On this page you will be able to download latest iOS firmware of iPhone 5s. You can use it for restoring your device into its original conditions. Flashing process will delete all data and content, including videos, songs, photos, contacts, and other information, and will restore all settings to their factory condition. Updating your device doesn't affect your content, settings or other information. In either case, backing-up your content in iTunes or iCloud is recommended. There are other flash tools and boxes which you can use as a flasher. You will need to always flash your phone with updated firmware. Flashing of phone does at those stage if pone is working slow or completely break with the reason of its corrupted firmware.
After downloading the desired firmware, connect the device to your computer and select it in iTunes. Mac users hold down the Option key, while Windows users should hold down the Shift key. Then click on the Update or Restore button, select the IPSW file you recently downloaded and click Choose. Your device should now begin to update. Take note that certain browsers may change the ipsw-file into a zip-file. If this should occur, just rename it to end in .ipsw and iTunes will recognize it. Some times your phone will be going to dead if you are going to flash it with corrupted or outdated firmware. You can manage below download links to get the latest firmware of your phone.
