LinkedIn post preview: test mobile and desktop feeds

A LinkedIn post preview tool is a check of the first screen, on the client a reader actually uses. Most readers open LinkedIn on a phone. The desktop feed is a wider column of the same post. Those two screens do not show the same number of words before "see more," and LinkedIn does not publish the cut. A counter that stamps 210 characters on every draft is not a preview. A screenshot of your own composer, with the lines still expanded because you are the author, is not a preview either.

Boykli writes the draft and can publish it to the personal profile you connect. It does not draw a mobile feed or a desktop feed, and it does not place a "see more" marker in the editor. Create posts returns plain text. The carousel page previews the slides you are designing. The article and YouTube modes can show the image you chose to attach. None of those surfaces is the LinkedIn column. If the job you are paying for is a replica of the feed, with bold, a fold, and light and dark, that product is a different one. The comparison is AuthoredUp alternative. This page is the test you run on the draft after it exists.

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What you are actually testing

The feed clamps the commentary, then offers "see more." People who have measured it, including AuthoredUp, put the opening near 210 characters on desktop and near 140 on mobile. Other write-ups describe the same behavior as about three lines, not as a character rule. Both descriptions can be true at once. A wide column fits more characters into three lines. A phone fits fewer. A blank line spends a whole line on nothing, so the character count inside the clamp collapses. Treat 140 and 210 as someone else's measurement. They are not a LinkedIn specification, and they move when the client, the font size, or the line breaks change.

LinkedIn does document a ceiling. A post can hold up to 3,000 characters, and a longer piece belongs in an article. That ceiling includes spaces and line breaks. It is the wrong number for a preview. A 2,400-character post and a 400-character post can show the same opening if the first lines match. The rest is behind the tap. How the public 2026 datasets split character bands from line counts, and which of them compare a writer with themselves, is Best LinkedIn post length.

The preview also includes whatever is not text:

• A link can become a card. The card has its own title, domain, and image. The fold of the commentary is a separate problem from whether that card is the one you wanted.
• An image sits under the commentary. The clamp still applies to the words above it.
• A document post shows a thumbnail of the file, usually the first page, plus the commentary. The slide you designed and the card the feed shows are different rectangles.
• A very tall attachment uses the phone screen. Readers may never reach a caption that you placed after the media, or a "see more" that sits under a large card.

A preview that only counts characters misses every row except the first.

Four ways people "preview," and what each one can see

The native composer is the ground truth for the account you are about to use, and it is a poor preview while you are still typing. Your own draft stays expanded. The clamp is what other people get in the feed. A two-column tool is useful because it forces the narrow width before you publish. It is still a simulation. Large text in the phone's accessibility settings, a different app version, or a card LinkedIn lays out differently will move the cut. A character-count page is a reminder, not a test. Boykli is the writing step in front of whichever of those checks you choose.

The same draft, on a phone and on a desktop

This opening is 91 characters, including the period:

We cut webhook retries from 11 to 2 by rejecting the duplicate event id before the handler.

On a phone, a line holds roughly the mid-40s of characters once padding and a normal font are in play, so this sentence wraps to about two lines. On a desktop column it is often one line, sometimes two. It fits inside both of the commonly cited clamps, as long as nothing is sitting above it and there is no blank line inside it. The point is in the sentence. A reader who never taps "see more" still learns the number and the method.

Now spend the clamp on purpose, with the same fact broken into three short lines:

We cut retries.

From 11 to 2.

Here is how.

The character count is tiny. The line count is three. If the feed is clamping lines, "see more" lands on "Here is how." and the method never appears. A preview tool that only checks "under 140 characters" marks this draft as safe. A phone marks it as empty.

Put the 91-character sentence back, then a blank line, then the evidence. The blank line is part of the opening block. On a three-line clamp, the phone may show the sentence, the gap, and nothing else. Desktop, with more characters per line, may still show the first sentence of the next paragraph. That is the whole mobile-versus-desktop gap for text posts. It is not a different algorithm. It is a narrower column.

Large text on the phone is a second test, not a niche one. The line clamp does not grow when the letters do. A sentence that fit on two lines at the default size can fall onto three, and the last words disappear behind "see more." If you only check a desktop monitor, you will not see it.

A test you can run on one draft

Do this before the queue sends the post. Fixing the live post after the first distribution is a different, worse test. People already saw the opening you did not check.

