In Line or Inline or In-Line?

The term in line as two words is an idiom that means something follows a principle or is similar to something else. E.g., “Their service was not in line with expectations.” Also, in-line is correct as a compound adjective. E.g., “The in-line program functions stopped working.”

There are three correct ways to spell the term in line; however, in line is the most common version.

The Cambridge Dictionary lists the two-word version, in line, as an idiom meaning something follows a particular set of rules or that it is similar or dissimilar to something such as an expectation.

For example, in this sentence, we are saying there is a difference between the level of service provided and the expected level.

  • I would like the service at the hotel to be more in line with what we discussed.

Furthermore, the Cambridge Dictionary contains the hyphenated version, in-line, which is an adjective you will commonly see in finance, IT, or technology-related texts.

This word has a similar meaning to the idiom and relates to how things behave compared to expectations. Also, it can mean something that is contained within a process, system, or tool.

  • Our in-line predictions outweighed our incorrect forecasts in terms of performance.

Furthermore, inline as one word with no hyphen is also a correct spelling version. You can use this version to refer to the sport of inline skating or the main section of a page, i.e., not the margin.

  • Please make all notes during the exam inline rather than as footnotes.

Are you still in doubt about how to use the three different spelling variations of in line? Keep reading the rest of the page to learn and see some helpful examples.

In Line

The non-hyphenated term in line is a correct idiom that you can use to say that something is similar or different from something else, such as a set of rules or expectations.

In line is the most common spelling variation.

For example, this sentence shows that the text needs to be the same as the rules.

  • Your text should be in line with the above rules concerning hyphens.

Here are some more examples in case you are still in doubt:

  • Your actions should be in line with the company’s code of ethics.
  • Make sure your research is in line with the guidelines set by the academic committee.
  • The budget allocation should be in line with the project’s long-term goals.

Furthermore, another everyday use for the two-word term refers to waiting in a line or queue or for someone being next for something.

For this type of sentence, you should not use a hyphen.

Here are four examples that should help you understand more about the context:

  • I waited in line for over an hour then the store closed.
  • He is next in line to his father’s business empire.
  • We stood in line for the concert tickets, only to find out they were sold out.
  • As the eldest sibling, she is next in line to inherit the family estate.


The hyphenated one-word term in-line is a correct compound word you will often see in texts relating to technology, audio, finance, and other subjects.

Its meaning can vary somewhat depending on what it modifies. However, in a general sense, it means something similar to within or inside.

For example, in this sentence, in-line refers to the volume control being in the microphone rather than in the amplifier.

  • The in-line volume control in the microphone is state-of-the-art.

Also, here are a few more examples to show in-line used in this context:

  • The printer comes with an in-line stapler for easier document management.
  • The car’s in-line fuel injection system improves its overall performance.
  • The in-line air filter ensures that only clean air circulates through the system.
  • This laptop has an in-line power adapter that makes it more compact and portable.

The adjective in-line is not massively common, but it is still correct, and you can use it in the proper context.


The term inline as one word with no hyphen is correct and has two principal uses.

The first is to refer to the area of a page inside the line. The line, in this case, represents the margins of the page, so anything inside the margins of a page can be described as inline.

  • We will consider all text written inline during the grading process.
  • The comments you added inline in the document were very helpful for understanding the context.
  • Please make any necessary corrections inline so we can easily track the changes.
  • The code includes inline annotations to clarify the more complex algorithms.

Also, people often use inline to refer to the sport of inline skating. However, you can also refer to it as in-line skating, as both versions are acceptable.

  • She was the local inline skating champion for 2022.
  • He’s been practicing for months to compete in the national inline skating competition.
  • The park has a dedicated track for inline skating, making it a popular destination for skaters.