6 Best Alternatives to the Sailnovo Car Roof Box 21 (2026)

How each alternative compares

KJTYSDM Rooftop Cargo Carrier Bag 51 in

The KJTYSDM Rooftop Cargo Carrier Bag offers a larger footprint at 51x39x17 inches compared to the original's 47x35x21 inches, giving you more length and width for bulky items. It weighs only 2.2 pounds, much lighter than the original's 11.3 pounds, making it easier to handle. The KJTYSDM includes a combination lock for added security, which the original lacks. However, its height is 17 inches, 4 inches shorter than the original, so tall items may not fit. It also uses roof mount straps rather than door hooks, so it requires a roof rack or crossbars. Choose this if you prioritize lightweight, lockable storage and have roof bars.

Sailnovo 15 cu ft Waterproof Roof Bag

The Sailnovo 15 cu ft Waterproof Roof Bag is a smaller, more affordable alternative at 15 cubic feet versus the original's 21 cubic feet. Its dimensions are 14.2x9.45x7.48 inches when stored, much more compact than the original's 47x35x21 inches, so it takes up less space when not in use. It is a soft shell design that mounts to the roof with straps, similar to the original, but it does not include door hooks for rackless cars. The original provides six door hooks for vehicles without roof racks. Pick this if you need a smaller, lighter bag for occasional trips and have a roof rack.

Sailnovo 20 cu ft Roof Bag

The Sailnovo 20 cu ft Roof Bag offers 20 cubic feet of capacity, just 1 cubic foot less than the original's 21 cubic feet. It is slightly heavier at 8.93 pounds versus the original's 11.3 pounds, making it a bit lighter to lift. Its stored dimensions are 11.8x7.48x14.4 inches, more compact than the original's storage bag size of 15x11x5 inches. The original includes six door hooks for rackless installation, while this model uses roof mount straps and likely requires crossbars. Choose this if you want nearly the same capacity in a lighter package and have roof bars.

MeeFar 15 cu ft Roof Bag

The MeeFar 15 cu ft Roof Bag provides 15 cubic feet of space, 6 cubic feet less than the original. Its dimensions are 44x34x17 inches, slightly shorter and wider than the original's 47x35x21 inches, with a lower height that may not fit tall gear. It weighs 100 kilograms according to the data, which is likely a listing error; the original is 11.3 pounds. The MeeFar claims 100% waterproof protection, matching the original's weatherproof rating. It uses roof mount straps rather than door hooks, so it requires a roof rack. Pick this if you need a waterproof bag for smaller loads and have crossbars.

The FIVKLEMNZ 30 Cubic Feet Roof Bag offers 30 cubic feet of capacity, 9 cubic feet more than the original's 21 cubic feet. Its dimensions are 60x60x20 inches, significantly larger in length and width than the original's 47x35x21 inches, so it can carry more bulky items. It weighs 12 pounds, slightly heavier than the original's 11.3 pounds. The FIVKLEMNZ uses roof mount straps, not door hooks, so it requires a roof rack. The original works with or without racks thanks to its six door hooks. Choose this if you need maximum soft-bag capacity and have a roof rack.

Sailnovo 21 cu ft Soft Roof Bag

The Sailnovo 21 cu ft Soft Roof Bag matches the original's 21 cubic feet capacity exactly. It is a soft shell design that mounts with tie-down straps, while the original uses six door hooks and eight adjustable straps for rackless installation. This model weighs 8.16 pounds, lighter than the original's 11.3 pounds. Its stored dimensions are 9.84x7.09x13.8 inches, similar to the original's storage bag. The original is weatherproof with a waterproof zip and double-reinforced seams; this model is also waterproof. Pick this if you want the same capacity in a lighter bag and have a roof rack.

