Validate Instantly For Difficult Questions

Don’t use inline validation while the user is typing — unless it helps them — like in the case of creating a password, username, or message with a character count.

Here are some benefits of implementing inline validation with real-time feedback just right after the answered question according to the research made by Luke Wroblewski(this research has been conducted 8 years ago!):
• a 22% increase in success rates,
• a 22% decrease in errors made,
• a 31% increase in satisfaction rating,
• a 42% decrease in completion times, and
• a 47% decrease in the number of eye fixations.