How do you know if a restaurant is “bad” once you walk in?

Foodies have revealed the dead giveaways that your favorite eatery is a “bad restaurant” and the warning signs to watch out for when a place is going downhill.

Everyone has had subpar dining experiences in their life, but there are certain red flags you can learn to spot, the experts say.

Kimberly Tristan, a Texas pastry chef, asked her fans why they realized they were in a second-rate restaurant.

Certain warning signs are subtle, such as a clean dining room but a dirty bathroom, a large amount of menu items, and wall-to-wall carpeting.

Others are more eye-catching: the chef picking his nose, garbage bags at the entrance or several empty tables.

Whether you’re choosing a place for the perfect date night or a corporate party, you should always try to explore the restaurant before tucking into a meal.

Bad customer service

‘It’s always good practice to greet customers – I understand when a restaurant is busy, but there’s no excuse not to say a simple ‘hello’ otherwise.

“The wait staff had a terrible attitude and took forever to take our orders and bring us drinks.”

“Super inattentive waiters are always signs of bad food,” revealed another.

‘I once saw a chef picking his nose. I left immediately.’

Plenty of choice

“When there are a lot of items on the menu you just know they are not cooked fresh and the staff are just heating up frozen meals,” one former chef wrote.

“Most photos on menus tend to be just stock photos — red flag.”

Food is served cold

If your hot appetizer is served at room temperature or with a cold core, it’s a very bad sign.

“It either means they left the dish out forever or didn’t even bother to reheat it properly because it was frozen.”

“Cold food shows how little the staff cares about the customers.”

Certain warning signs are subtle, such as a clean dining room but a dirty bathroom, a large number of menu items, and several empty tables

Bad hygiene

One woman recalled every foodie’s worst nightmare: “(You know a restaurant is bad) when a mouse walks over your feet.”

“When your feet stick to the ground – that’s so gross.”

“If a restaurant is carpeted, it means they’re not vacuuming nearly enough.”

“One time we were in a restaurant and we could see into the kitchen and it was rubbish on the floor,” said one man. ‘We have left.’

“Many restaurants use dimmed lighting that hides all the dirt everywhere.”

Some were even plagued by clipped toenails on their tables and a trail of crumbs on the chairs.

‘A restaurant where I once set the table with the dirty dishes. They kept apologizing saying it was messy because we just missed the crowds – but the place was empty except for us.’

The restaurant is empty

While it’s not always a red flag if a restaurant is empty – meal times and rush hours can vary – if a restaurant is always empty, it doesn’t bode well.

“There’s a place in town that only attracts tourists because they don’t know any better,” said one man.

“I never go anywhere that the locals don’t trust.”