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When Right Is Also Wrong

Every ad text field has two limits — the one that stops your ad running, and the one that decides how much of it anyone sees — and almost every guide quotes the first while the second is the one doing the damage.

An ad can sit well inside the character limit printed in the specification and still lose half its words before anyone reads them, because the number that rejects an ad and the number where the platform stops showing it are two different numbers, and they can be a long way apart. Nothing breaks when you cross the second one: the ad publishes, the budget spends on schedule, and the sentence meant to do the work sits behind a "See more" that most people never tap.

That is what makes it difficult to catch, because there is nothing to catch — the platform accepts every character exactly as documented and reports no problem at all, having decided separately, and without telling you, how many of those characters it intends to put on a screen.

Being within the limit and being read are two different questions, and the number everyone checks only answers the first one.

The two numbers

Every text field in an ad platform has two thresholds, and they can be wildly far apart.

• The hard limit. Go past this and the platform refuses your ad, so it fails, you get an error and you fix it before anything runs — annoying at the time, but it tells you the truth immediately.
• The truncation point. Go past this and the platform accepts your ad and shows less than you wrote, leaving the rest behind a "See more" that few people tap. This is the expensive one, because the ad runs and the budget spends while the part you were relying on goes unread.

When someone says "the LinkedIn character limit is 3,000", they are quoting the hard limit, which is true and very nearly useless, because LinkedIn shows about 150.

That twentyfold gap is a large space in which an ad publishes perfectly, passes every check available to you, and is broken in the only way that matters.

The cut lands mid-word, in the middle of "can't". Everything after the fade is still there — it's just behind a tap most people never make.

Facebook and Instagram: there is no hard limit

Meta works differently again, in a way that catches out the people who are being careful rather than the people who aren't.

For an ordinary single-image link ad, Meta does not publish a maximum character count at all. Not for the primary text, not for the headline, not for the description. Every field in the Marketing API reference is typed as a plain string with no stated ceiling. The only hard cap documented anywhere near this is Instagram's 2,200-character caption — and past that the ad doesn't get trimmed, it fails to deliver on Instagram entirely.

So the famous "125 characters" everyone repeats is not a limit at all but a truncation guide, the point at which Meta stops showing your words. If you treat it as a hard limit you will trim ads that never needed trimming, and if you ignore it you will buy impressions for text nobody sees.

Meta says as much in its own help centre: text may be truncated if it exceeds the character limitation, and "your text may be further truncated across various placements and devices". That second clause carries most of the weight, because it is where the number stops being a single figure.

The number depends on where the ad runs — and it varies a lot

"125 characters" is a cross-placement average. The real figure depends entirely on which surface someone is scrolling when your ad appears, and the spread is much wider than most people expect.

Meta's own recommended lengths, per placement, for a single-image ad. Characters, approximate — Meta states them as guidance, not guarantees.

Forty-four characters is hard to picture until you watch it happen to a real sentence, so here is the same opening again, cut where Reels cuts it.

It doesn't stop at a word, a comma or an idea. It stops at character 44, mid-word, in the middle of "websites".

What turns this from trivia into money is Meta's default placement setting, Advantage+ / automatic, which runs your ad across every one of those surfaces. Unless you went in and restricted placements deliberately, your ad is running in Reels, so for most advertisers most of the time the binding number is not 125 but 44, and the whole ad has to survive on its opening clause.

The part most guides won't tell you: sometimes the right number is unusable

We could stop there, hand you the smallest figure in the table and tell you to write to it, which is what a good deal of advice does and what we think is a mistake.

Look at the headline column, where Facebook Reels shows about ten characters — roughly "Handmade b". There is no headline anyone can write to that length that does any work at all, and advice that tells you to try has stopped being useful without stopping being confident.

So the honest reading splits in two:

• Write to the feeds. Facebook Feed and Instagram Feed are where the words are the ad, which means 125 to 150 characters of primary text and a headline under about 27, and those are targets you can actually hit.
• Know what happens in the video placements. Reels and Stories are not text surfaces, and your copy is an overlay on someone's full-screen scroll, so what wins there is the image or the first four words rather than a sentence. Treat the 44 as a fact about that surface rather than a brief to write to.

An instruction nobody can follow doesn't just fail — it teaches the reader to ignore the next one too.

What to actually do about it

The fix is almost never "write less". Long copy earns its place, because the people who tap "See more" are the interested ones and giving them somewhere to go is the point of writing it. What matters is that the part before the cut can stand on its own.

• Front-load the whole proposition. The first sentence has to say who you're for and what you do, without a warm-up or a scene-setting clause in front of it, because for a large share of your audience it is the only sentence there is.
• Don't split a thought across the cut. The worst outcome isn't losing the second half, it's a first half that reads as incomplete and gives someone a reason to scroll on.
• Put the brand name early. If it lands after the cut on the tightest placement, a chunk of your spend bought an anonymous ad.
• Check the headline separately. Twenty-seven characters is tight, and headlines are where people overrun without noticing, because the box you type into is wider than the feed the headline lands in.
• Read your own ad at the cut. Paste the first 125 characters somewhere on their own and see whether they would make you stop scrolling — it takes half a minute and it tends to change what you write next.

And one rule that isn't a rule any more

While we're here: if anyone tells you that no more than 20% of your ad image may be text, they're working from a rulebook that was retired years ago.

The rule went, and so did the tool that measured it, and the help article once titled "About Text in Ad Images" is now about safe zones and doesn't mention 20% anywhere. A remarkable amount of ad advice still states it as law, because it was repeated so widely for so long that it outlived the thing it described.

That is worth remembering about this whole category of advice, because ad specifications change without announcements and often in ways that invalidate the confident listicle you happen to be reading. Meta changed its recommended feed image from square to 4:5 (1440 × 1800) not long ago, and plenty of guides still tell you 1080 × 1080 is what you want.

Advice about a moving target needs a date on it. Anything that doesn't tell you when it was last checked is asking you to trust it forever.

Where this leaves you

Most ads are within their limits and most ads are also cut well short of their last word, and the gap between those two facts is where a good deal of small advertising budgets go. When we ran this check across the ten most recent ads written in Fly Away Paul, every one of them was over the cut, with bodies running from 179 to 666 characters against a window of 125 to 150.

That isn't a skill problem so much as a reporting one, because the platforms publish one number prominently and enforce a different one invisibly, and nothing in the place where you actually write the ad tells you which of the two you are up against.

Related reading

If you're weighing up where your effort should go before you spend anything on ads, why your marketing needs a system covers the sequencing. And if the writing itself is the sticking point, how to make AI write in your brand voice is about getting copy that sounds like you rather than like everyone else — which matters twice as much when only the first line survives.