When writing about chargers, travel plugs, electronic devices, or even someone who adapts a book for a movie, you may hesitate between adapter and adaptor. The two spellings look almost identical, and it is natural to wonder whether one is a mistake.
The good news is that both adapter and adaptor are correct English spellings. They generally have the same meaning and are pronounced the same way. The main difference is usage preference: adapter is more common in American English, while adaptor is traditionally more common in British English. Major dictionaries also recognize both forms.
Quick Answer
Adapter and adaptor are both correct. They usually refer to the same thing: a person or device that adapts something or makes two things work together.
| Form | Correct? | Common Use | Meaning |
| Adapter | Yes | American English and widespread modern usage | A device or person that adapts or connects things |
| Adaptor | Yes | British English and some other varieties | Same basic meaning as adapter |
For US English, adapter is usually the better choice. For British English, adaptor is a traditional and widely accepted spelling, although adapter is also used.
There is no reliable general rule that says -er refers to a device while -or refers to a person. Both spellings can describe a device or a person.
Meaning and Definition
Meaning of Adapter
Adapter is a noun that generally refers to something that allows two things to work together when they were not originally designed to connect directly.
In everyday English, an adapter is often an electronic or electrical device. For example, a power adapter connects an electronic device to an electrical supply. A USB adapter can allow devices or connections with different interfaces to work together.
The word can also refer to a person who changes an existing work, such as a book or play, so it can be performed or presented in another form.
Definition of Adapter
An adapter is a device used to connect pieces of equipment that would otherwise be incompatible. It can also mean a person who modifies an existing literary or dramatic work for another medium.
For example, a person who changes a novel into a screenplay can be called an adapter. Similarly, a device that allows two different connectors to work together can be called an adapter.
Meaning of Adaptor
Adaptor has essentially the same meaning as adapter. It can refer to a device that connects different pieces of equipment or to a person who adapts an existing work.
The spelling adaptor is especially associated with British English, although it is not restricted to Britain.
Definition of Adaptor
An adaptor is a device or person that adapts something. In technical contexts, it commonly describes a device that connects electrical or electronic equipment that does not directly fit together.
For example, a travel adaptor can allow an electrical plug from one country to work with a socket in another country. Collins also recognizes adaptor and adapter as alternative spellings for this meaning.
Main Difference
The main difference between adapter and adaptor is spelling and regional preference, not meaning.
Both words can be used for:
- A device that connects different pieces of equipment
- An electrical or electronic connector
- A travel device that allows different plugs and sockets to work together
- A person who adapts a book, play, or other work
The biggest practical distinction is American versus British usage.
Adapter is generally preferred in American English. Adaptor is traditionally more common in British English. However, British dictionaries recognize adapter too, so the distinction is a preference rather than an absolute grammatical rule.
Adapter vs Adaptor at a Glance
| Feature | Adapter | Adaptor |
| Spelling | -er | -or |
| Meaning | Same basic meaning | Same basic meaning |
| Pronunciation | Generally the same | Generally the same |
| American English | More common | Less common |
| British English | Used | Traditionally common |
| Refers to a device | Yes | Yes |
| Refers to a person | Yes | Yes |
| Correct English | Yes | Yes |
Which One Is Correct?
Both adapter and adaptor are correct.
You should not treat adaptor as a misspelling of adapter, or vice versa. Both forms are established English words.
If you are writing in American English, choose adapter because it is the more familiar spelling for most US readers.
If you are following British English, adaptor is a natural traditional choice. However, adapter is also acceptable in British usage.
The important thing is to consider your audience and remain consistent. If your document is written in American English, using adapter throughout will usually provide the most natural style.
Grammar and Usage
Both adapter and adaptor function primarily as countable nouns.
They can be used in singular and plural forms:
- one adapter
- two adapters
- one adaptor
- two adaptors
The plural ending follows normal English spelling.
Singular Usage
Use adapter or adaptor when referring to one device or person.
I need an adapter for my laptop.
She is the adaptor of the novel.
Plural Usage
Use adapters or adaptors when referring to more than one.
The store sells several types of adapters.
We tested three different adaptors.
The choice of spelling does not change the grammatical structure of the sentence.
American and British Usage
For a US audience, adapter is generally the safest choice:
Please bring your laptop adapter.
For a British audience, adaptor may be more traditional:
Please bring your laptop adaptor.
Neither sentence is grammatically wrong. The difference is mainly spelling preference.
