How to know if iPhone is fast charging

Hello Vamsee@123,

Thanks for reaching out using Apple Support Communities!

We see you have a question about fast charge and your device; we're happy to assist.

There isn't an extra notification, but as long as you meet all requirements for fast charge, it will fast charge when it's connected to the charger.

This Apple Support page has the full details for how to Fast charge your iPhone

We hope this helps answer your question to ensure fast charge is working for your device.

Cheers!

On the charger itself, you will see some text that states how many watts the charger provides. You'll see something like "5w" or "12w" or "20w" or some variation of that.

5w is the original charge rate. Generally anything in the double-digits is basically a fast-charger.