About the Validators
Validators check that your data is correct before it causes problems: validate JSON syntax, test regular expressions against real samples, check email address format and compare two texts for differences. Catching errors early prevents failed API requests, broken forms and bad data in your database.
Validate Early
Validate data where it enters your system: on forms, API endpoints and file imports. Client-side checks give users instant feedback, but always repeat validation on the server, because browser checks can be bypassed.