Quick picks

Our 7 picks

1 Best overall

Sailnovo 21 cu ft Foldable Roof Box

Best for: drivers needing a foldable, weatherproof roof bag

Capacity

21 cubic foot

Water Resistance

Weatherproof

Installation

6 door hooks and 8 adjustable straps

Vehicle Compatibility

Fits most cars with or without roof rack

Dimensions

47 x 35 x 21 inches

Weight

11.3 pounds

View on Amazon: Sailnovo 21 cu ft Foldable Roof Box

This is a soft-sided cargo bag that provides 21 cubic feet of storage (47 x 35 x 21 inches). It installs with 6 door hooks and 8 adjustable straps, fitting cars with or without roof racks. A non-slip mat and weatherproof construction help protect your gear. It folds into a compact storage bag for easy transport.

Pros

• 21 cubic foot capacity fits 6-8 suitcases plus camping gear
• Includes 6 door hooks and 8 adjustable straps for secure mounting
• Weatherproof with waterproof zipper and reinforced seams
• Folds into a 15 x 11 x 5 inch storage bag for portability
• Anti-slip mat reduces roof scratches and wind noise

Cons

• Soft-sided bag offers less protection than a hard shell box
• No internal frame or rigid structure to maintain shape
• Installation requires hooking into door frames, which may not suit all vehicles

Good fit if

• You need extra cargo space for road trips or camping
• You have a car with or without roof racks and want a universal fit
• You prefer a lightweight, foldable storage solution

Skip if

• You need a hard-shell roof box for heavy or fragile items
• You want a permanently mounted roof box that doesn't use door hooks
• You require a larger capacity than 21 cubic feet

Verdict: Sailnovo 21 Cubic Feet Foldable Roof Box is a practical soft-sided cargo bag for drivers who need temporary, weather-resistant storage and can work with door hooks.

2 Also great

KJTYSDM Rooftop Cargo Carrier Bag 51 in

Best for: drivers needing a large, rack-free roof bag with a lock

Shell Type

Soft shell

Water Resistance

Weather resistant

Security

Combination lock

Installation

Straps, buckles, door hooks

Dimensions

51 x 39 x 17 in

Recommended Use

Luggage, blankets, tents, sleeping bags

View on Amazon: KJTYSDM Rooftop Cargo Carrier Bag 51 in

This KJTYSDM soft shell roof bag measures 51 x 39 x 17 inches and holds 21 cubic feet of gear. It installs on vehicles with or without roof racks using straps, buckles, and door hooks. A combination lock is included. It suits drivers who want a weather resistant, foldable cargo bag for luggage, tents, or sleeping bags.

Pros

• Works on cars with or without roof racks using included door hooks
• Large capacity: 51 x 39 x 17 inches for bulky gear
• Comes with a combination lock for security
• Weather resistant coated fabric resists rain and dust
• Folds into included storage bag when not in use

Cons

• Soft shell offers less protection than a hard shell box
• No internal frame or rigid structure to hold shape
• Only one color option available

Good fit if

• You need a roof bag that fits vehicles without side rails or cross bars
• You want a large, soft cargo carrier that folds away for storage
• You prefer a built-in combination lock over a separate padlock

Skip if

• You want a hard shell roof box for maximum security and aerodynamics
• You need a roof bag smaller than 21 cubic feet for a compact vehicle

Verdict: KJTYSDM Rooftop Cargo Carrier Bag 51x39x17 in is a solid soft shell alternative with wide vehicle compatibility, a combination lock, and foldable storage.

3 Best budget

Sailnovo 15 cu ft Waterproof Roof Bag

Best for: budget-conscious drivers needing a versatile soft roof bag

Capacity

15 cubic feet/430 L

Shell Type

Soft Shell

Water Resistance

Waterproof

Dimensions

14.2 x 9.45 x 7.48 in

Vehicle Type

Car

Mount Type

Roof Mount

View on Amazon: Sailnovo 15 cu ft Waterproof Roof Bag

This is a 15-cubic-foot soft-shell roof bag from Sailnovo. It measures 41 by 35 by 17 inches and holds 3 to 5 medium suitcases. The bag is made of 1000D material with waterproof zippers and double seams. It fits cars with or without roof racks and includes 6 tie-down straps, 4 door hook straps, and a protective mat.

