20 Vol vs 30 Vol Developer: Which One to Use?

Developer is one of the most used and least discussed products in any colour bar. It is easy to grab whatever bottle is closest, but the strength you choose changes how much lift you get, how well grey is covered, how fast the colour processes and how much stress the hair takes. Getting 20 vol vs 30 vol developer right is one of the simplest ways to improve colour results.

This guide is for colourists, apprentices and informed home users who want to understand what each strength does. It is general information only. Always follow the colour or lightener manufacturer’s mixing instructions, as every system is formulated to work with specific developers.

What developer actually does

Developer, also called peroxide or oxidant, is a cream or liquid containing hydrogen peroxide. When mixed with permanent colour or lightener, it helps open the cuticle and lift natural pigment so the colour molecules can develop inside the hair.

The strength is shown in two ways, as a volume and as a percentage:

10 vol = 3 percent
20 vol = 6 percent
30 vol = 9 percent
40 vol = 12 percent

Some brands also make very low strength developers, around 1.8 to 1.9 percent, for demi permanent colour and toning.

20 vol vs 30 vol developer: the key differences

20 vol (6 percent)

20 vol is often described as the workhorse of the colour bar. In many permanent colour systems it is the standard choice for:

Grey coverage
Colouring on level or darker
Small amounts of lift, commonly around one to two levels, depending on the brand

Because it is gentler than 30 vol, it is a common choice when the hair is fine, fragile or previously coloured, and when the colour is being applied at the scalp.

30 vol (9 percent)

30 vol gives more lift. In many permanent colour systems it is used for:

Lifting more levels than 20 vol allows, commonly around two to three levels
High lift colour, where the brand recommends it
Lightening resistant or very dark natural hair

The trade off is more potential for dryness, damage and scalp sensitivity, so it needs more care with application, timing and hair condition.

Quick comparison

Lift: 20 vol gives less lift, 30 vol gives more.
Grey coverage: 20 vol is the usual choice in most systems.
Gentleness: 20 vol is gentler on hair and scalp.
Processing: 30 vol can act faster and more aggressively, so watch timing closely.

Is 30 vol developer damaging?

Any developer causes some change to the hair, because that is how lifting works. Higher strengths lift more and can cause more damage, especially on hair that is already lightened, fine or fragile. 30 vol is not automatically harmful, but it should be used for a reason, not out of habit. Ask yourself:

Do I need the extra lift, or would 20 vol achieve the target?
Is the hair in good enough condition to handle it?
Am I applying it near the scalp, where heat speeds processing and sensitivity is higher?

When in doubt, do a strand test.

What developer to use with bleach

Lightener is where developer strength matters most. Many colourists work with lower strengths, often 20 vol, for on scalp lightening and choose stronger developer only when the hair and the technique call for it. Higher volumes lift faster but are harsher, and lifting slowly with a lower volume is often kinder to the hair.

Key points:

Follow the lightener manufacturer’s recommended developer strengths and mixing ratios.
Avoid high strength developer on the scalp unless the product is specifically formulated for it.
Monitor processing closely and never leave lightener unattended.

Bond builder for bleach

Searches for bond builder for bleach and bond builder to add to bleach are common, and for good reason. Bond builders are added to lightener, or used as a step after it, to help protect the hair’s internal structure during lightening. They do not stop lightener from working, but they can help the hair come out stronger. Professional systems such as Cree Multiplex and Nak Structure Complex are two examples sold through salon wholesalers. Always follow the brand’s instructions for how much to add, as adding a bond builder can change processing time.

What developer to use with toner

Toners are usually designed to deposit tone rather than lift, so they are generally paired with a low strength developer. Depending on the brand, that might be a dedicated activator, a 1.8 to 1.9 percent developer, or 10 vol. Some toners are pre mixed or come as leave in products that need no developer at all.

Using a stronger developer than recommended with toner can add unwanted lift and make results harder to control, so stick to the manufacturer’s pairing.

What developer to use for dark hair

Dark hair contains more pigment, so the right developer depends on the goal:

Covering grey on dark hair, or going darker: 20 vol is the usual choice in many systems.
Lifting dark hair a few levels with permanent colour: 30 vol may be recommended by the manufacturer.
Lightening dark hair significantly: lightener with an appropriate developer, often in several gentle sessions rather than one aggressive one.

Dark hair also tends to reveal warm undertones as it lifts, which is why toning is such an important follow up step.

Mixing and safety tips

Measure accurately. Use a scale or measuring cup and follow the stated ratio. Too much or too little developer changes the result.
Mix fresh. Mixed colour and lightener should be used straight away and never stored.
Check the hair first. Previously lightened or damaged hair may need a gentler approach.
Do the allergy alert test. Follow the colour manufacturer’s instructions for skin testing before permanent colour.
Wear gloves and work in a well ventilated area.
Store developer properly. Keep it tightly closed, out of heat and direct sunlight.

Stocking developer in your salon

Most salons carry at least 20 vol and 30 vol, with 10 vol and 40 vol available for specific services. If you use more than one colour brand, keep each brand’s developers grouped with its colour to avoid mix ups.

You can browse developers from several brands in the peroxides and developers range. For example, Cree Creme Developer 20 vol 6 percent is listed at $19.95 for a litre at the time of writing. Colour is available in the hair colours range, and if you lighten with BLONDME, see the BLONDME range. Both the Wetherill Park and Beresfield stores offer Click and Collect, which is handy when you run low mid week.

Colourists across Western Sydney can compare developer strengths in store at Elite Hair Supplier in Wetherill Park, or order online for Click and Collect.

FAQ

What is the difference between 20 vol and 30 vol developer?

20 vol is 6 percent hydrogen peroxide and is commonly used for grey coverage and up to about one to two levels of lift. 30 vol is 9 percent and gives more lift, commonly around two to three levels, with more potential for damage. Always check the brand’s guide.

Can I use 30 vol developer instead of 20 vol?

You can, but you will get more lift and potentially warmer, less predictable results and more stress on the hair. Only swap if the manufacturer and your target result support it.

What volume developer should I use with toner?

Most toners use a low strength developer or a dedicated activator, often around 1.8 to 1.9 percent or 10 vol depending on the brand. Follow the toner manufacturer’s instructions.

Is 20 vol developer good for bleach?

Many colourists use 20 vol for lightening, especially on the scalp, because it lifts more gently. Follow the lightener manufacturer’s recommended strengths.