Why Do Character Limits Matter?
Every ad platform limits the length of the text that can be written into its fields according to its own interface design. Text that goes over that limit is either rejected outright by the ad platform or shown to the user in truncated form. Making sure headlines and descriptions stay within the relevant platform's limits before a campaign goes live both avoids the risk of rejection and keeps your message from appearing incomplete.
Google Ads Character Limits
In Google Ads the headline field accepts a maximum of 30 characters, and the description field a maximum of 90 characters. These limits are hard technical ceilings; text that exceeds them is not accepted in the ad interface.
Google Ads' Responsive Search Ads feature lets you submit up to 15 headline and 4 description variations in a single ad; Google's algorithm then mixes those variations automatically and tests them in different combinations. This approach requires every headline and description to be written individually within its own character limit; a single variation that exceeds the limit causes that variation to be rejected.
Meta (Facebook/Instagram) Ads Limits
In Meta ads the headline field is limited to 40 characters. The recommended length for the primary text is 125 characters; that one, however, is not a hard technical ceiling. You can write more, but Meta cuts the text at that point and shows a "See more" link. Since a large share of users never click that link, failing to fit the most important part of your message into the first 125 characters can weaken the ad's impact.
X (Twitter) and LinkedIn Limits
On X (formerly Twitter) a standard post is limited to 280 characters; this is a hard technical limit, and text beyond it cannot be posted. In LinkedIn ads the recommended length for the introductory text is 150 characters; much like Meta's primary text, the platform shortens the text beyond that length and shows a "...see more" link. The LinkedIn headline field is limited to 70 characters.
| Platform / Field | Character Limit | Type |
|---|---|---|
| Google Ads — Headline | 30 | Hard limit |
| Google Ads — Description | 90 | Hard limit |
| Meta Ads — Primary Text | 125 | Recommended (before truncation) |
| Meta Ads — Headline | 40 | Hard limit |
| X (Twitter) — Post | 280 | Hard limit |
| LinkedIn — Introductory Text | 150 | Recommended (before truncation) |
| LinkedIn — Headline | 70 | Hard limit |
Why Must Every Google Ads Headline Stand on Its Own?
In Responsive Search Ads, once you have submitted 15 headlines and 4 descriptions, Google's algorithm decides which headline appears with which description and in what order. That means every headline has to deliver a meaningful, complete message when read on its own, independently of the others. Phrases such as "...and more" that give the impression of continuing a previous headline can end up meaningless when they turn up in a different combination.
Practical Tips for Writing Ad Copy
- Put the most important offer or call to action at the start of the text; critical information should never be left to the end in fields that risk being truncated.
- Rather than copying the same core message from platform to platform word for word, rewrite it for each field's character limit; a compressed sentence usually loses its natural ring.
- Build Google Ads headlines so that each one is independent and makes sense read on its own.
- Check the copy in the relevant platform's preview feature before going live; the character counter shows where you stand relative to the limit but may not always reflect the visual truncation point exactly.
- If the campaign spans several platforms, simplifying the message to fit the tightest limit (such as the Google Ads headline) and then expanding it on the other platforms gives you a more controlled process.
The Difference Between a "Hard Limit" and a "Recommended Length"
Telling these two concepts apart is critical when writing ad copy. A hard limit is a boundary that cannot technically be crossed; the field simply does not accept more than that number of characters. A recommended length expresses the number of characters the platform will display before it truncates the text; you can technically write more, but the truncated part hides behind a link. It is always safer to place an ad's most important offer or call to action inside the recommended length, in the part that carries no risk of being cut off.
What the Different Formats Have in Common: A Clear Message in a Confined Space
Google Ads, Meta, X and LinkedIn are independent products, but they all share one design logic: showing short, scannable text without disrupting the user's flow (a feed, a list of search results). That is why character limits diverge as the number of platforms grows, while the goal stays the same: keeping your message plain enough for the reader to grasp in a few seconds.
When you run the same campaign across several platforms, trying to shorten one long piece of copy is less effective than first clarifying the product's or service's core value proposition in a single sentence, then reshaping that sentence for each platform's limit. This approach also prevents the brand from sending disconnected messages on different platforms.
Check It With the KEYDAL Ad Character Counter
Counting every field by hand while adapting the same ad copy to several platforms wastes time and increases the risk of error. The KEYDAL Ad Character Counter brings all the ad fields of Google Ads, Meta, X and LinkedIn together on one screen, and shows you live, as you type, where each field stands relative to its limit.
Checking every field this way before a campaign goes live greatly reduces the risk of rejection or a truncated message, and saves time when adapting a single piece of copy from platform to platform. As you write, the moment the counter turns from green to red you can see exactly which character crossed the limit — which makes it easier to build the copy at the right length from the start rather than trimming it per platform afterwards.