You do not need a full Blackstone to smash burgers on a flat top.
A griddle insert drops onto the grates of the grill you already own and turns it into a flat top cooking station in 60 seconds. Perfect for smash burgers, breakfast bacon and eggs, teppanyaki-style veggies, fried rice, and every small food that normally falls between the grates. This guide covers six flat top options compatible with selected Weber, Char-Broil, Nexgrill, Camp Chef, Traeger and other setups – check your grill size before ordering.
Disclosure: PitPrimer earns commission on qualifying purchases through Amazon Associates and select brand campaigns. Product fit varies by grill model; check size before purchase.
Why a flat top griddle earns its space on the patio
Regular grill grates are optimized for one thing: searing thick cuts of meat with visible grill marks. That is exactly the wrong tool for:
- Smash burgers (need continuous flat contact to develop crust)
- Breakfast items (bacon, eggs, pancakes fall between grates)
- Small vegetables (peppers, onions, mushrooms slip through)
- Teppanyaki-style cooking (fried rice, thin noodles, small shrimp)
- Delicate proteins (fish fillets, shrimp)
A dedicated flat top griddle from Blackstone runs $300-800 and takes up permanent patio space. A griddle insert costs $60-90, sits on top of your existing grill grates, and stores in a drawer. For most backyard cooks, an insert is the correct answer.
Our top picks by scenario
- Best value (small grill): Uniflasy 17×13 metal griddle – about $65, fits selected Weber, Char-Broil, Camp Chef, Nexgrill, Kenmore, and other compact grills
- Best cast iron (medium): Uniflasy 23×16 porcelain enamel cast iron – superior heat retention, best for searing
- Best large surface: Uniflasy 25×16 flat top insert – room for 6-8 smash burgers or family breakfast
- Best nano-ceramic (easy cleanup): Uniflasy 25×16 nano-ceramic – nonstick surface makes eggs and pancakes trivial
Compatibility note: These are compatible with selected grill setups. Measure your grill (inside grate to inside grate) before ordering.
1. Best value small: Uniflasy 17×13 metal flat top griddle
The go-to entry option. At 17″ x 13″, this fits inside the majority of compact and mid-size gas grills – selected Weber Spirit, Char-Broil Classic, Camp Chef, Nexgrill, Kenmore, Dyna-Glo, and Expert Grill units. Raised sidewalls keep food from sliding off during flipping. Hollow side panels support air circulation for even heating. Cook surface accommodates 4-6 smash burgers or a full breakfast for two.
Use cases: weeknight dinners, breakfast on weekend camping trips, tailgating, small-batch teppanyaki.
- Uniflasy 17″x13″ metal flat top griddle
- Uniflasy 17″x13″ cast iron with nano-ceramic nonstick (alternative with easier cleanup)
2. Best cast iron medium: Uniflasy 23×16 porcelain enamel
Cast iron is the classic griddle material for a reason – it retains heat better than sheet steel, which means you get better crust on smash burgers and steak bites. This Uniflasy 23×16 uses porcelain enamel coating that helps with food release and cleanup while preserving the cast iron heat retention.
Fits selected Weber Genesis II, Nexgrill, Char-Broil, Cuisinart, Traeger, Char-Griller, Z GRILLS, and other gas grill setups. Extra high sidewalls, reinforced back ribs, and side handles for lifting. Larger cooking surface (368 square inches) handles family meals with room to spare.
Also functional on 4-burner range stove tops if you want an indoor flat top option in winter months.
3. Best large surface: Uniflasy 25×16 flat top griddle (three variants)
The biggest of the Uniflasy inserts – 25″ x 16″ = 400 square inches. Three finishes to choose from:
25×16 metal flat top with grease groove
Heavy-duty metal build, raised side walls, hollow side panels for airflow, groove design collects grease for less mess. Side handles for placement and removal. Best all-round pick if you want the biggest surface at the value price point.
25×16 nonstick cast iron with grease drain
Cast iron construction with nonstick coating for easier release. No seasoning required. Grease drain moves oil away from cooking area. Best for cooks who want cast iron heat retention but do not want to maintain a seasoned surface.
25×16 nano-ceramic nonstick
The most modern coating on the list. Nano-ceramic coating provides excellent food release and cleanup. Same 25×16 footprint. Also works with selected Weber Spirit 2025 Edition and Weber E-425 gas grills specifically.
Griddle vs Blackstone: what’s the difference?
| Format | Cook area | Cost | Storage footprint | Best for |
|---|---|---|---|---|
| Insert (17×13) | 221 sq in | ~$65 | Drawer | Occasional flat top cooks |
| Insert (25×16) | 400 sq in | ~$85 | Cabinet | Family + party cooks |
| Blackstone 28″ | 470 sq in | ~$350 | Patio permanent | Weekly flat top cook |
| Blackstone 36″ | 767 sq in | ~$500 | Patio permanent | Serious flat top cook |
Rule of thumb: if you cook flat top more than twice a week and have the patio space, buy the Blackstone. If you use it monthly or less, an insert is exactly the right tool.
