How long does it take to bleach hair

By: | Last Updated: May 16, 2022

If you have decided to get your hair bleached but can’t decide whether to do it yourself or to get it done professionally, then maybe the factor of time will help you choose.

If you’re busy, you know that getting your hair bleached at a salon will take up a lot of your day. But doing it yourself at home may take less time but won’t guarantee you get great results. 

So how long does it take to fully bleach your hair?

Aside from the skill, there are other factors to consider to know how long it takes to bleach your hair. So if you want to know what they are, you’ll need to read more to find out.

How does bleach work?

How does bleach work

To figure out how long it takes to bleach your hair, you must first understand how it works.

To lighten your hair, you’ll need to mix bleach powder and hydrogen peroxide together. The hydrogen peroxide or developer will open up your hair cuticles so the bleach can enter your hair cortex.

Once the bleach is in, it will oxidize your hair melanin by turning the eumelanin colorless. Since the phaeomelanin will then be the only pigment that’s visible, your hair will turn yellow or red depending on the under pigments of your hair.

The processing time will differ depending on your base hair color and the strength of your developer. So if you want to know the difference, let’s break it down below.

How long does it take to bleach hair at the salon?

It’s always a good call to get your hair bleached professionally since hairstylists would know how to customize your treatment to get the best results.

Depending on the type of bleaching process, it can take about 10-30 minutes to lighten your hair. But it would take longer if you want to add in some highlights or a balayage since the colorist would need more time to do the proper techniques.

So overall, the entire session could last for 3 hours or more since you also have to factor in the time to apply, wash, and tone your hair.

But the perks of having a professional bleach your hair lowers the risk of damaging it since they would know the correct process to do for your hair type and condition.

How long does it take to bleach hair at home?

If you haven’t tried bleaching your hair at home, the process can take 20-45 minutes, depending on the length and color of your hair. 

Applying bleach to the back of your head can also be difficult, so you’ll need to refer to multiple mirrors if you don’t have anyone else to help you. Since you want to ensure you’ll get an even application, this method can add more time to your session.

But when you’re done applying, make sure the bleach won’t stay for more than 45 minutes on your hair since it’ll then start breaking down your hair fibers. So if you don’t want to see your hair falling off in clumps, you’ll need to rinse the bleach off immediately.

How long does it take to bleach brown hair?

Other factors that can determine how long a bleaching session will take are your natural hair color and how light you want it to be.

So if you want to bleach your hair at home, one bleaching session can take 45 minutes to 1 hour on dark brown hair. But to prevent any damage, it’s safer to wash the bleach off at 45 minutes.

If you have medium or light brown hair, you can rinse your strands before the 45-minute mark hits since it will take less time to process if your hair is lighter.

If you’re still not satisfied with how light your hair is, wait for at least 2 weeks to re-apply the bleach to let your hair recover.


How long does it take to bleach hair from black to blonde?

How long does it take to bleach hair from black to blonde

Black hair can be tricky to bleach since it will take several applications to get the pigments out.

So if you want to bleach your hair at home, one session can take 30-45 minutes, depending on how well your hair can handle the formula.

Since you’ll need to re-apply the bleach, it’s better to wait at least 2 weeks after so your hair has the chance to heal. If your hair feels gummy or brittle after any bleach application, don’t attempt to lighten it again until you get it back to a healthy state or risk damaging it further.

Until then, you can focus on taking care of your hair by applying deep conditioners and hydrating hair masks to make your hair stronger.

Hair developer strengths

The type of developer you’ll use with the bleach will also affect how long it will take to lighten your hair. Since you can use 20, 30, or 40 volume developers, let’s discuss how each can affect the time to process your hair.

How long to leave 20-volume bleach in hair?

A 20-volume developer can lift 1-2 levels of your hair color, so it’s recommended for when you want to go from dark blonde to platinum blonde.

So if you’re planning on using a 20-volume developer with your bleach, 30 minutes of processing time will do per session.

Using a 20-volume developer on dark brown hair will take more than 30 minutes to get to a platinum shade. Since going beyond that time frame will damage your hair, it’s better to use a more potent developer if you want to keep your hair intact.

How long to leave 30-volume bleach in hair?

A 30-volume developer is typically used when bleaching hair since it can lift 3-4 levels of your hair color in one application.

So depending on how light you want your hair to be, 15-30 minutes is enough to process your hair. Just make sure to check it every 10 minutes since the formula works faster than a 20-volume developer.

If you’re still not satisfied with how light your hair is after 30 minutes, you’ll still need to rinse the bleach off since it will then start frying your hair. 

You can still do another bleaching session after a couple of weeks if you want to lighten your hair further.

How long to leave 40-volume bleach in hair?

Using a 40-volume developer with bleach is not advisable if you haven’t tried lightening your own hair before. Since it has a very potent formula, the chances of damaging your hair will also be high.

Professional hairstylists use a 40-volume developer for lightening dark hair since it can lift 4-5 levels of your base color. A maximum of 20 minutes of processing time is enough since the formula can work fast to lighten your hair.

Leaving a 40-volume bleach formula on for too long can turn your hair brittle and your scalp irritated. So if you want to use it when lightening your hair, you’ll need to be cautious.

The do’s and don’ts of bleaching hair at home

The do’s and don'ts of bleaching hair at home

To cut back time on bleaching your hair at home, here’s a list of things you should and shouldn’t do to minimize the risk of damaging your hair.


  • Before soaking all of your hair with bleach, you’ll need to do a patch test 48 hours before to determine how well your hair takes it. It’s also to find out if you have any allergic reactions to the bleach.
  • Do section your hair into 4-6 parts to make it easier to apply the bleach evenly.
  • When brushing on bleach, start at the middle and ends of your hair before applying to your roots. Since the heat from your head will process your roots faster, making them lighter than the rest.
  • When developing, check your hair every 5-10 minutes to make sure you’re not overprocessing it.
  • When rinsing the bleach off, shampoo your hair to stop the lightener from processing it further.
  • If you need several applications, make sure to apply a hydrating hair mask between sessions so your hair won’t feel dry.


  • Avoid washing your hair the day before your bleaching session because your natural oils can protect your scalp from irritation.
  • Don’t wet your hair before applying the bleach since this will dilute the formula, thus, giving you weaker results.
  • Don’t let the bleach dry out when it’s still on your hair, as this will stop processing it. To prevent this, wrap your hair under a shower cap once you’re done applying.
  • Don’t attempt to lighten dark hair to a platinum blonde in 1 session since it would be too damaging for your hair.
  • Don’t skip the toner after bleaching your hair. This will eliminate brassy undertones to reveal a better, lighter shade. Use a toner that matches your hair color level to get the best results. 

CHECK OUT: How long does it take to dye hair? (At Home vs Salon)

Final thoughts

Bleaching your hair can be a significant change for you and your strands, so it’s essential not to hasten the process as this could lead to many mishaps.

So if you’re brave enough to bleach your own hair, it’s important to be patient and set a realistic expectation of how much time it takes to lighten your hair. Since it’s unhealthy to take black hair to a light blonde shade in 1 application, understand that it would take weeks before your hair can get into your dream shade.

But if you want to have a professional bleach your hair, you can call their salon to book a color consultation so you’ll know what to expect and how long it will take to process your hair.

Leave a Comment