Em dashes in website copy: why they read as generated, and what to use
An em dash now and then is fine. One in every other sentence makes copy feel breathless and, to many readers today, machine-written, because AI models lean on the mark heavily. Most em dashes in website copy can become a full stop, a colon, a comma or a pair of brackets, and the sentence usually gets clearer in the process.
A useful mark that got overused
The em dash is an old printer's mark, named for being about the width of a capital M. Writers have always used it for an interruption, an aside or a sudden turn, and some house styles use it freely. Nothing about it is wrong. The problem is frequency. Language models reach for it constantly, to join clauses, add asides and build a pause before a punchline, and as generated copy spread across the web, readers learned the pattern. A landing page with a dash in the headline, two in the intro and one in every feature card now reads like a first draft nobody edited.
There's a practical cost too. Dashes let a writer avoid deciding how two ideas relate. A colon says "here's what I mean"; a full stop says "new thought"; a comma says "this belongs to the sentence". A dash says only "something follows", so a paragraph full of them is vaguer than it looks.
Em dash vs comma, colon and full stop
| The dash was… | Use instead | Example |
|---|---|---|
| Introducing an explanation or list | A colon | Three ways to book: online, by phone or at the desk. |
| Joining two complete thoughts | A full stop | We open at seven. The first loaves are out by half past. |
| Adding a short aside | Commas | Our sourdough, made with rye from Kent, keeps for four days. |
| Adding a longer or less important aside | Brackets | Free delivery in town (orders before noon). |
| Building a dramatic pause | Nothing: cut the drama | Haircuts that last six weeks. |
| Joining a range of numbers or dates | The word "to" | Open 9am to 5pm, Monday to Saturday. |
The last row is a house rule in the GOV.UK A to Z style guide, which asks for "to" in date and time ranges rather than hyphens, en rules or em dashes. It reads better aloud and is clearer to screen readers, which may pronounce the dash or skip it.
Em dash, en dash, hyphen
- Hyphen (-) joins words: well-known, two-factor, a five-page site.
- En dash (–) traditionally marks ranges and some pairings, such as the London–Paris train. In web copy "to" usually does the job better.
- Em dash (—) marks a break in a sentence. British style often uses a spaced en dash for the same purpose; American style often uses a closed-up em dash. Either way, the advice on frequency applies.
Editing a page with too many em dashes
- Count them. Search the page for the character. More than two or three on a whole landing page is worth a look.
- Start with the headline. A dash in a headline is nearly always a pause for effect. Rewrite it as one plain statement.
- Then the cards and lists. Feature cards are where dashes cluster: "Fast delivery, straight to your door" works without one.
- Read each fix aloud. If the new punctuation changes the meaning, you've learned what the dash was hiding.
- Keep the one that earns its place. A genuine interruption in a story or an About page can keep its dash.
Em dash AI writing has company: the same drafts tend to use "not X, but Y" headlines, triplets of adjectives and a recoloured word in the headline. See AI headline clichés, the highlighted word in a headline and the guide to writing website copy that doesn't sound like AI.
Em dashes in Anticode
The Critic keeps em dashes rare on every build. One of its nineteen checks counts the em dashes in a page's visible copy and flags the page when there are more than two. The flag shows up in the build report when an edit or the model's copy adds too many, so you can rewrite those sentences in the visual editor or ask for the change in words, for example "replace the dashes in the feature cards with full stops".
Questions people ask
Do em dashes make writing look like AI?
Not on their own. Frequent em dashes, especially in headlines and short marketing lines, have become one of the patterns people associate with generated text.
What can I use instead of an em dash?
A colon to explain, a full stop to separate, commas or brackets for an aside, and "to" for ranges.
How many em dashes is too many?
On a typical landing page, more than two or three. In a long article, one every few paragraphs is fine if each marks a real interruption.