Pros

• 15 cubic feet capacity holds 3-5 medium suitcases
• Waterproof 1000D material with double-seam construction
• Includes 6 heavy-duty tie-down straps and 4 door hook straps
• Fits cars with or without roof racks, including bare roofs
• Foldable for compact storage when not in use

Cons

• Smaller capacity than other options on this list (15 cu ft vs 21 cu ft)
• Soft shell offers less security than a hard-shell box
• No built-in lock; relies on straps and door hooks for security

Good fit if

• You need a budget-friendly roof cargo solution for occasional trips
• You have a car without roof rails or crossbars
• You want a lightweight, foldable bag that stores easily

Skip if

• You need more than 15 cubic feet of storage capacity
• You prefer a hard-shell box with a locking mechanism
• You carry valuable items that require a secure, rigid container

Verdict: Sailnovo 15 cu ft Soft Roof Bag is a practical, affordable soft-shell carrier for drivers who need occasional extra cargo space and want a bag that fits almost any car, including those without roof racks.

4 Best premium

Sailnovo 20 cu ft Roof Bag

Best for: large family road trips with or without roof bars

Capacity

20 cu ft / 580L

Shell Type

1000D waterproof PVC

Water Resistance

Waterproof

Installation

Straps, door hooks, non-slip mat

Vehicle Compatibility

With or without roof bars

Dimensions

51 x 39 x 17 in

View on Amazon: Sailnovo 20 cu ft Roof Bag

This is a 20 cubic foot (580L) soft roof bag from Sailnovo, made of three-layer 1000D waterproof PVC. It measures 51 x 39 x 17 inches and weighs 8.93 pounds. It installs on vehicles with or without roof bars using straps, door hooks, and a non-slip mat. It suits families needing a large, foldable cargo carrier for road trips.

Pros

• 20 cu ft capacity holds luggage for 5-8 people
• Three-layer 1000D waterproof PVC with extended rain curtain
• Includes 6 reinforced straps, 6 door hooks, and non-slip mat
• Folds into storage bag when not in use
• Works on vehicles with or without roof bars

Cons

• Soft shell offers less security than a hard roof box
• No locking mechanism listed; relies on straps and hooks
• May require extra dry bags in extreme weather per manufacturer

Good fit if

• You need a large, waterproof soft roof bag for family trips
• You want a carrier that works on vehicles without roof bars
• You prefer a foldable, storable option to save space and fuel

Skip if

• You want a hard-shell roof box for maximum security
• You need a carrier with a locking system
• You prefer a smaller, lighter bag for occasional use

Verdict: Sailnovo 20 cu ft Roof Bag is a practical, large-capacity soft roof bag for families who need waterproof storage and flexible installation on most vehicles.

5 Best 15 cubic feet

MeeFar 15 cu ft Roof Bag

Best for: compact waterproof cargo on any vehicle

Capacity

15 cubic feet

Shell Type

700D PVC tarpaulin

Water Resistance

100% waterproof

Security

combination lock

Installation

quickly and easily installed in minutes

Dimensions

44" L x 34" W x 17" H

View on Amazon: MeeFar 15 cu ft Roof Bag

The MeeFar 15 Cubic Feet Roof Bag is a soft-shell cargo carrier made from 700D PVC tarpaulin that is 100% waterproof. It measures 44 inches long, 34 inches wide, and 17 inches high, providing 15 cubic feet of storage. It includes an anti-slip mat, security hooks, and a combination lock. This bag works with any car or SUV, with or without a roof rack, and folds into a storage box when not in use.

