Pros: These bags are affordable and easy-to-use, and you can pump directly into them.

Cons: You must purchase separate products to be able to pump into the bag, and they feel flimsier than other brands.

The Lansinoh bags are a favorite among parents, with nearly 90,000 positive reviews on Amazon. They’re one of the most affordable options, have a wide mouth that makes them easy to fill, hold up to 6 ounces of breast milk, and freeze very flat and evenly for convenient storage. They have space to write out the date and quantity, and pouring milk out of them is super simple. With an optional adapter (which is purchased separately) you can also pump directly into these bags. They are slightly thinner than other brands which means milk will thaw more quickly in these bags than other options.

Review: “Love these bags and I have tried just about every brand. These are the best! I haven’t had a single bag leak. They freeze super flat and even throughout the length of the bag. Other brands don’t freeze as evenly due to the construction of the bag. I can make a perfect block in a gallon bag with these bad boys, fitting 13 4-oz bags right side up in each ziplock.”

Pros: These freeze flat and evenly, are made from thick plastic, and are affordable and easy to thaw.

Cons: Plastic is a little thicker and stiffer than other options, which some customers might not prefer.

The Medela storage bags are similar to the Lansinoh bags: They’re nearly the same size, hold 6 ounces of breast milk, and lay flat and even when frozen. They have a double seal zipper and space at the top to write out the date and quantity. In testing, the Medela bags were a little harder to open up after thawing out because the plastic is a little less flexible. Some might find prefer this though, as it means the bags can stand upright. They’re another great and affordable option at about $16 for 100.

Review: “Love using these milk storage bags. Easy to write the dates on them with plenty of space available to fit anyone’s handwriting. Keeps the milk well and once sealed, I haven’t experienced any leaking issues.”

Pros: These are easy to use, have a double seal zipper, and freeze flat. Customers find them sturdy.

Cons: A little more expensive than comparable options, many users feel the measurements aren’t that accurate.

The Kindred Bravely breast milk storage bags are most similar to the Lansinoh option. They have a wide opening that is easy to fill and pour from, along with space at the top to write out the date and quantity. They freeze really flat and evenly for easy storage and there seems to be plenty of room for the milk to expand (these can hold up to 6 ounces). One note that some reviewers had is that the measurements on the bag don’t seem to be super accurate, so when using them, you may want to check the number on the bottle before you pour the breast milk in.

Review: “I have been through a lot of bags, and these are the best by far. They're sturdy, nice and thick, never leak even though I occasionally slightly abuse them. They're just all around the best ones I've found — no stress about how they are in the freezer or how I defrost them.”

Pros: A knob lid makes it easy to fill and pour these; they’re easy to store, hold a large quantity, are leak-proof, and reusable.

Cons: Not as affordable as single-use bags, bulkier than single-use options.

If you want to go the silicone reusable route, the Momcozy silicone bags were the best ones we tested. They hold up to 8 ounces of milk and feel sturdy and leak-proof, even when laying flat before freezing. The knob cap is very secure and makes it super simple to pour milk in and out. The handle on the side is convenient and it comes with tags to label. They seemed to be the most secure out of the three silicone bags tested thanks to the cap. They also have multiple uses, so when you’re done pumping, you can use these to store food or other items. They’re also easier to take on the go compared to single-use bags.

A few things to note about these (and silicone bags in general): They are bulkier than single-use bags and take up more space. The cost of these also adds up over time, especially if you are producing a lot of milk that needs to be frozen. But if you’re in the market for a reusable option for fridge storage and can travel well, this is the best storage.

Review: “I love this bags, I returned to work and this bags are so much easier to store my milk, easy to transfer to the bottle, great eco friendly solution to replace plastic bags. They don't spill and easy to clean. Just a tip: like they showed in the videos, when you add your milk slight press the side and you will see the actual volume.”

Pros: Easy to use and tear-off top makes for easy pouring.

Cons: Didn’t freeze as flat as some bags, holds 5 ounces compared to the usual 6, only comes with 25 bags in a package.

The Evenflo Feeding Advanced bags are easy to use, with a wide mouth that makes pouring milk in simple and an asymmetrical tear-off top that makes it just as easy to pour milk out. The label on top gives plenty of space to write out info, and they were easy to thaw. In testing, they didn’t freeze as flat as some other options, and they hold 5 ounces compared to the usual 6. They might also be more expensive over time, since each box comes with 25 bags compared to 50 or 100 for other similarly priced options. But if you don’t have the steadiest hand and are really concerned about spills, this might be the best option for you.

Review: “These bags are my favorite of all the brands I've used. They are durable and open up for a sturdy base allowing for stability when pouring milk in. The pour spout prevents drips, spills, and sloshing when pouring out.”

Pros: You can pump directly into these; they can be used as bottles with the right accessories; and the cap makes for easy sealing.

Cons: Extra accessories need to be purchased to use these as a bottle and the cap makes means they take up more space in the freezer. They’ll be more pricey over time.

Unlike many other storage bags, the Tommee Tippee Pump and Go bags have a leak-proof screw-on cap that makes it easy to pump directly into these or to use them as bottles. You do need to purchase a pump adapter for most pumps, and you need to purchase separate accessories to use them as a bottle, but that may be worth it in the end. The cap also makes it really simple to pour milk in and out, and it seemed to be pretty secure in testing. However, the cap also means these bags don’t lay as flat as the zipper-top options, so they will take up a little more space in the freezer (although they do stand up pretty well).

Review: “They are easy to store with how they stand up. The twist cap makes it leakproof. And the wide opening makes it easier to pour milk into. They are pricer, but so worth it.”

Pros: These hold 10 ounces of breast milk; have a wide mouth for easy filling and pouring; and are reusable, multi-purpose, portable, and dishwasher-safe.

Cons: These leaked when not upright before freezing, and the seal doesn’t seem as strong as some other options.

Motif Medical’s reusable silicone bags are another solid option for anyone looking for a sustainable storage bag. They hold up to 10 ounces of breast milk, so they’re great people producing a lot of milk. The wide mouth makes it easy to get milk in and out, and they stand upright really well. They’re definitely bulkier than single-use options, and in testing, they leaked immediately when they were not upright before freezing. However, they are dishwasher-safe, which makes for easy cleaning. They’re also cheaper than some other silicone options (although a pack does come with three instead of five), and they can be used for other things aside from breast milk later on.

Review: “These are great, my new go-to for storing milk. Environmentally friendly.”

Pros: These hold 7 ounces and have storage guidelines conveniently on the bag.

Cons: The label made it difficult to pour milk in and out, and they didn’t sit as flat as some other bags.

Milkies bags hold 7 ounces compared to the usual 6, so these can hold just a little bit more. (Which can make a difference over time!) The bags feature storage guidelines right on the front, which is convenient for new (sleep deprived) parents who may forget exactly how to handle breast milk. They’re pretty affordable and easy to use as well. The label on top is great for writing down important info, however, it did make it a little harder to pour milk in and out, since the mouth didn’t open quite as wide. In testing, these didn’t freeze as flat as some other options, but were still a space-saver.

Review: “I absolutely love these bags! I go through 50 a week between pumping and freezing and I can say I haven’t had any issues with them! Highly recommend these bags!”