Both "Thank you to everyone" and "Thank you everyone" are grammatically correct, but they are used in slightly different contexts.
"Thank you to everyone": This phrase is commonly used when you want to express gratitude to a specific group of people or individuals. It is often used when you are acknowledging multiple people for their help, support, or participation in something. For example, "Thank you to everyone who attended the event" or "Thank you to everyone who contributed to the project."
"Thank you everyone": This phrase is a more general and informal way to express gratitude. It is used when you want to thank a broader audience or a larger group of people without specifying individuals. For instance, you might say "Thank you, everyone, for your kind wishes on my birthday" or "Thank you, everyone, for being here today."
Both expressions convey gratitude, but the choice between them depends on the context and the level of specificity you want to convey in your thank-you message.