How To Get Sweat Stains Out Of Hats (5 EASY Methods)

• How to find out what material your hat is made from
• How to get sweat stains out of hats
• How to dry a hat

Editor's Note: This post was originally posted in March 2022 and has been completely revamped and updated for accuracy and comprehensiveness in May 2026.

Have you got a hat that you don't wear anymore because it's stained or discoloured? We'll show you how to clean hats properly, without ruining their shape, colour or structure. 

You'll also learn the common cleaning mistakes that cause fading, shrinking, and long-term damage. 

Getting rid of annoying stains is such a pain, but removing sweat marks from hats is easier than you might think. Keep reading this article to find out how it's done. 

How to find out what material your hat is made from

Before you get started cleaning hats, this is the first thing you need to be cautious about. Different materials and constructions require different cleaning methods. 

These are the most common types:

• Baseball caps - these are usually made from cotton, polyester, or performance fabrics. These are the everyday curved-brim caps most people own. 
• Snapbacks - recognisable by their flat brim and adjustable snap closure. They often have a more rigid, structured front panel. 
• Trucker hats - feature foam or fabric fronts with breathable mesh backs. 
• Dad hats - softer, unstructured caps with a relaxed fit and a curved brim.
• Vintage hats - older hats may contain cardboard brims or delicate materials that can easily warp or shrink. 

If you're lucky, there might be a label in your hat with the fabric composition and washing instructions. If you can't find the label, check the manufacturer's website for more details or, in the absolute worst-case scenario, scour Google for more information about your hat. 

Read our guide about what laundry symbols mean for a helping hand.  

How to tell if your hat is structured or unstructured

This matters more than most people realise. 

• A structured hat keeps its shape even when you're not wearing it. The front panels feel firm or stiff. 
• An unstructured hat feels soft and flexible, and collapses when sat down. 

Structured hats are more likely to lose their shape if soaked or machine-washed improperly. 

Watch out for cardboard brims

Vintage hats may contain cardboard inside the brim instead of plastic. A quick way to check:

• Gently tap or flex the brim
• Plastic brims feel springy and flexible
• Cardboard brims feel stiff and can crease more easily

If you suspect cardboard, avoid soaking the hat completely. 

That's why treating every hat the same is one of the biggest mistakes people make. The safest cleaning method depends on the hat's material, age, and internal structure.

You will need

Don't worry, there are no fancy products here. You should have most of this at home.

• A sink or bowl
• Lukewarm water
• Mild detergent or gentle dish soap
• White vinegar
• A soft toothbrush or a clean cloth
• A towel
• Something to help hold shape while drying (like a bowl) 

Avoid bleach, strong chemicals, or anything abrasive. These can fade colours, weaken stitching, and shorten your hat's lifespan.  

How to clean hats

Now that you know what you're working with, let's get started with the best cleaning hacks for your hats. 

1. Begin by pre-treating sweat stains

If you've got a filthy hat, you'll want to pretreat the stains. Pretreating the sweat stains helps break down oils and sweat buildup before the full clean. 

If your hat has visible white salt marks from sweat, lightly spray the stained areas with a mixture of white vinegar and water. White vinegar helps dissolve the salt residue left behind by sweat. 

1. Spray the hat lightly, paying extra attention to areas with visible buildup or staining. 
2. Next, mix a small amount of detergent with water, then gently scrub the sweatband with a soft toothbrush. 
3. Start by testing a small hidden area of the hat, so the inside is a good place to start. This checks whether the colour will bleed or the fabric will react badly to water or detergent. 
4. If you see yellowing or dark stains, spend a little extra time here, but always be gentle.

Sweat contains salt and natural oils, and over time, this buildup can begin to affect the dyes in the fabric. That's why some hats develop fading or bleaching around the sweatband. 

Now that the hat is pre-treated, leave it to sit for around 5 minutes before washing. You'll notice it looks much better already. 

2. How to handwash a hat 

We've seen people use washing machines and even dishwashers to clean hats! While you can use these methods, both options can damage the fit and shape, so hand washing is the safest method. 

Here's what you need to do:

1. Fill a bowl or sink with lukewarm water and add around one tablespoon of laundry detergent or a small amount of washing-up liquid.
2. For soft, unstructured hats, the whole hat can be fully submerged. Gently move it around in the water to loosen dirt.
3. Leave the hat to soak for around 15-30 minutes so the detergent has time to break down dirt and sweat. You might notice the water becoming dirty. 

For structured hats such as snapbacks or fitted caps, full soaking should be avoided. Instead, use a cloth dipped in soapy water and clean section by section.

Use a soft toothbrush on dirtier areas, such as the brim edge, sweatband, and front logo. Light circular motions are enough.  You can go back over stained areas again with the toothbrush to help remove any remaining surface dirt. 

Please do not try this method if you have a leather, satin, silk, wool or felt hat. To ensure the dye does not wear off, only use this cleaning technique with colourfast hats. Never twist, wring or aggressively scrub the hat, or you could damage the shape.

TOP TIP: If the hat keeps floating to the surface, place a small glass container or bowl on top of the hat to help keep it submerged. 

