We make six pillow fills, and people ask me all the time which one is best. It is the wrong question. There is no best fill, there is the fill that matches how you sleep and how you run at night. So here is the honest map, the one I would give a friend.
Start with feel, because it is what you notice the first night. Kapok and cotton are soft, kapok being the most down-like thing we make. Wool is a springy medium. Latex is buoyant and responsive, it pushes back. Buckwheat is firm and holds its shape. And the buckwool hybrid is a firm side and a soft side in one pillow, for people who cannot decide.
Then temperature, since half the people I talk to sleep hot. Buckwheat is the coolest, because air moves constantly between the hulls. Wool is the best at regulating, because it wicks moisture all night instead of quitting after twenty minutes like a gel pillow. Latex sleeps cool for a foam feel. Cotton and kapok are neutral. None of them trap heat the way closed-cell memory foam does.
Here is the part most brands blur, so I will be plain about it. Full-pillow GOTS organic certification, meaning the fill and the cover and the thread and the dye process are all certified, applies to cotton and wool only. On kapok, buckwheat, latex, and the buckwool hybrid, the organic cotton cover is GOTS certified and the fill is a clean natural material we describe for exactly what it is. The license is GOTS-10229, and you can look it up. The latex adds OEKO-TEX Class 1, the baby-grade tier, and FSC on the tree source.
Lifespan is the quiet advantage. Cotton holds for two to four years and re-lofts when you knead it back. Wool and buckwheat run three to five, and buckwheat you refresh by topping up the hulls. Latex lasts up to a decade. Kapok stays lofty for years with a daily fluff. All of them refill through the zipper, so you extend the pillow instead of buying a new one, which is the opposite of foam taking a permanent dent in months.
So, the shortcuts. Hot sleeper: wool or buckwheat. Neck pain: buckwheat, or buckwool if you want a soft side too. Want a soft, down-like feel: kapok. Replacing a flat foam pillow and want the simple durable answer: cotton. Want a bouncy, responsive lift: latex. Cotton, kapok, buckwheat, and latex are vegan; wool and buckwool are not; and if you have a latex allergy, choose cotton, kapok, or wool.
The full side-by-side, with the feel, temperature, certification, lifespan, and price for each, is here: compare all six natural pillow fills. Or take the two-minute quiz on the site and it will point you to the right one.