1. Finish the words in Create posts. Short is labeled 45–400 characters, medium 400–1400, long 1400–3000. Those labels are the writing target. The LinkedIn ceiling on the way out is still 3,000. YouTube, article, series, and document modes start from a source. The draft comes back as plain text, with the line breaks the model wrote and no feed frame around them.
2. Read the first line as the entire post. If the verb, the number, or the decision is missing, rewrite the line. Alternate openings, when you turn that switch on, replace the first line and leave the body. That behavior is the hook generator. A preview will not rescue a line that is only a topic.
3. Count lines in the opening, not only characters. One sentence. No blank line inside it. No hashtag row above it. No "1/7" and no emoji prefix. Then one blank line, then the evidence. How those breaks should look, and which invisible characters ruin them, is LinkedIn text formatter.
4. Open the same text in two widths before you publish. Paste it into a preview tool that draws a desktop column and a phone column, or paste it into LinkedIn's web composer and into the LinkedIn app without posting. Look at the first screen on each. Ignore a green badge that says the draft is "under 210." Confirm the sentence you care about is still visible on the phone, at the font size you actually use, and again with the phone's larger text if you can turn that on for ten seconds.
5. Check the attachment as its own object. If you attached an article image or a YouTube thumbnail in Boykli, that file is what will go out with the post. Look at it on a phone: a wide thumbnail crops differently than it does in the dashboard. If the post is a document, preview the slides on the carousel page. The on-screen preview and the PDF share a canvas. The feed then shows the first page as a card, not the full deck. Square and portrait sizes, and the type that survives a small card, are LinkedIn carousel dimensions.
6. If a URL must stay in the commentary, look at the card LinkedIn builds, on both clients. Title, image, and domain come from the page, not from your draft. A preview tool that does not fetch the link will show the raw URL and call the test finished. It is not finished.
7. Style nothing until the plain version passes the phone. If you still want one bold label, do that after, on a span that is not the hook, and look at the phone again. Some phones drop uncommon glyphs. A label that looks sharp on a desktop font and empty on a phone has failed the preview. The code points, and the italic h that many formatters miss, are on the formatting page.
8. Put the text you just approved back into the Boykli draft if Boykli is going to publish it. The queue sends the copy it has stored. A fixed version that lives only in a preview tab will not go out. Publish strips the internal === CTA === marker and sends the commentary. Scheduling for the personal profile is LinkedIn scheduling tool. Company pages are not a destination from Boykli. The feed clamp on a page is still a client behavior, and you would check it in the tool that actually posts as the page.

Two refinements exist on a draft. Use them to move a fact into the first line or to remove a blank line. Do not use them to ask for a mobile mock. Managed accounts include 130 post refinements a month, inside a cap of 210 posts. BYOK has no Boykli generation cap. You still pay OpenRouter for chat and images, and Google AI Studio for Voice Agent.

What a passing preview looks like

A passing text post, on both clients:

• The first line is one sentence a stranger can understand with no second line.
• That sentence is still fully visible on a phone at default size, and it does not end mid-word when text size is bumped.
• The next paragraph starts after a single blank line, not before the first sentence has a verb.
• Lists, if any, start after the fold. A bullet list of teasers is not an opening.
• Links, mentions, and any hashtag you added yourself are plain characters. A styled letter inside a URL is a broken URL, and it also changes how the line wraps.
• The attached image or the document's first page is recognizable at the width of a phone, without relying on a caption that sits under "see more."

A failing preview is usually one of four drafts. The opening is a label ("A lesson from this week") and the point is on line four. The opening is three stacked fragments. The opening is fine on desktop and clipped on the phone because a bold word wrapped earlier than the plain word did. Or the text is fine and the card is wrong: the link unfurled an old image, or the PDF's first page is a title in type that becomes a smudge at feed size.

Run the phone check last, after the words are done. Running it on an outline wastes the test. Skipping it because a desktop screenshot looked finished is how the phone feed ends up with half a sentence.

FAQ

Does Boykli include a LinkedIn post preview for mobile and desktop?

No. Create posts is a text draft. The carousel page previews slides. Article and YouTube modes can show the image you are attaching. None of those is a LinkedIn feed, in light or dark, with "see more" on a phone column and a desktop column. Paste the finished draft into LinkedIn on both clients, or into a tool that draws both columns. Then save that exact text back to Boykli if the queue is what will publish it.

How many characters show before "see more"?

LinkedIn does not publish that number. Measurements repeated across preview tools put the opening near 210 characters on desktop and near 140 on mobile, and several guides describe a clamp of about three lines. A blank line, a hashtag row, or a larger phone font moves the cut. Test the lines. Do not treat 140 as a rule LinkedIn promised.

Is the desktop preview enough if I write short lines?

No. Short lines are the case where desktop and mobile disagree the most, because each line costs the same in the clamp and holds fewer words on the phone. One long sentence that states the point is safer than three short lines that tease it. Confirm that sentence on a phone, not only in a wide browser.

Will a preview tool match the live feed exactly?

It will match the draft you pasted, at the width the tool chose. It will not match a later font change, a link card it did not fetch, or a document thumbnail LinkedIn crops on its own. Use the tool to catch a broken opening. Use the LinkedIn app and the desktop site before you publish anything you cannot stand to have people see for the first hour.

Does the 3,000-character limit matter for the preview?

Only as a ceiling. The preview is the opening lines. Long mode in Boykli is labeled up to 3,000 because that is the LinkedIn post cap, not because readers see 3,000 characters. Spaces and line breaks count. Styled letters sit outside the Basic Multilingual Plane, so a counter that uses UTF-16 can charge two units for one mathematical letter. Leave a margin if you style anything. The mapping is on LinkedIn text formatting.

Can I preview a carousel caption and the slides together?

You can preview the slides in Boykli, at the canvas they will be printed to PDF. You preview the caption the same way you preview any other post: first line, phone width, then desktop width. The feed shows the caption clamp and a card of the first page. A beautiful slide two does not repair a caption that never states the point. Company-page document posts are outside Boykli. The personal profile is the account the queue can reach.

Do I need a paid seat to run this test?

You need a paid seat to have Boykli write, attach an image, build the carousel, publish, or schedule. BYOK is $29 a month. Managed is $88 a month. Looking at a draft you already wrote, in LinkedIn's own composer, does not require Boykli. Browsing Radar and Algorithm does not either. The test on this page is the step between a finished draft and a post other people will see.