When it comes to burgers, the topping options are endless. But, somehow, classic cheeseburgers are still holding strong against the competition.

On Sept. 18, burger lovers will celebrate National Cheeseburger Day, and many restaurants are firing up the grill and giving customers some juicy deals to bite into. Ready to join in on the celebration? Here are a plethora of discounts and freebies to choose from.

&pizza

On Sept. 18, &pizza is selling its Sun’s Out Buns Out pizza for $5 (regularly $13.99) all day. The pizza features the chain’s parm-romano sauce, mozzarella, chunks of hamburger, onions, grape tomatoes, lettuce, dill pickles and a burger sauce.

Applebee’s

Applebee’s customers can get one of the three following burgers with fries for just $8.99 at participating locations on Sept. 18: classic bacon cheeseburger, classic cheeseburger and classic Burger. The offer is valid on dine-in and to-go orders.

Bad Daddy’s

Bad Daddy’s customers can order the chain’s All-American Burger with cheese for just $8 on Sept. 18.

Bar Louie

From 11 a.m. — 3 p.m. on National Cheeseburger Day, Bar Louie customers can order the Louie’s Choice Cheeseburger, served with fries or tots, for just $9.95. Pricing and participation can vary across locations.

Buffalo Wild Wings

When Buffalo Wild Wings Blazin’ Rewards members buy one burger on Sept. 18, they’ll get another free. The offer is valid on dine-in, takeout and Buffalo Wild Wings GO orders.

Burger King

Burger King Royal Perks members can score a free cheeseburger with a purchase of $1 or more on Sept. 18.

Carl’s Jr.

Carl’s Jr. rewards members will be treated to half-priced double cheeseburgers on Sept. 18 for in-app, online and in-restaurant orders. The offer is valid on up to four double cheeseburgers per order at participating restaurants. It’s not valid with other discounts and is limited to one offer per registered user.

Dairy Queen

Between Sept. 16 — 22, Dairy Queen customers can get a free double original cheeseburger Signature Stackburger with any app or online order of $1 or more at participating DQ Grill & Chill locations nationwide. The offer is limited to one per customer.

Denny’s

Denny’s rewards members can get 20% off any burger on Sept. 18, including the limited-edition Beetlejuicy Burger. The offer is valid at participating locations for dine-in or online orders and there’s an $8 minimum purchase. The offer can’t be combined with other discounts.

Dog Haus 

Dog Haus will run a buy one, get one free cheeseburger offer for rewards members on Sept. 18. The offer is available in the chain’s app.

Eddie Merlot’s

On Sept. 18, Eddie Merlot’s customers can order Eddie’s Prime Cheeseburger for $15 between 4 — 6:30 p.m. Pricing and participation can vary based on location.

Farm Burger

Grass-fed burger chain Farm Burger is running a build-your-own cheeseburger deal starting at $5 on National Cheeseburger Day.

Farmer Boys

Farmer Boys customers can order the chain’s Big Cheese cheeseburger for just $4 on National Cheeseburger Day between 2 p.m. and close at participating locations while supplies last. The offer can’t be combined with other deals, is limited to two burgers per customer and is available in restaurant or in the drive-thru.

Very Important Farmer (VIF) loyalty members can also get an extra surprise when they scan their receipt.

Friendly’s

Friendly’s Fan Club members can save $2 on cheeseburgers between Sept. 18 — 20.

Hat Creek

Hat Creek customers who order the Little Hat Burger in the chain’s app will score the menu item for just $2 on Sept. 18.

Instacart

Instacart customers can get $10 off their $20 purchase from the National Cheeseburger Day product collection, which features meat, cheese, buns, condiments and more. The offer is valid at select retailers via Instacart.

Krystal

Krystal is currently running a limited-time offer for 12 cheese Krystals for just $15.

The chain also has an online-only offer that entitles customers to a free cheese Krystal with any digital purchase. Use the code CHZKRYSTAL at checkout on Sept. 18 to score the deal.

McDonald’s

McDonald’s customers who order in the chain’s app can enjoy a 50-cent double cheeseburger on Sept. 18.

99 Restaurant & Pub

99 Restaurant & Pub dine-in customers can order the restaurant’s cheeseburger and fries for $6.99 all day on National Cheeseburger Day.

O’Charley’s

O’Charley’s customers can get a cheeseburger and fries for $6, while dining in and ordering online on Sept. 18.

Omaha Steaks

Omaha Steaks is offering the following deals in honor of National Cheeseburger Day:

• Perfect Burger Pack for $99.99
• Custom Burger Experience With Free Brioche Buns for $129.99
• Deluxe Burger Experience for $131.46
• Butcher’s Burger Assortment for $188.46

Red Robin

Between Sept. 17 — 19, Red Robin customers can get a Gourmet Cheeseburger, bottomless side and drink for just $10 (regularly $14.99 or more) while dining in at participating restaurants.

Sonic

For a limited time, Sonic customers can order a quarter pound double cheeseburger for just $1.99.

Smashburger

Smashburger customers can score $5 Classic Singles on National Cheeseburger Day in store, online and in the restaurant’s app using the code CLASSIC24. The offer includes Classic Singles, Classic Single Turkey Burgers and Classic Single Black Bean Burgers.

Sullivan’s Steakhouse

Between 3 — 6 p.m. on Sept. 18, Sullivan’s Steakhouse customers can order the restaurant’s signature beef burger sliders for just $10. Pricing and participation can vary by location.

Wahlburgers

Wahlburgers adult burgers will be 50% off on Sept. 18 at participating locations. The offer is valid in-store and online, and excludes doubles, triples, sandwiches and Smahlburgers. It’s limited to one per customer and can’t be combined with other offers.

Wayback Burgers

Wayback Burgers is running a buy one, get one free deal on its classic burgers on Sept. 18.

Wendy’s

Between Sept. 18 — 22, Wendy’s customers can get a Jr. Bacon Cheeseburger for $0.1 with any purchase while placing an app order at participating restaurants.

Whataburger

On National Cheeseburger Day, Whataburger rewards members who place an app or online order for a patty melt, Sweet & Spicy Bacon Burger or a Whataburger with cheese will be entered for the chance to win free Whataburger for a year. Winners will receive their prize in the form of 52 coupons, which can be redeemed at participating locations.

White Castle

White Castle is running a buy one cheese slider, get one free deal on National Cheeseburger Day. To score the deal, simply use the code SAYCHEESE in the restaurant’s app.

In addition, customers can buy a sack of 10 cheese sliders for $7.99 ($8.99 in New York, New Jersey, Florida and Arizona) through November 10.