How to Use Adapter and Adaptor
Use Adapter in US English
If your audience primarily uses American English, adapter is normally the preferred spelling.
Common combinations include:
- power adapter
- laptop adapter
- USB adapter
- network adapter
- wireless adapter
- travel adapter
- HDMI adapter
- lens adapter
For example:
My phone adapter stopped working.
You may need a USB adapter for this device.
I bought a travel adapter before my trip.
Use Adaptor in British English
Adaptor is a common traditional spelling in British English.
For example:
I bought a new travel adaptor.
The adaptor connects the device to the power supply.
This adaptor works with several types of plugs.
However, you may also see adapter in British writing, especially in modern technical and international contexts.
Examples
Examples of Adapter
- I need a power adapter for my new laptop.
- The USB adapter connects the two devices.
- She packed a travel adapter for the trip.
- This network adapter supports a faster connection.
- Please check whether the adapter is compatible with your phone.
- The camera requires a special lens adapter.
- He forgot to bring his laptop adapter to the office.
- The wireless adapter was easy to install.
- We purchased an HDMI adapter for the presentation.
- The filmmaker worked with an adapter who turned the novel into a screenplay.
Examples of Adaptor
- I need a travel adaptor for this socket.
- The electrical adaptor connects the device to the mains supply.
- She bought a new laptop adaptor.
- This adaptor allows the two connectors to work together.
- The technician replaced the damaged adaptor.
- The book’s adaptor made several changes to the original story.
- Check the adaptor before connecting the equipment.
- The company sells several types of power adaptors.
These examples demonstrate an important point: adaptor is not limited to electrical devices, and adapter is not limited to American English. Both spellings can have the broader meaning of something or someone that adapts.
Common Mistakes
Mistake 1: Thinking Adaptor Is Incorrect
Some writers assume that adapter is simply a spelling error.
That is incorrect. Adaptor is a legitimate English spelling and is recognized by major dictionaries.
Correct:
I bought a travel adaptor.
Mistake 2: Assuming Adapter Is Only American
Although adapter is strongly associated with American English, it is also used elsewhere.
British English can use adapters, particularly in modern technical and international contexts. Therefore, it is too strong to say that the adapter is exclusively American.
Mistake 3: Changing the Meaning Based on the Ending
Some people believe adapter refers to a device while adaptor refers to a person. There is no general standard rule supporting that distinction.
Both spellings can refer to a device or a person.
Mistake 4: Switching Spellings Unnecessarily
A document can look inconsistent if it uses both forms without a reason.
For example:
The laptop adapter connects to the travel adaptor, and another adapter is included.
This is not grammatically incorrect, but if all three words refer to the same general type of device, consistent spelling may be preferable.
Choose the form that suits your audience and use it consistently.
Linguistic Insight
The difference between adapter and adaptor is an example of spelling variation in English. English contains many words that have developed alternative spellings across regions and historical traditions.
The endings -er and -or can both appear in English nouns describing a person or thing associated with an action. As a result, it is not unusual for related forms to develop different spelling preferences.
In the case of adapter/adaptor, modern dictionaries do not treat the two as completely separate words with fundamentally different meanings. Instead, they recognize them as alternative forms.
Regional variation is particularly important here. American English generally favors adapters, while British English has traditionally used adapters more often. At the same time, modern English usage is not perfectly divided by national borders.
Technology has also encouraged the widespread use of adapters. Terms such as power adapter, USB adapter, and wireless adapter are common in international technical communication.
This means that spelling preferences can depend on region, industry, publication style, and established terminology.
Usage Tips
Here are some simple ways to remember the difference:
- For American English: prefer adapter.
- For traditional British English: adaptor is a natural choice.
- For international technical writing: adapter is often the clearest and most familiar option.
- Do not assume the adapter is wrong.
- Do not assume the two spellings have different meanings.
- Stay consistent within the same document.
A useful memory aid is simple: adapter with -er is the form you will most often want for US English.
If you are writing for a specific company, publication, or organization, follow its established style if it has one.
Expert Suggestion
For most US English writing, use adapters.
This is especially useful for websites, product descriptions, technical articles, professional documents, and educational content intended for American readers.
If you are writing specifically in British English, an adapter is perfectly acceptable. However, do not change every occurrence merely because you see the alternative spelling. The goal is not to find a universally superior form. The goal is to choose the spelling appropriate for your audience and use it consistently.
