a minute; a broken card runs for as long as the tweet stays up.
→ Preview your next link before you tweet it
What People Ask
Can I preview how someone else's link will look on X?
Yes. Circleboom's validator renders a card preview for any public URL you paste, including pages you do not own, which helps when you are sharing a partner's landing page and want to know what card will ride along with your tweet.
Paste the URL, click CHECK PREVIEW, and read the result the same way you would for your own page.
Should I check a link again if its card was broken the last time I tweeted it?
Yes, always re-validate before re-sharing. The check reads the metadata your page serves right now, so it tells you whether the earlier problem is fixed and keeps you from repeating the same broken card in a second tweet.
){kind=link}