3. Spot treatment

For any heavily stained hats or fragile materials, spot treatment is your go-to method. For example, we'd recommend this method for removing sweat stains from a leather hat. We wouldn't recommend this method for felt hats. Here's how it's done:

1. Firstly, check how bad the stain is. If it's going to be difficult to remove, it's best to pre-treat the stained areas using a mild stain cleaner. One thing you must take care not to do is expose your hat to chlorine or any other bleaching agent.
2. Take some mild, bleach-free detergent (or even your shampoo) in a container and mix it well with cold water. This will be your cleaning solution.
3. Next, take a clean cloth and dip it in the cleaning solution. Carefully rub the cloth on the stained hat until the marks start to lift. You can clean any other marks and the sweatband of your hat using the rest of the solution.
4. If you want to pick an alternative for the cleaning solution, we'd suggest white vinegar - it's an excellent stain remover. Following the steps above, take about 1 tbsp of white vinegar and use a clean cloth to dab each stain. Gently scrub until the stains are all gone. We've got more tips for using white vinegar for cleaning, so read next.
5. Once you're done removing sweat marks, you need to remove the excess soap solution. Take another cloth, dip it in cool water and then wipe it over the hat.
6. If you have a cotton hat, you can rinse it under a slow stream of water to remove the soap solution. However, if your hat is made of leather, it's best to use a moist sponge or cloth.
7. Finally, leave your hat to dry.

4. Putting your hat in the washing machine

We'd only ever suggest this as a last resort, if you're not too worried about the outcome. If you have a cotton or polyester hat, you could clean it in your washing machine. 

This method can be used for colourfast twill hats and baseball caps. Do not put your hat in a washing machine if the brim is made of cardboard.

1. Using a stain remover, pre-treat the hat. This will be helpful if your hat is quite heavily stained, as much of the staining can be removed by hand.
2. If you're planning to wash your hat along with other clothes, we'd suggest putting it in a garment bag to protect its shape.
3. Use a non-bleach dishwashing agent to prevent discolouration in dyed hats. There are some colour-safe bleaches available in the market these days, so you could also use those.
4. You're ready to turn the washing machine on! Set the temperature to cold, because hot water may damage your hat. You should also use a low spin setting.
5. Remove the hat from your washing machine or dishwasher once the cycle has finished. Use your hands to reshape the hat, then set it out to air-dry.

5. Dry cleaning

If nothing else works, or you're worried about ruining your hat, you always have the option to get it dry-cleaned. This is a good solution for cleaning felt hats, top hats, and fedoras. Take extra caution when checking what material your hat is made of.

All you need to do is make sure that the dry cleaners are experienced in cleaning hats. Cowboy hats, for example, need to be reblocked after dry cleaning to return to their original shape. A good dry cleaner should know these cleaning tips.

6. How do you get white stains out of black hats

To remove those annoying sweat marks from your favourite black hat, we'd recommend handwashing, spot treatment, or dry cleaning. Refresh your memory by checking out the steps above for each.

You'll need to take extra caution here so that you don't end up removing its colour. We suggest patch testing dyed hats to see how they hold up. You can also check the label, which will include instructions for washing your hat based on its material.

7. Rinse properly 

Once clean, rinse the hat with lukewarm water until all the soap is gone. Leftover detergent can leave residue, stiffness, or even streaky marks once it dries, so make sure it's fully rinsed. 

You'll know all the soap is gone once the water runs clear. 

For hats that can't be submerged, use a clean cloth dampened with water to blot the fabric. 

If the sweat stains were severe, there may still be some permanent fading or discolouration, but the hat should already look much cleaner.

How to dry a hat

Now that you've removed the stains from your hats, there's a thing or two you should know about getting them dry again:

• Take care not to leave your hat in direct sunlight while drying - it'll only cause more stains and colour fading.
• Never use a hairdryer or any other heating appliance to dry your hat, as this can cause damage. There are many uses for a hairdryer, but this isn't one of them.
• It might be tempting to put your hat through your washing machine or tumble dryer to dry, but this can fade its colour or ruin its shape. It's best to let it air dry.
• Roll up a hand towel and stuff it into the hat to keep it round and soak up any remaining water.

We hope this article on hat-cleaning hacks has answered all your queries and helped you bring your old, stained hats back to their former glory! Take care with your cleaning and let us know how you get on.

Next up, find out how to wash smelly gym clothes. We're sharing top tips from a national bikini champion!

Q&A

What kind of soap should I use to wash my hat in a dishwasher?

Your regular detergent would do in this case, but you must ensure that it does not contain bleach or citric acid. They may cause damage to the fabric.

Can I put my hat in the freezer?

Oddly enough, yes. Hats made of natural fibres like cotton and wool may give off a stinky smell due to bacteria from sweat and dirt. You can treat this by keeping your hat in the freezer overnight - your hat will be just fine. What a great freezer hack!

Can I iron a baseball cap?

Yes, you can. If your baseball cap is made of cotton or polyester, roll up a towel and stuff it into the crown of the hat to hold its shape, then steam-iron the wrinkles on a medium setting.

What does colourfast mean?

Colourfast means that the dye from your garment won't transfer. Take a clean, white cloth and dab it with lukewarm water. Try rubbing a tiny part of the fabric with this, preferably an area no one is likely to notice. If the dye transfers to the cloth, soaking the item in water will remove the colour. Otherwise, you can be assured that it's colourfast.

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Let us know in the comments below which type of hat you're trying to clean.