On Accident or By Accident – Usage & Examples

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Candace Osmond

Candace Osmond studied Advanced Writing & Editing Essentials at MHC. She’s been an International and USA TODAY Bestselling Author for over a decade. And she’s worked as an Editor for several mid-sized publications. Candace has a keen eye for content editing and a high degree of expertise in Fiction.

When it comes to expressions like “on accident” and “by accident,” because they’re so similar, there’s usually confusion about which one is correct or when you can use each phrase. So, to clear the air, I’ll explain the intent of by accident and show you some usage for its variant on accident.

Is It on Accident or by Accident?

On Accident or By Accident Usage Examples

So, technically, the right phrase to use is “by accident.” It means something occurred unintentionally or without any kind of deliberate plan. But you’ll probably find the alternate version “on accident” sometimes used, just usually in informal speech, because it’s considered non-standard.

By Accident vs On Accident Ngram
By accident and on accident usage trend.

But that doesn’t mean it’s wrong! Language evolves over time, depending on how people use it. If a word or phrase is used by enough people, it will eventually become an accepted form. So, changing the proposition to make the phrase on accident, in this case, doesn’t make a huge difference.

When to Use “on Accident”

As I just mentioned, “on accident” is what we consider the non-standard and less formal version of the two phrases. It’s usually best to avoid using “on accident” in any sort of formal writing you do. But you might encounter “on accident” in casual conversations, especially among the younger crowds.

There is one case where it’s technically correct: when you pair the word “on” with another word to create an adjective for the type of accident. 

  • The two cars collided in a head-on accident. 

When to Use By Accident

“By accident” is the technical standard and correct phrase because it’s more widely accepted to show something has taken place without intent. You can go ahead and use “by accident” in both spoken and written communication, and it will always fit in formal and informal contexts.

By Accident Synonyms

If you’re ever unsure, just use one of these words instead.

  • Unintentionally
  • Inadvertently
  • Mistakenly
  • Accidentally
  • Unknowingly
  • Unwittingly

On Accident and by Accident Examples in a Sentence

On Accident or By Accident Usage Examples 1
  • I spilled my drink on accident when I bumped into the table, and my mom was upset.
  • As Dianna roamed the old building, she discovered the hidden door on accident while searching for a light switch.
  • I’m so sorry! I deleted the file by accident. I didn’t realize it was important.
  • After three years and a new set of keys, my husband found his missing car keys by accident while looking for his old wallet.
  • I spent six hours trying to fix a corrupted file, only to discover that I had a backup saved by accident. Thank goodness!
  • Our dog, Allie, knocked over my grandmother’s vase by accident while playing with the kids in the living room.
  • The mailman put your mail in our mailbox by accident.
  • I actually met my husband by accident during a job interview I wasn’t supposed to be at.
  • Did you know that the life-saving medicine penicillin was actually discovered by accident? I guess there really are happy little accidents!
  • Scientists discovered a whole new solar system by accident while monitoring an asteroid, and now there’s the possibility of life in space.

On or By, It Doesn’t Matter

So, when it boils down to it, there’s no real major difference between “on accident” and “by accident.” It just depends on how technical you want to be. If you’re writing a research paper, an essay, or anything formal, use “by accident,” and you’ll be golden.