Meta's character limits are the most boring part of Facebook advertising, and they've killed more of my ad drafts than any algorithm change ever has.
You write something sharp. You paste it in. The preview chews it off at "See more" and the punchline never loads. Or the headline gets sliced on mobile and reads like a ransom note.
So let's talk about the real numbers, what a facebook ad copy tool should actually be doing with them, and how to write headlines and primary text that survive contact with the ad preview.
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Use the tool free →The Meta character limits, in plain numbers
Here's what you're working with inside Ads Manager.
Primary text
- Recommended: about 125 characters before the "See more" cutoff
- Hard cap: 2,200 characters
That 125 number gets argued about constantly. Meta's own guidance says keep the message to roughly 125 characters so the whole thing shows. In practice, the truncation point moves around depending on placement, device, and how the preview feels that day. What doesn't move: whatever sits in the first 125 characters is your ad. Everything after is a bonus most people never read.
Headline
- Recommended: 27 characters
- Hard cap: 40
27 characters is brutal. That's "Free shipping today" and change. It's also why so many headlines read like they were written by a robot that resents you.
Link description
- Recommended: 27 characters
- Hard cap: 30
It barely shows on mobile. Treat it as optional and don't lose sleep over it.
The gotcha nobody warns you about
Emojis and special characters don't always count as one. Some get counted as two. So your carefully measured 125 can quietly be 130, and the last word — usually the one carrying the whole hook — gets cut. If your tool doesn't count the way Meta counts, it's lying to you.
What a Facebook ad copy tool should actually do
Most "AI ad writers" do one thing: generate text. That's the easy part. Any model can spit out 40 variations of "Shop now, 50% off."
The hard part is everything around the text.
Count characters the way Meta counts them
Per placement. Facebook feed, Instagram feed, Stories, Reels, Audience Network — different display spaces, different squeeze. A headline that fits the feed can get sliced in Reels. A tool showing you one counter for one field isn't helping.
Generate to the limit, not past it
I want a tool that says "here are 8 headlines, all under 27 characters." Not one that generates 60 characters and leaves me doing Word Surgery at 11pm.
Give me variants that differ in angle, not in adjective
Ten versions of "Premium quality" is one ad, not ten. I want a benefit angle, a price angle, a problem angle, a proof angle, an objection-handling angle. That's what makes testing worth the spend.
Handle the primary text/headline relationship
These aren't two separate pieces of copy. The headline is the second hook. If the primary text already said "free shipping," a headline repeating it burns the only other real estate you've got.
Keep brand voice out of the gutter
Generic AI copy has a smell. You know it the second you read it. A decent tool lets you feed it constraints — tone, banned words, actual offer details — so you're not rewriting every single line by hand.
The split that decides whether your ad works
Here's how I think about it: primary text does the persuading, the headline does the closing.
Primary text has room to build a case — problem, agitation, solution, proof, offer. But only the first line or two is guaranteed to be seen. So the structure I'd use:
- Line one: the interrupt. A specific claim, a question, a mild callout.
- Line two: the context that makes line one believable.
- After the fold: the details, the offer, the CTA.
The headline has no room for any of that. It's got one job: give a reason to click now. Not "Learn more about our range." More like "Ends tonight — 40% off."
Saying that out loud makes it sound obvious. Then you open an ad account and see 14 headlines that all say "Shop Our New Collection." Ever done that? I have. More than once.
If you want a fast gut check on whether your headline is doing anything at all, run it through the Free Headline Generator and compare its outputs to yours. Not to copy them — just to see how many angles you left on the table.
A workflow that fixes truncation before it happens
The mistake is writing copy and then fitting it. Fit first, write second.
Step 1: Pick your placement mix
Decide now whether you're running feed only or feed plus Reels plus Stories. That changes your effective limits. Write for the tightest placement you're buying.
Step 2: Generate to spec, not to vibes
Feed the tool the constraints up front: headline ≤ 27 characters, primary text lead ≤ 125, one offer, one audience. If the tool can't take constraints, generate 30 options and cut 25 yourself.
This is where something like AdCreator AI earns its keep — it generates copy and creative together, so the headline you write is the headline that appears on the image, not a different one hiding in a spreadsheet. Reviewing one coherent set beats stitching two together.
Step 3: Grade before you spend
Before anything goes live, check the pairing. Does the headline add something the primary text didn't already say? Does the first 125 characters work as a standalone? The Free Ad Grader is a quick way to pressure-test that without dragging a colleague into it.
Step 4: Make the variants genuinely different
Five angles minimum. Benefit, price, problem, proof, objection. If two variants could be swapped without anyone noticing, delete one.
Step 5: Write the second line last
Sounds backwards. It isn't. You don't know what the first line needs to support until the first line exists.
Where AI ad copy still falls flat
Honest assessment, since I use these things daily.
It's bad at specifics it doesn't have. If you never tell it that shipping is free over $50 and returns run 30 days, it'll invent something plausible and wrong. Feeding it real offer details is on you.
It's bad at restraint. Ask for a headline and you'll get adjectives stacked on adjectives. "Premium quality organic cotton" is 31 characters and says nothing useful.
It defaults to the same twelve words. Elevate. Discover. Unlock. Game-changer. Revolutionary. Once you see it, you can't unsee it. Ban them in your prompt.
And it doesn't know your customer. The best headlines I've come across trace back to a real complaint in a review section, or a phrase a customer actually used. AI can polish that. It can't find it.
So my take: use the tool for volume and constraints, keep your own judgment for angle and hook. The Ad Gallery is worth a browse for this — it's real AI-generated ad output, so you can see what the good and bad versions look like side by side before you commit budget.
If you're comparing tools anyway, I wrote up how to pick a Facebook ad copy tool that writes ads you can actually run, and the AI ad generator breakdown for Facebook covers where most of them fall over.
One more thing, if you're on Shopify: the copy problem compounds because you're matching product pages and offers too. How to write Shopify ad copy that sells goes deeper on that specific mess.
The limits are a writing constraint, not an admin annoyance
27 characters isn't a technicality. It's a forcing function. If you can't say why someone should click in 27 characters, you probably don't know why they should click.
Same with 125. If your hook needs 200 characters to land, the hook is weak — not the limit.
Treat the limits as the brief. Write to them from the start, generate in bulk inside them, and check the pairing before you spend a cent.
Then check your captions, because Instagram truncates differently again — the Free Instagram Caption Generator handles that side if you're cross-posting.
FAQ
How many characters can Facebook ad primary text be?
The hard cap is 2,200 characters, but only about the first 125 show before "See more." Put the hook and the offer inside that first 125 and treat everything after it as supporting detail for the minority who tap through.
What's the ideal Facebook ad headline length?
Meta recommends 27 characters, with a hard cap of 40. But short isn't the goal — specific is. "Sale" is short and useless. Aim for a real, concrete reason to click inside 27 characters.
Can an AI tool write Facebook ad copy that fits Meta's limits?
Yes, if it generates to constraints rather than generating freely and leaving you to trim. Ask for headlines under 27 characters and a 125-character lead, then re-check the count in Ads Manager — emojis and some special characters count as more than one.
Do Facebook ads still have a 20% text rule?
No. Meta retired the 20% text-on-image limit and now factors text volume into delivery instead of rejecting the ad outright. Copy limits still bite, but through truncation rather than disapproval.