1.Use Wi-Fi wherever possible
Whenever you’re in the house, or at the office, there’s a good chance you can switch from your mobile data connection to Wi-Fi. Make sure you get into the habit of doing it, and you can make huge savings on the data you’re using. It’s as simple as tapping Wi-Fi in your Settings menu. If you leave Wi-Fi turned on, and you’ve connected to a router before, then it should connect automatically when it comes into range.

Many carriers also offer Wi-Fi hotspots you can connect to when you’re out and about, so take advantage of them. For example, AT&T has a Wi-Fi hotspot locator map and an AT&T Smart Wi-Fi app for Android, which is supposed to make it easy to automatically connect, although reviews are mixed. If you’re in a city you can probably save a fair bit of data by learning where your carrier’s hotspots are.
It’s also worth checking around you for free Wi-Fi. The free app Wi-Fi Finder (Android, iOS) takes all the pain out of finding Wi-Fi spots near you.
Untitled

2. Compress your data
Check out the Onavo Extend app (Android, iOS). It is designed to compress your data and potentially extend your data plan by up to five times. It doesn’t work with streaming audio or video apps, and it doesn’t work with VoIP apps, but it will help reduce the impact of images and text. It gives you a breakdown of which apps are using your data, lets you create a universal cache, and helps you choose the balance you want between image quality and data savings. It’s free, so it’s worth giving it a try if you find yourself running out of data all the time.

3. Limit background data
One of the main drains on your data is probably going to be background syncing, when an app like Facebook grabs an update, or your phone checks to see if there’s any new email on your server. Think about what you actually need updated in real-time. Can you reduce the frequency of push notifications, or just set apps to update manually so they only grab new stuff when you actually open them? This can save you a lot of data, not to mention battery life. You’ll generally need to do it via the Settings menu of the app in question.

In iOS, you can also go to Settings > Cellular and scroll down to see a list of apps under Use cellular data for. Toggle off anything that isn’t essential.

In Android, take a look under Settings > Wireless & Networks > Data usage and tap on an app to find the option to Restrict app background data.

You should set some things to only update via Wi-Fi, such as app updates. This is an important one because app updates can be huge, and if you’ve set them to update automatically then you could end up using a surprising amount of data.

4.TURN OFF ‘WIFI ASSIST’
Wi-Fi Assist eats away at your data allowance

To switch it off, go Settings > Mobile Data > Scroll down to the bottom > Switch ‘WiFi Assist’ to white.
2
22

5.DISABLE BACKGROUND APP REFRESH
When you use the Cosmo app, you don’t have to refresh to receive the latest news? It’s because the app has been doing it in the background and consequently eating up the data when you’re not even using it.

To turn this off, go Settings > General > Background App Refresh > Turn it off completely or see which apps are using it the most.

background

6.FIND OUT WHICH APPS ARE USING YOUR DATA
Many apps are eating your data. it’s good to know how much data each app eats per month – and what things to need to turn off when you’re running low.
Go to your settings > Go to Mobile > Reset Statistics

4

7.UPDATING APPS
Updating your data is a big problem, It is losing data quickly. Even it is worst if it is automatically.
To switch it off, Go to Settings > iTunes and App Store > Switch Use Mobile Data to off.

5

8.FIND OUT HOW MUCH DATA YOU ACTUALLY NEED
Calculate how much data you need every month. Choose best plan accordingly and save your money.

9.DOWNLOADING PICTURES FROM WHATSAPP
Downloading and watching 10 videos, your sister sent you of your pet is might be so cute, but it is destroying your data.
To turn it off, go settings > Scroll down to WhatsApp > Switch Mobile Data to off. 
6