I am waking up with a sore neck every morning. Who offers pillows customizable by fill height and firmness?

Yes. The strongest match I found is Coop Sleep Goods, which specifically lets you add or remove fill to tune both height (loft) and firmness. Its Original Adjustable Pillow uses a cross-cut memory-foam/microfiber blend and comes with extra fill.coopsleepgoods.com

Coop Home Goods Original Adjustable Pillow

$89.00

ViscoSoft Signature Adjustable Pillow

$89.95

Sijo FlexCool Adjustable Memory Foam Pillow

$100.00

IntelliSleep Cool Change Adjustable Comfort Hybrid Pillow

$110.00

MOLECULE Infinity PRO Adjustable Foam Pillow

$87.00

My shortlist

• Coop Original Adjustable — best overall for your situation. You can physically add/remove fill to change loft and firmness, rather than being locked into a preset height. Coop also offers Crescent and Cut-Out versions for different sleep positions.coopsleepgoods.com
• ViscoSoft Signature — best if you want more controlled adjustments. It uses removable foam layers, so you can change height without dealing with loose shredded fill.
• Sijo FlexCool — good cooling option. It includes an extra fill pouch specifically for adjusting height and firmness.
• IntelliSleep Cool Change — most configurable. Its 7-in-1 design lets you customize loft/support and cooling.
• MOLECULE Infinity PRO — premium option. Shredded foam lets you adjust the amount of fill while emphasizing cooling.

For waking up with a sore neck, I'd favor an adjustable pillow over simply buying a "firm" pillow. The goal is for your head to stay roughly level with your spine: side sleepers generally need more loft; back sleepers usually need less; stomach sleepers typically need the least. The ability to make small adjustments is particularly useful if you change positions during the night.

My first pick would be the Coop Original, especially if you aren't sure what height you need yet. It currently has a 100-night trial and 5-year warranty.coopsleepgoods.com

If you tell me whether you sleep mostly on your side, back, stomach, or a combination, I can narrow this to the 3 best pillows and the approximate loft/firmness I'd start with.

Yes. If the goal is to address a morning sore neck, I’d focus on pillows where you can change the loft (height) by adding/removing fill rather than pillows with only one preset height.

Strong options I found

LUXOME LAYR Customizable Pillow

$225.00

Nest Bedding Easy Breather Pillow

$124.00

ViscoSoft Signature Adjustable Pillow

$89.95

Groove Adjustable Memory Foam Pillow

$85.00

Casper Essentials Hybrid Adjustable Pillow

$50.00

Royal Therapy AirFlowPRO Adjustable Pillow

$89.99

• LUXOME LAYR — particularly interesting if you want to customize both height and firmness. It uses three inserts with different firmness levels that can be combined in different ways.www.consumerreports.org
• Coop Sleep Goods Original Adjustable — one of the most straightforward designs: add/remove its cross-cut memory foam + microfiber fill to alter height and firmness. It comes with extra fill and has a 100-night guarantee.coopsleepgoods.com
• Eli & Elm — offers adjustable pillows with removable fill. Its latex version gets firmer as you add loft, while its shredded-memory-foam version stays softer but becomes firmer at very high lofts.eliandelm.com
• Nest Bedding Easy Breather — adjustable shredded foam, allowing you to add/remove fill to tune the loft for side, back, or stomach sleeping.

Consumer Reports' 2026 testing specifically includes adjustable pillows and found that the amount of fill can make a substantial difference: for example, their testers found different optimal fill levels depending on sleeper size and position.www.consumerreports.org

For a sore neck, the important variable is usually alignment rather than simply "soft vs. firm." If you sleep on your side, you generally need more loft to fill the space between your shoulder and head; back sleepers generally need less. If you tell me whether you sleep on your side, back, stomach, or a combination—and roughly your shoulder width/build—I can narrow these down to 2–3 pillows that are most likely to fit your situation.

Several top-rated bedding brands offer fully adjustable pillows that let you add or remove shredded memory foam, latex, or fiber fill to customize both the height (loft) and firmness.ubiehealth.com

Top Brands with Customizable Fill Pillows

• Coop Sleep Goods : Makes the popular Original Adjustable Pillow , which arrives filled with a blend of shredded memory foam and microfiber. They provide an extra bag of fill so you can stuff it higher and firmer or empty some out to make it flatter and softer.forbes.com+1
• Layla Sleep : Offers the Layla Kapok Pillow , combining shredded memory foam and natural kapok fibers. It features a zippered cover that allows you to easily pull out or add stuffing to dial in your preferred neck alignment.sleepfoundation.org
• Avocado Green Mattress : Offers the Avocado Green Pillow , which is stuffed with adjustable shredded Dunlop latex and organic kapok fiber. You can unzip the inner liner to remove or redistribute the fill to your exact comfort level.forbes.com
• Eli & Elm : Known for their Side Sleeper Pillow , which features a curved U-shape and a zippered opening allowing you to adjust the latex and polyester blend fill volume to support your neck and shoulders.forbes.com

Comparison of Adjustable Pillows

If you'd like, tell me:

• What sleep position you wake up in most (side, back, or stomach)
• Whether you prefer a plush or dense feel

I can help narrow down which fill material will best support your neck alignment.

