O with Slash / O with Line Through It (Ø): How to Type & Use
Have you ever seen an “O with slash through it” (Ø or ø) and thought, “Wait, what is that? Is it a zero? Is it a special symbol? Or just a fancy letter?”
You’re not alone. This letter O with line through it confuses many people because it looks like both the letter O and the number 0 (zero). But the truth is: the O with line through it symbol is a real letter with a unique history, sound, and meaning.
In this guide, I’ll break it down in plain English:
- What the O with slash (Ø) actually means.
- Where it comes from (Norway & Denmark).
- How to type O with slash on any device (Windows, Mac, phone)
- The difference between Ø, zero with a slash, and other similar symbols
What is the “O with a Slash” (Ø)?
The letter O with line through it, written as Ø (uppercase) or ø (lowercase), is a real letter — not just a stylized “O”.
- In the Norwegian O with slash and Danish O with slash, it’s considered a separate vowel in the alphabet.
- Think of it like Spanish “ñ” or German “ü” — it’s still a letter, but with its own sound.
- Fun fact: in the alphabet, Ø comes after Z.
So if you’ve ever wondered, “What is an O with a slash through it?” — it’s not a design choice. It’s an actual letter.
O with Slash Meaning (Ø)
So what does O with slash mean?
- In Norwegian and Danish: Ø is pronounced kind of like the “i” in “bird” or the “u” in “burn.” It’s not exactly the same, but close enough if you’re just learning.
- In phonetics (IPA): It represents a rounded front vowel. That’s a fancy linguistic way of saying it’s a unique sound you don’t usually hear in English.
- In math and science: Sometimes people mistake Ø for other symbols (like diameter ⌀ or empty set ∅), but those are different symbols entirely.
So the bottom line: Ø = a real letter with its own sound, not just a stylistic choice.
How to Type O with a Slash (Ø) on Any Device
Typing the O with slash alt code is easier than you think.
On Windows (Alt Codes):
- For capital O with line through it (Ø), hold down the Alt key and type 0216 → Ø.
- For o with line through it lowercase (ø) or small o with line through it, use Alt + 0248 → ø.
On Mac:
- Press Option + O for the lowercase ø
- Press Option + Shift + O for the uppercase Ø.
On Linux:
- Linux users can rely on the Compose key. Just press Compose, then type
/followed byo, and it will give you ø.
On iPhone/Android:
- Hold down the letter O on the keyboard, and a menu pops up.
- Slide to choose ø.
Unicode Codes:
- Ø (uppercase): U+00D8
- ø (lowercase): U+00F8
So next time you see someone drop “Ø” in a message, you can impress them by typing it back.
O with Line Through It Copy and Paste
If you don’t want to mess with codes, here’s a quick copy-paste option:
| Letter | Name | Copy |
|---|---|---|
| Ø | Capital O with Line Through It | |
| ø | Small o with Line Through It | |
| Ö | Capital O with Umlaut | |
| ö | Small o with Umlaut | |
| ∅ | Empty Set Symbol | |
| ⌀ | Diameter Symbol |
Zero with a Slash vs O with a Slash
Many people ask, “Is O with a slash a zero?” The answer: No.
This is where people get tripped up. Ø is not the same thing as “0 with a slash”.
- Ø (letter O with slash) → Used in languages like Norwegian and Danish.
- 0̸ (zero with slash) → Just a way to make sure you don’t confuse the number zero with the letter O.
- ∅ (empty set symbol) → Used in math to mean “nothing” or “null.”
- ⌀ (diameter symbol): Used in engineering drawings.
They all look similar, but their meanings are completely different.
So if you’re asking, “What does the O with a slash through it mean?” → It’s a vowel, not a number.
Similar Symbols That Get Confused with Ø
Here’s the cast of lookalikes that often get mistaken for our friend Ø:
- ⌀ (Diameter symbol): Used in engineering and technical drawings to show diameter size.
- ∅ (Empty set): In math, means “nothing.”
- 🚫 (Circle with a slash): The “no” or “prohibited” sign (like 🚭 no smoking).
- (/) Slash symbol: Just your regular old slash.
So while they may look like Ø at a quick glance, each has a totally different purpose.
Ø vs Ö vs ∅ vs ⌀
| Symbol | Name | Usage | Unicode |
|---|---|---|---|
| Ø / ø | Letter O with line through it | Letter in Scandinavian alphabets | U+00D8 / U+00F8 |
| Ö / ö | O with umlaut | Used in German, Swedish, Finnish, etc. | U+00D6 / U+00F6 |
| ∅ | Empty set | Mathematics, logic | U+2205 |
| ⌀ | Diameter symbol | Engineering, technical drawings | U+2300 |
Quick FAQ
How to type O with slash?
On Windows, press Alt + 0216 for Ø and Alt + 0248 for ø. On Mac, use Option + O (ø) or Option + Shift + O (Ø).
How to type ø?
On Windows, use Alt + 0248. On Mac, press Option + O. On phones, hold the “O” key and select ø.
How to type O with slash on phone?
Long-press the “O” key on your iOS or Android keyboard, then slide to choose ø.
What does a zero with a line through it mean?
That’s a slashed zero (0̸), used in computing to distinguish the number 0 from the letter O.
What alphabet uses Ø?
Ø is part of the Danish, Norwegian, Faroese, and Southern Sámi alphabets.
What does “o” with a slash mean in sets?
In set theory, the symbol ∅ (which looks similar) means empty set. It is not the same as Ø.
Final Thoughts
The O with a slash (Ø) isn’t just some random design — it’s a letter with real history, meaning, and pronunciation. Whether you’re learning Norwegian, trying to type it in a name, or just stumbled across it online, now you know:
- It’s not a zero.
- It’s not just a circle with a line.
- It’s a letter O with slash that carries meaning, pronunciation, and cultural value.
For more detailed information about Ø, you can visit its Wikipedia page
- Related
- Learn about N with Tilde (Ñ / ñ)
- Type ü (U with Two Dots)
- Learn about O with Accent Mark