How Long Do Mylar Balloons Last For?

Written By: Jennifer Fielding

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While balloons are a great option for livening up parties and celebrations, latex ones often feel like a waste, as they don’t tend to last long before they pop or sag. But how do the more expensive Mylar balloons fare? 

woman holding mylar balloons

Are Mylar balloons the better choice for all day events? What sort of lifespan should you expect from your balloon, and how can you extend it? 

Let’s take a look. 

How long do Mylar balloons last?

A typical Mylar balloon will stay inflated for up to 5 days, but it will vary depending on the ambient temperature and the quality and size of the balloon. Re-used Mylar balloons will be less effective over time. 

In the right conditions, and with a good quality balloon, you could see your balloon last a good two weeks before it starts to look crumpled and saggy. But a cheap Mylar balloon might barely last a day. 

How long do mini Mylar balloons last?

A smaller Mylar balloon won’t last as long as a regular-sized balloon. Mini Mylar balloons might last 2-3 days on average, maybe up to a week if they’re good quality. There’s less air needed to fill them, but that means as soon as air does escape, it’s more noticeable.

mini mylar balloons

How long do Mylar helium balloons last?

A Mylar balloon filled with helium will normally float for 3-5 days. Larger balloons may float for longer, though will start to sag and look partially deflated after a few days. 

helium mylar balloon

Mylar balloons don’t weigh much at all, so only a small amount of helium is needed to keep your balloon afloat.

Over time the helium will escape the balloon, or the pressure will drop, so the balloon won’t look as full as when first inflated. But the helium it has retained will keep it floating for a little while longer yet. 

How long do Mylar balloons stay inflated with air?

A Mylar balloon that’s filled with air should last for 3 to 5 days but it may start to sag and crumple a little earlier. You can top the balloon up at any time. 

Of course, a Mylar balloon filled with air isn’t going to float, so it’s not like it will start to sink as the air escapes. Instead, you’re just looking for signs that the balloon doesn’t look as full. 

But one of the benefits of Mylar balloons is that you can refill them to give them a little boost. 

Will Mylar balloons stay inflated overnight?

Any good quality Mylar balloon should stay inflated overnight with ease. They can last a few days if inflated properly, and kept in the right conditions. 

star shape mylar balloon

Mylar balloons don’t do well in the cold – more on that below – so if you live somewhere with chilly nights then your balloon might not look quite as full in the morning.

Mylar balloon quality

Mylar balloons are made from nylon coated with aluminum foil, with the balloon shape made by sticking different panels together. 

So if the balloon is a cheaper one, the build quality might not be great. That means air or helium might be able to slowly escape through the seams,or the valve could be weaker. 

deflated mylar balloon

If you want your Mylar balloon to last for a long time, make sure you buy a good quality one, ideally from a local party store you can trust. Otherwise, you might find it deflating sooner than you’d like. 

How to make Mylar balloons last longer

There are a few things you can do to make sure your Mylar balloon lasts as long as possible. 

Firstly and perhaps most obviously, keep them away from anything likely to pop them – so that’s sharp objects, anything with a pointed corner, or curious younger children who aren’t delicate. 

Mylar Balloon

Secondly, try to make sure the air temperature isn’t too cold or too hot. Changing air temperatures are often the main cause of balloons deflating prematurely. 

Do Mylar balloons deflate in heat? 

Mylar balloons are made from a heat-resistant material, but if they’re left somewhere hot, they can still deflate or pop.

Heat causes gas to expand, so whether your balloon is filled with air or helium, it could burst if it gets too hot.

Hot weather also speeds up molecule movements in the balloons, allowing the air to escape much faster. It’s recommended that you keep Mylar balloons away from hot places and direct sunlight. Still, Mylar balloons are better options for events on a hot day as they last longer than latex balloons. 

Do Mylar balloons deflate in the cold?

Mylar balloons filled with helium can deflate in cold temperatures. The helium gas condenses, meaning it doesn’t pack out the balloon, causing it to look deflated. 

None of the helium has escaped. In fact, if you move the balloon into a warmer space, it’ll look like it inflates itself. It could be a neat trick to entertain younger guests at the party.

A good tip is to make sure you’re inflating your Mylar balloons in a similar environment to where you’re placing them. The easiest way to do this is to inflate them as you hang them. That way, the air pressure inside the balloon is consistent with that outside the balloon. 

Refilling Mylar balloons

Even if you follow these tips for keeping your Mylar balloon inflated, they aren’t going to last forever. 

The good news is that they’re reusable, and so you can top them up with a little more air or helium to get them back to their best.

deflated mylar balloon

You shouldn’t do this if your helium-filled balloon deflates due to the cold. Adding more helium will reinflate it, but if the temperature changes it’ll be over-inflated and likely explode. 

Just follow the tips for how to inflate a Mylar balloon if you want to top one up. 

Which balloons last longer between Mylar and latex?

Mylar balloons last longer than latex balloons in pretty much any condition, including cold and warm temperatures and outdoors in the rain. Mylar balloons are a more premium balloon but they are more expensive, so many people still prefer latex if buying a lot.

Why do Mylar balloons last longer than latex?

Mylar balloons last longer than latex balloons because they are made from a different material. Mylar balloons are made from a synthetic nylon with aluminum coating, while latex balloons are made from, well, latex.

latex balloon with water

Latex is a porous rubber. It actually has loads of microscopic holes which all expand as the balloon is inflated. They’re small enough that the air mostly stays inside the balloon – otherwise it would never stay inflated – but over time the air particles will escape.

Mylar balloons are therefore much better at staying inflated, and at handling changing air pressure. But if you want to fill a room with balloons, it’ll likely be too expensive to do that with Mylar, so latex still has a place.

Final thoughts

If you’re only buying a few balloons to use as decorations, or as gifts, it’s much better to buy Mylar than latex. They last a lot longer, are more durable, and they don’t make that awful squeaking sound that latex does when it’s caught or rubbed against something.

The only thing to be aware of is the air temperature. Inflate the balloons where you want to hang them, if you can, otherwise, the changing pressure inside and outside the balloon might cause it to deteriorate faster.

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Jennifer Fielding

Jennifer Fielding is your go-to expert on all things inflatable, from pools to tents and beyond. A former owner of Deluxe Hot Tub Hire Ltd., she's experienced the ups and downs of inflatables firsthand. Nowadays, she writes practical guides on maintaining and enjoying inflatables. A mom of young enthusiasts, her family's favorite outing is the inflatable fun park!

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