Most bad posts are not bad ideas. They are a good caption with the wrong image, a link that turned into a grey box, or a sentence that gets cut off right before the point. All of that is visible before you publish, if you know where to look.
This is a checklist for that look. It assumes you already know the composer has a live preview. If you want the tour of the feature itself, start with per-platform captions; here the question is what to check, in what order, and what to do when something is off.
A worked example: one launch post, four networks
Say you are announcing a new guide. You have a blog URL, a 1200 x 630 image, and a caption of about 400 characters. You select LinkedIn, X, Instagram and Bluesky.
Step 1: write the caption once, then read the X preview first. X is the tightest of the four, so it fails first. The composer shows a warning naming the network, its limit and your current count. At 400 characters you are well over, and the composer offers to split the text into a thread. You decide you would rather keep X to one post, so you open the X tab and write a shorter version just for that network.
Step 2: check the link card, with no image attached. You paste the blog URL. About half a second after you stop typing, the preview reads the page and draws a card under the caption on LinkedIn, X and Bluesky. Instagram shows no card, and that is correct: a link in an Instagram caption is plain text. So you decide the Instagram version needs “link in bio” wording instead of the URL.
Step 3: attach the image and watch the cards disappear. The moment you attach your 1200 x 630 image, the cards are replaced by the image on every network. This is the decision that matters most in the whole workflow. Either you want a clickable card (post without media) or you want your own image (keep it, and accept the link is just text or a small attachment). You cannot have both in the mockups.
Step 4: look at the crop. The Instagram preview frames your image for its feed. A wide banner that looked fine in the editor now has its headline cut at the edges. You swap in a square version for Instagram only and leave the wide one on the other three.
Step 5: read it as a stranger. Scroll through each mockup as if you had never seen the post. Does the first line make sense without the rest? Does the image say the same thing as the words? If you would scroll past it, so will everyone else.
Total time: a couple of minutes. What it caught: an over-limit caption, an Instagram link that would have been dead text, and a banner with a clipped headline.
The checklist
Run through these for every post that matters. The first four are mechanical, the rest are judgement.
- Counter and warnings. Any red warning above the preview or beside a channel needs fixing before you can submit. Treat the counter, not the mockup’s own shortening of a long caption, as the truth about length. The numbers per network are in social media character limits.
- Media against post type. If you chose a type that needs a video and attached an image, or the media count does not fit the type, the warning starts with the network’s name. Fix it here, not after a failed publish.
- Link card present or intentionally absent. If you expected a card and there is none, see the troubleshooting list below.
- First link is the one you want. The card is built from the first link in the caption only.
- Image crop on every network. Check faces, text overlays and logos near the edges. Sizes by network are in social media image sizes.
- First line. On feeds that fold long captions, the opening is what people see before deciding whether to tap. Put the point there.
- Per-network wording. If one caption reads well on LinkedIn and badly on X, give X its own version instead of squeezing.
- Thread order. For threads, check the connected view. Each part should make sense if someone lands on it from a quote.
- Call-to-action button (Google Business Profile). That network shows a button rather than a link card, so check the button label and destination, not the caption.
Common mistakes
- Previewing before attaching media, then not looking again. Attaching an image changes the layout and removes the link card. Always look after the last change.
- Trusting the card forever. The preview reads your page as it is right now. If you fix a title or swap the share image after a network has seen the link, the network may keep showing the old version for a while. Fix the page first, then post.
- Several links, one card. Only the first link is carded. A second link further down is plain text.
- Previewing one network and assuming the rest. The X tab can look perfect while the Instagram crop is wrong. Click through every tab.
- Treating a mockup as a screenshot. Fonts, spacing and button styles are close, not exact, and networks change their designs without notice.
Why isn’t my link card showing?
Work down the list in order.
- The network does not show cards. Cards appear in the previews for Facebook, X, Threads, Bluesky, LinkedIn, Mastodon, Discord, Telegram and Tumblr. Instagram, YouTube, TikTok, Pinterest, Snapchat and Google Business Profile never will.
- Media is attached. Remove it to see the card.
- The page has no share tags. The card uses the page’s own share title, description and image, falling back to its page title and description. A page with none of these gives a sparse card or none.
- LinkedIn needs a title. The preview only draws a LinkedIn card when the page has a title. Without one, the link publishes as a plain link.
- It is not the first link. Move it to the front.
- The page is slow, behind a login, not HTML, or on a private address. The check gives up after a few seconds and only reads the start of the page. Private and local addresses are refused, so a staging site on your own network will not unfurl.
A failed fetch never blocks publishing. It just means no card in the preview.
Links to well-known video and audio sites are handled separately: the title, channel and thumbnail come from the site’s own embed information, because the pages themselves return nothing useful.
What only the network decides
A preview is our drawing of a network, not the network. A few things stay out of your hands:
- The network may build its own link card at a different moment, from an older copy of your page.
- Crops can be reframed differently from the mockup.
- Feed ranking, “see more” folds, translations and each viewer’s own settings.
So publish the important posts and give them one last look on the live channel. If a client has to approve first, a review link shows them the post without an account; the process is in getting client feedback on social media posts and the feature is client review links. If the caption is the weak spot rather than the layout, the AI caption assistant can draft or tighten it from the same composer.
Plans
Previews are part of the composer, with no separate allowance. The limits that apply are the ones on your plan.
BulkPublish supports 15 platforms: Facebook, Instagram, TikTok, YouTube, X, Threads, Bluesky, Pinterest, Google Business Profile, LinkedIn, Mastodon, Discord, Telegram, Tumblr and Snapchat.
- Channels: Free: 3 (1 per platform). Pro: 30 (2 per platform). Business: 75 (5 per platform).
- Posts: Free: 3/day. Pro: 30/day. Business: unlimited.
You can try the composer and its previews on the free plan: start free at BulkPublish.