Move the opening consonants to the end, add ay, and keep the capitals and punctuation in place.
Words that start with consonants move their first consonant sound to the end and gain ay, so pig becomes igpay and string becomes ingstray. A leading qu travels together, as in quick becoming ickquay. Words that begin with a vowel get way added by default, and you can pick yay, hay or just ay instead because dialects differ.
Capitalization is preserved, so Hello becomes Ellohay, and punctuation stays attached to the end of its word. Decoding reverses the pattern, but since Pig Latin loses information, a few words can come back slightly different from the original.
Pig Latin is a spoken children's game with no official standard. That is why the suffix for vowel words varies between way, yay and hay.
At the start of a word y acts like a consonant, so yellow becomes ellowyay. Inside a word it acts as a vowel, so rhythm becomes ythmrhay.
No. When a word ends in ay, the tool guesses where the moved consonants began. Words like way or say can decode ambiguously.