Extensible vs. Extendible – What’s the Difference?

How do we describe an item that can extend in size or shape? Should we say “Extensible” or “Extendible”?

Let’s look at both words, to figure out their meanings and which is the most adequate way to apply them to how we communicate.

Extensible vs. Extendible – What’s the Difference?

“Extensible” refers to an item that can expand with the use of an extension. “Extendible” is actually a common misspelling, and the correct spelling for it is “Extendable” (with an “a”, not an “i). “Extendable” is the opposite of retractable, and it means an item can expand on its own.

Extensible vs. Extendible

Take a look at the sentences below:

  • The camera is extensible, as you can add various different features to it.
  • The legs of the camera tripod were extendible. (incorrect)
  • The legs of the camera tripod were extendable.

Although both words indicate how items can be expanded, the difference lies in the form through which the items are capable of doing so.

Let’s look at each word separately, to understand those differences in meaning.


“Extensible” can be used to describe items that can be expanded by the addition of extra parts (which we call add-ons). It can also relate to computer programs that can be adjusted to better suit the needs of an user.

Looking at The Cambridge Dictionary we notice it favors the tech concept.

Let’s look at some examples of the word “Extensible” applied to sentences:

  1. The computer program is extensible through add-ons.
  2. The game is extensible, as you can add various new features.
  3. The table was extensible: it had hidden parts that when added, allowed for a larger group to share a meal.
  4. The binoculars Carl got are extensible: if you add more parts, you can see even farther away.
  5. The model is readily extensible and can become more modern if you need it to.

The word “Extensible” is always connected to the idea that the item (or product, or software) can expand easily with the addition of new parts that attach to it.

In other words, the product has the capability to be expanded, but not on its own.


“Extendible” isn’t a word. It’s, in fact, a misspelled form of “Extendable”. Basically, “Extendable” is something that can be extended and made longer. It’s not necessary to add more parts in order to do it, and it’s usually a feature of the product.

The Cambridge Dictionary has a definition for “Extendable” (and not for “Extendible”, as expected) that agrees with the one above. It adds that “Extendable” may also indicate items that can be made to last longer.

Take a look at some examples of “Extendable” below:

  1. The legs of the chair were extendible. (incorrect)
  2. The legs of the chair were extendable.
  3. The antenna on the device is extendable.
  4. Is your hose extendable? I can’t reach the end of the lot.
  5. The box had an extendable lid, in case we needed it to fit a bigger item.
  6. Johnny purchased an extendible sofa, very convenient for movie nights.

When you think about an “Extendable” product, you should think about something that has the capacity to extend without the need to add more parts to it.

Which Is Used the Most?

Which of those words do you think is more commonly used? Could it be “Extendible”, the misspelled form? Or would it be “Extensible” or “Extendable”?

Let’s look at the graph from Google Ngram Viewer to find out.


“Extensible” is the most used word, perhaps because it has a meaning connected to the tech industry, that it’s ever growing and certainly has a lot of impact on how we communicate.

“Extendable” comes second. And “Extendible” comes third – as we would expect, considering it’s an incorrect form of the word “Extendable”.

Those are difficult words. But which one is your favorite? Which of the two correct ones would incorporate into your vocabulary more easily?

Final Thoughts

Keeping it simple and objective, “Extensible” describes things that can expand if you add more parts to it. “Extendible” doesn’t exist, and the correct form to spell it is “Extendable”. An “Extendable” item can be extended (made longer) by itself, with no need to add more parts.