---
title: "What is Opacity in CSS (Cascading Style Sheet)?"
description: "What is Opacity in CSS (Cascading Style Sheet)?"
author: "Abhishek Srivasatava"
published: 2016-10-14
updated: 2020-09-17
canonical: https://www.mindstick.com/interview/23086/what-is-opacity-in-css-cascading-style-sheet
category: "css-css3"
tags: ["css"]
reading_time: 2 minutes
---
# What is Opacity in CSS (Cascading Style Sheet)?
It can be define as the transparency of any image, block etc.\
For defining opacity in CSS we need to remember keyword OPACITY ( Filter it is used in internet explorer.)
```
Img {Opacity: 0.5Filter: alpha (opacity =50)}
```
Opacity value can be in between 0-1.
It can be use for hover case.
How it can be use in the CSS programming?
```
Img:hover{Opacity:1.0}
```
**Writing some text in inside transparent box**
```
Text of transparaent block
```
\
## Answers
### Answer by Abhishek Srivasatava
It can be define as the transparency of any image, block etc.\
For defining opacity in CSS we need to remember keyword OPACITY ( Filter it is used in internet explorer.)
```
Img {Opacity: 0.5Filter: alpha (opacity =50)}
```
Opacity value can be in between 0-1.
It can be use for hover case.
How it can be use in the CSS programming?
```
Img:hover{Opacity:1.0}
```
**Writing some text in inside transparent box**
```