For content writers and students, the easiest rule is:
Use adapter in American English; use adapter when following a British spelling preference.
Remember that both are correct.
Summary
Adapter and adaptor are both correct English words. They have the same basic meaning and can refer to a device that connects different pieces of equipment or to a person who adapts an existing work.
The primary difference is spelling preference. Adapter is generally more common in American English, while adapter is traditionally more common in British English. However, both forms can appear in British and international usage.
Neither spelling should automatically be considered a mistake. The best choice depends on your audience, style guide, and context.
If you are writing for a US audience, adapter is usually the best choice. If you are following British English, adaptor is also a natural and established option.
Most importantly, do not invent a difference in meaning between the -er and -or spellings. In ordinary usage, they are alternative spellings of the same word.
Frequently Asked Questions
Is adapter or adapter correct?
Both adapter and adaptor are correct. They are alternative spellings of the same word. Adapter is generally preferred in American English, while adapter has traditionally been more common in British English. The choice is mainly a matter of regional spelling preference rather than grammatical correctness.
What is the difference between adapter and adaptor?
The main difference is spelling and regional preference. Adapter is more common in American English, while adapter is traditionally more common in British English. Their meanings are essentially the same, and both can refer to a device or a person that adapts something.
Is adaptor a British spelling?
Yes. Adaptor is a well-established British spelling, although British English also uses adapter. Therefore, it is better to describe adapter as a traditional or common British variant rather than saying that it is exclusively British.
Is the adapter American English?
Adapter is the more common spelling in American English. It is widely used for electronic devices, electrical connectors, and people who adapt written works. The spelling is also used outside the United States, so it should not be considered exclusively American.
Can adaptor refer to a person?
Yes. Adaptor can refer to a person who adapts an existing work, such as a novel, play, or story for another format. Adapter can have the same meaning. The spelling does not create a fixed distinction between people and devices.
Can adapter refer to an electrical device?
Yes. Adapter commonly refers to an electrical or electronic device that connects equipment or allows components with different connections to work together. Examples include power adapters, USB adapters, laptop adapters, and travel adapters.
Are adapter and adaptor pronounced the same?
Yes. In standard usage, adapter and adaptor are pronounced essentially the same way. The difference is in spelling, not normally in pronunciation. The ending changes from -er to -or, but this does not create a meaningful pronunciation difference in ordinary speech.
Which spelling should I use in American English?
Use an adapter for American English. It is the more familiar and conventional spelling for US readers, especially in technical contexts. For example, write power adapter, laptop adapter, or USB adapter when producing content specifically for an American audience.
Which spelling should I use in British English?
You can use adapter in British English, particularly if you want to follow a traditional British spelling preference. However, adapter is also accepted and used in British English. If a publication or organization has a preferred style, follow that style consistently.
Is it wrong to use both adapter and adaptor?
Not necessarily. Both are correct, so using either spelling is grammatically acceptable. However, switching between them without a reason can make your writing look inconsistent. For polished professional writing, choose one spelling based on your audience or style guide and use it consistently.
Does adapter mean a device while adaptor means a person?
No. There is no general rule that assigns different meanings to the two spellings. Both adapter and adaptor can describe a device or a person. The difference is primarily spelling preference, particularly across varieties of English.
Which spelling is better for SEO content?
For content targeting a US audience, adapter is usually the better primary spelling because it aligns naturally with American English. If your audience is British, adaptor may be appropriate. You can mention the alternative spelling naturally in the article without repeatedly forcing both terms into every sentence.
Is a travel adapter or travel adapter correct?
Both are correct. Travel adapter is especially common in American English, while travel adapter is also widely used in British English. Both refer to a device that helps an electrical plug work with a different type of socket or connection.
Should I use adapter or adapter in formal writing?
Either spelling can be correct in formal writing. The best choice depends on the variety of English you are following. For formal writing, use an adapter. For a British English document, adaptor is acceptable. Consistency is more important than treating one spelling as universally correct.
Henry King is a dedicated writer with a passion for making English easy, practical, and enjoyable. At Grammer Lord, he creates clear guides, useful examples, and engaging ideas that help readers understand language and improve their writing. Henry enjoys turning complex ideas into simple explanations that anyone can follow. He believes learning should feel natural, useful, and inspiring. Through his work, he aims to help students, writers, and everyday readers discover better ways to use words, express ideas, and communicate with confidence.