The five things to check before you order
- Measure your grill. Measure inside grate to inside grate. Grill listings sometimes describe cooking area vs. total grill dimensions. Buy the size that fits your grill, not the biggest possible.
- Verify your grill model is compatible. Listings show compatibility lists. Not every grill accepts every insert – some are too curved, some have obstructions, some do not support the weight.
- Check burner support. Larger inserts (25×16) need adequate burner coverage underneath. Grills with widely-spaced burners can create hot spots and cool zones.
- Confirm heat rating. Manufacturer max temp ratings vary. If you want to sear at 700F, verify the specific product supports that.
- Know your grill\’s clearance. Some griddles are tall enough that closing the lid becomes a squeeze.
How to actually cook on a flat top insert
Preheat properly
Turn all burners to high, close the lid, wait 8-10 minutes. Test with a drop of water – it should sizzle and evaporate within 2 seconds. If it takes longer, wait longer.
Season if using bare cast iron
Bare cast iron griddles (not the nonstick nano-ceramic or porcelain enamel variants) need seasoning like any other cast iron cookware. A thin layer of high-smoke-point oil, wiped in, cooked at 400F for 30 minutes. Repeat 2-3 times before first food cook.
Use less oil than you think
A flat top does not need swimming oil like a regular pan. A thin coat of avocado oil, ghee, or beef tallow is enough for smash burgers. Excess oil pools at low points and burns.
Clean while warm, never scorching
After the last food comes off, let the griddle cool to warm (not hot), scrape food debris with a bench scraper, wipe with a wet cloth. Never pour water on a hot cast iron griddle – it will warp.
Recipes worth trying on your new flat top
- Smash burgers: two-ounce balls, pressed thin, salt and pepper, done in 2 minutes per side. Melt cheese in the last 30 seconds under a stainless bowl.
- Diner-style breakfast: bacon on one side, pancake batter on the other, eggs cooked in bacon fat. Timing everything to the same plate is the fun part.
- Teppanyaki fried rice: leftover rice, egg, soy, scallions, small shrimp or diced chicken. Higher heat than you would use indoors.
- Grilled cheese for a crowd: 4-6 sandwiches at once, buttered, weighted down with a foil-covered brick. Perfect for game day.
- Fajita veggies: sliced peppers and onions, medium heat, char just the edges. Move to the side, sear steak strips, combine.
Common flat top griddle mistakes to avoid
- Ignoring the manufacturer size chart. A too-large insert blocks airflow around burners and can damage the grill. A too-small one leaves gaps where grease drips onto burners.
- Cooking cold on a cold griddle. Flat top requires proper preheat – cold to cold means food sticks. Always preheat 8-10 minutes.
- Using metal utensils on nonstick coatings. Nano-ceramic and porcelain enamel coatings can be scratched. Use silicone, wood, or fish spatulas designed for nonstick.
- Trying to cook thick steaks. Flat top is not the right tool for a 2-inch ribeye. Use the regular grates for that. Flat top shines on thin, delicate, or small foods.
- Leaving grease on the surface between cooks. Even nonstick surfaces build up grease residue that carbonizes into hard spots. Wipe every cook.
Related PitPrimer guides
- Best Pellet Smoker 2026
- Best Meat Thermometer for BBQ 2026
- Best Traeger Accessories 2026 (coming soon)
- How to Smoke Brisket: First-Timer Guide (coming soon)
Bottom line
If your grill is a Weber Spirit, Char-Broil, Nexgrill, or similar mid-size gas grill and you cook flat top occasionally: buy the Uniflasy 17×13 metal insert for about $65. Fits in the drawer, drops on the grates in 60 seconds, handles weeknight burgers and weekend breakfast trivially.
If you have a full-size gas grill (Weber Genesis, Traeger, larger Nexgrill) and cook flat top for four or more: Uniflasy 25×16 flat top with grease groove or the nano-ceramic 25×16 for easier cleanup. Around $85-90.
If you want the best heat retention for serious searing: Uniflasy 23×16 porcelain enamel cast iron. Cast iron thermal mass makes a real difference on smash burgers and steak bites. Also usable on a 4-burner range stovetop for indoor use in winter.
Whatever you buy: measure your grill first, preheat properly before cooking, and clean while warm. A flat top insert is one of the highest-ROI backyard cooking upgrades you can make.
Please verify current prices and compatibility with your specific grill model before purchase.