Two kinds of limit, and only one of them tells you
Every character counter treats a limit as a limit. There are two, they fail completely differently, and the difference is where money goes.
A hard limit rejects the ad. Google's headline is 30 characters and the field will not take a 31st. You find out immediately, you shorten it, nothing is lost. This is the benign one.
A truncation point does nothing at all. Meta will accept two thousand characters of primary text. It will run the ad. And on a phone it collapses behind a "See more" after roughly 125 characters, which almost nobody taps.
Nothing is rejected. Nothing warns you. It looks perfect in the editor. Your call to action is written, paid for and invisible, potentially for months.
Which is why this page shows you the cut
When a field goes past its truncation point, the tool prints what a reader would actually see, ending where the platform ends it. That is a more useful thing to look at than a number going red, because it shows you which half of your sentence survived.
The fix is almost always the same and almost always feels wrong: put the important thing first. Copy that builds to its point is good writing and bad advertising, because the build gets cut.
Google assembles your headlines without asking
A responsive search ad takes up to fifteen headlines and four descriptions, and combines them in orders you do not control.
So a headline that only makes sense after the one before it will, sooner or later, run without it. "And half the price" is a fine second line and a baffling first one.
Every headline has to be a complete thought that reads correctly next to any other. That constraint is annoying and it is also why responsive ads work: fifteen self-contained claims beat one carefully built paragraph, because the platform can find the combination that suits each search.
Double width languages count double
Google states it plainly: every character in a double width language such as Korean, Japanese or Chinese counts as two against the limit. A 30 character headline is fifteen characters of text.
There is a switch for it, and it is off by default because most people reading this will not need it. It is cheap to get right and expensive to discover.
These numbers move and nobody tells you
Ad platforms change specifications without an announcement, without a changelog, and often without consistency between their own help pages.
So every figure here carries the date it was checked and the source it came from, on the tool itself rather than buried in a footer. The Google limits were read from Google's own help page. The others carry their date the same way.
If a platform rejects an ad at a length this page says is fine, the platform is right and this page is out of date. That is the honest instruction, and a tool that implies otherwise is selling you a certainty it does not have.
Common questions
What are the Google responsive search ad limits?
Up to 15 headlines at 30 characters each, up to 4 descriptions at 90 characters each, and two display path fields at 15 characters each. Those are hard limits: the field will not accept more, so you find out immediately rather than later.
What is the difference between a hard limit and a truncation point?
A hard limit rejects the ad. You find out at once and you fix it. A truncation point does nothing at all: the platform accepts your text, runs the ad, and simply stops showing it after a certain length. Nothing warns you, it looks correct in the editor, and the end of your sentence is written, paid for and invisible. The second one is the expensive problem and almost no character counter separates them.
How long should Meta primary text be?
The first 125 characters or so are the whole ad on a phone, because everything after that sits behind a "See more" that very few people tap. There is no meaningful hard limit, so you can write two thousand characters and nothing will stop you. If your copy builds to its point, the point is behind the fold. Put the offer or the question first and the context after it.
Why does each Google headline need to work on its own?
Because a responsive search ad assembles them in combinations you do not choose. Write a headline that only makes sense after the one before it and it will eventually run without it. Every headline has to be a complete thought that reads correctly next to any other.
Do emoji and accented characters count as one?
Yes, one each, and this page counts characters rather than bytes so it agrees. The exception is double width languages: Google states that every character in Korean, Japanese or Chinese counts as two, so a 30 character headline is 15 characters of text. There is a switch for that.
Are these numbers permanent?
No. Platforms change limits without an announcement and without a changelog. Every figure here carries the date it was checked and the source it came from. If a platform is rejecting an ad at a length this page says is fine, believe the platform.