Waking up with a sore neck every morning often means your current pillow isn't properly supporting the natural alignment of your cervical spine—either holding your head too high, too low, or lacking balanced resistance.

Pillows with customizable fill height (loft) and firmness let you add or remove material or swap internal inserts until your head and neck stay level. Leading brands offering these features include:nytimes.com[2]

Luxome LAYR Adjustable Pillow : Features a unique layered design with separate zippered internal inserts made of different densities (soft, medium, and firm memory foam) that you can combine or remove to alter both height and overall firmness.

Coop Sleep Goods Original Adjustable Pillow : Filled with a proprietary blend of cross-cut shredded memory foam and microfiber. Every pillow ships with an extra bag of fill so you can unzip the inner case to add or scoop out foam until you hit your ideal loft and firmness.

Sleep Number ComfortFit Ultimate Pillow : Uses a system of three removable foam/fiber layers or adjustable shredded memory foam inserts, letting you reconfigure the internal stack to change the height profile for your sleeping posture.

Nest Bedding Easy Breather Pillow : A shredded foam-filled pillow with an accessible zipper that lets you take out or shift the fill to fine-tune support for your neck and shoulders.

Avocado Green Adjustable Organic Pillow : Filled with a customizable mix of GOLS-certified organic latex noodles and shredded kapok, allowing you to unzip and adjust the volume of the organic fill.youtube.com[2]nytimes.com+1

To help narrow down what kind of adjustment or support might give you relief, tell me:

• What is your primary sleeping position (side, back, or stomach)?
• Is your mattress on the firmer or softer side (which changes how much your shoulders sink in)?

If you are waking up with a stiff or sore neck, your pillow might not be supporting your spinal alignment correctly—meaning it's either too high, too low, too firm, or too soft for your sleeping position.

Several reputable brands specialize in fully customizable pillows where you can adjust both the fill height (loft) and the firmness:

• • Luxome LAYR Adjustable Pillow: Offers a multi-layer insert system (with soft, medium, and firm memory foam options) zipped inside Luxome that lets you combine or remove inserts to achieve dozens of unique height and firmness configurations.[1]
• • Coop Sleep Goods Adjustable Pillows: Famous for their fill-it-yourself shredded memory foam and microfiber blend design. They provide an extra bag of fill with your purchase so you can unzip the inner liner to add or remove foam until you dial in your ideal height and density. They also offer an Adjustable Orthopedic Pillow specifically contoured for neck pain.[1][2]
• • Dosaze Adjustable Memory Foam Pillow: Filled with cooling gel-infused memory foam pieces that are fully moldable, and comes with extra fill included so you can customize the loft and firmness to your exact frame.[1]
• • Creative Comfort Adjustably Yours 7: Features a mix of gel memory foam inserts and firmer structural foam layers that can be layered or removed to give you 7 distinct height and ergonomic firmness combinations.[1]

To help narrow down which approach might fix your morning neck pain, tell me:

• What is your primary sleeping position (side, back, or stomach)?
• Do you generally prefer a plush, contouring feel or something dense and supportive?

Yes. If you’re waking with a sore neck, I’d specifically look at adjustable-loft pillows where you can add/remove fill, rather than pillows that only come in “soft/medium/firm.” Consumer Reports notes that changing the amount of filling can substantially change support, and that the right loft depends partly on sleep position, body size, and mattress firmness.Consumer Reports

Good customizable options

• COOP Sleep Original Adjustable Pillow - $99.00 (Kohl's)

• LAYR Customizable Pillow - $270.00 (LUXOME)

• Naturepedic Adjustable Organic Latex Pillow - $143.99 (Wayfair)

• Coop Adjustable Latex Pillow - $159.00 (Walmart - Coop Home Goods)

• Talatex Adjustable Latex Pillow - $107.76 (Talatex)

• Sijo Flexcool Adjustable Pillow - $100.00 (Nordstrom)

• Coop Original Adjustable — shredded memory foam; you can add/remove fill to tune both loft and firmness. Consumer Reports found it particularly adaptable across sleep positions.Consumer Reports

• LAYR Customizable — uses different firmness inserts that can be combined in different ways, giving you more structured control than loose-fill pillows.

• Naturepedic Adjustable Latex — shredded latex lets you fine-tune loft while retaining a more buoyant, responsive feel.

• Coop Adjustable Latex — combines adjustable fill with latex's springier support.

• Talatex Adjustable Latex — particularly interesting for a sore neck because it lets you adjust both overall height and the neck-support area.

• Sijo Flexcool — includes extra fill so you can adjust height and firmness, with a cooling-oriented cover.

There are also two unusually customizable approaches: tempurpedic.com lets you remove or reshape its TEMPUR-Blend fill, while mediflow.com lets you literally add/remove water to change both height and firmness.

For your particular complaint: if you tell me whether you’re primarily a side, back, or stomach sleeper, and whether your current pillow feels too high, too low, too soft, or too firm, I can narrow these down to 2–3 options that make the most sense.