Pros

• 100% waterproof 700D PVC tarpaulin construction
• Comes with a combination lock for zipper security
• Includes anti-slip mat and 6 security hooks
• Folds into included storage box when not in use
• Works with any car or SUV, with or without a roof rack

Cons

• Soft shell offers less protection than a hard roof box
• Only 15 cubic feet capacity, smaller than some alternatives on this list
• No integrated lighting or remote lock listed

Good fit if

• You need a waterproof roof bag that can be stored compactly when not in use
• You have a car without a roof rack and need a universal fit
• You want a budget-friendly soft cargo carrier with included security features

Skip if

• You need more than 15 cubic feet of cargo capacity
• You prefer a hard-shell roof box for maximum protection and aerodynamics
• You want a bag with a larger height dimension than 17 inches

Verdict: MeeFar 15 Cubic Feet Roof Bag is a practical soft-shell cargo carrier that offers 100% waterproof protection and easy storage, making it a solid choice for smaller loads.

6 Best 21 cubic feet

Sailnovo 21 cu ft Soft Roof Bag

Best for: large waterproof soft-shell roof storage

Capacity

21 cubic feet

Shell Type

Soft Shell

Water Resistance

Waterproof

Installation

Tie-Down Strap

Dimensions

9.84 x 7.09 x 13.8 in

Vehicle Type

Car

View on Amazon: Sailnovo 21 cu ft Soft Roof Bag

This is a soft-shell rooftop cargo carrier from Sailnovo with 21 cubic feet of capacity. It mounts to your car with tie-down straps and is listed as waterproof. The bag measures 9.84 by 7.09 by 13.8 inches and weighs 8.16 pounds. It suits you if you want a large, collapsible roof bag for a car without a permanent hard box.

Pros

• 21 cubic feet capacity
• Waterproof soft shell
• Tie-down strap installation
• Weighs 8.16 pounds

Cons

• Soft shell offers less rigidity than a hard box
• Dimensions listed as 9.84 x 7.09 x 13.8 in may be folded or compressed
• No hard-shell protection for fragile items

Good fit if

• You need 21 cubic feet of cargo space on your roof
• You want a waterproof soft carrier that installs with tie-down straps
• You prefer a lightweight roof bag over a hard shell

Skip if

• You need a hard-shell carrier for maximum security
• Your car lacks roof mounting points for tie-down straps
• You carry fragile items that need rigid protection

Verdict: Sailnovo 21 Cubic Feet Roof Bag is a straightforward soft-shell cargo carrier that delivers the full 21 cubic feet of space with waterproof materials and tie-down mounting, best for budget-conscious roof bag shoppers.

7 Also great

RoofPax 19 cu ft Polyester Roof Bag

Best for: vehicles without roof racks needing weather-resistant storage

Capacity

19 Cubic feet

Shell Type

polyester

Water Resistance

100% waterproof

Installation

door hook straps, 10 straps

Vehicle Compatibility

fits cars with or without roof rack

Dimensions

47.2 x 35.4 x 19.8 in

View on Amazon: RoofPax 19 cu ft Polyester Roof Bag

The RoofPax 19 Cu Ft Polyester Cargo Bag provides 19 cubic feet of storage space directly on your vehicle roof. It measures 47.2 by 35.4 by 19.8 inches and weighs 12.4 pounds. Made from waterproof polyester rather than PVC, it includes four door hooks and ten straps to mount on bare roofs or existing crossbars. This bag suits you if you want flexible mounting hardware and dedicated zipper coverage.

Pros

• Constructed from waterproof polyester with dual zippers and water-repellent coating
• Includes 4 door hook straps for vehicles without roof racks or crossbars
• Comes with 10 connection straps and an included storage bag
• Features a lifetime zipper warranty and a 5-year fabric durability warranty

Cons

• 19 cubic feet capacity provides less volume than 21 cubic foot alternatives
• No protective roof mat listed in the included package contents

Good fit if

• You drive a vehicle without crossbars or side rails and need door hook mounting
• You prefer polyester fabric over standard PVC construction
• You want documented warranty coverage for the zippers and fabric

Skip if

• You need a full 21 cubic feet or larger roof carrier
• You require an all-in-one bundle that includes a roof protection pad

Verdict: RoofPax 19 Cu Ft Polyester Cargo Bag fits road trippers who need a rack-free mounting setup supported by specific zipper and fabric warranties.

Specifications side by side

Frequently asked questions

See also

• best subwoofers for cars