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Tea & Herbs · Tea Basics

Does Green Tea Have Caffeine?

Green tea does contain caffeine, but usually less than coffee and often less than black tea. Learn what affects the amount and how to plan your cup.

Published
July 17, 2026

Yes, green tea has caffeine. It usually has less caffeine than coffee and often less than black tea, but it is not caffeine-free.

The amount depends on serving size, product and preparation. If caffeine affects your sleep, timing may matter more than the tea label.

Quick answer

Green tea is true tea made from Camellia sinensis, and true tea naturally contains caffeine. NCCIH also notes that green tea contains caffeine.

As a practical comparison, Mayo Clinic lists approximate 8-ounce examples where brewed green tea contains less caffeine than brewed black tea, and both contain less than brewed coffee. Those numbers are examples, not a promise about every mug.

If you want to plan tea around sleep, treat green tea as caffeinated. If you want a usually caffeine-free evening drink, look for an herbal infusion that is not made from true tea leaves, and still check the ingredient list.

How much caffeine is in green tea?

There is no single caffeine amount for all green tea.

Mayo Clinic’s caffeine table lists brewed green tea at about 28 mg caffeine per 8-ounce serving. FDA consumer guidance gives a broader example range for green or black tea of about 30 to 50 mg per 8-ounce serving.

Those values are useful starting points, not exact values for every cup. A small cup, a large mug, a bottled tea, a concentrated drink, a powdered tea or a strongly brewed loose-leaf tea may not match a general chart.

Green tea vs black tea vs coffee

In broad practical terms:

  • green tea usually has less caffeine than coffee;
  • green tea often has less caffeine than black tea;
  • black tea usually has less caffeine than brewed coffee; and
  • the exact amount can vary by product and preparation.

Mayo Clinic’s approximate examples list brewed coffee at about 96 mg per 8-ounce serving, brewed black tea at about 47 mg, and brewed green tea at about 28 mg. FDA gives brewed coffee as about 80 to 100 mg per 8 ounces and green or black tea as about 30 to 50 mg per 8 ounces.

Use those as comparison examples, not fixed rules. A large coffeehouse drink or a large strong tea can change the picture.

For a broader overview of tea categories, see green, black, white and oolong tea explained.

Why caffeine amounts vary

Caffeine in a cup can vary for ordinary reasons.

The final amount may depend on:

  • serving size;
  • how much tea is used;
  • leaf size and product form;
  • steeping time;
  • water temperature;
  • whether the tea is brewed from loose leaf, a bag, powder or concentrate; and
  • whether the product includes other caffeine-containing ingredients.

This is why two green teas can feel different. A delicate small cup is not the same as a large travel mug brewed strong. If caffeine matters, use the product label when available and keep your serving size consistent.

For preparation choices, the Tea Brewing Guide can help with tea type, water temperature and steeping time. For serving strength, see how much loose-leaf tea to use per cup.

Does decaf green tea still have caffeine?

Decaf does not always mean zero caffeine.

Decaffeinated products are made to reduce caffeine, but small amounts may remain. Mayo Clinic’s table includes decaffeinated examples with low but nonzero caffeine amounts.

If you need to avoid caffeine closely, check the package rather than assuming that “decaf” means caffeine-free. The exact amount can vary by product.

Does herbal tea have caffeine?

Herbal infusions are usually caffeine-free when they are not made from true tea leaves, but check blends and labels.

“Herbal tea” is often used casually for many plant-based drinks. A peppermint infusion made only from peppermint leaf is different from a blend that includes green tea, black tea, yerba mate, guarana, cacao or added caffeine.

If the product contains true tea, it contains caffeine. If it is a pure herbal infusion without caffeine-containing ingredients, it is usually chosen as a caffeine-free option. For the category difference, see true tea vs herbal infusions.

Green tea and bedtime

Green tea may matter close to bedtime, especially for people who are sensitive to caffeine.

EFSA notes that single doses of 100 mg caffeine may affect sleep duration and patterns in some adults, especially when consumed close to bedtime. FDA also notes that caffeine sensitivity and elimination vary from person to person.

Drake and colleagues studied 400 mg caffeine taken 0, 3 or 6 hours before bedtime and found disruptive effects on sleep in that study. That was 400 mg caffeine, not a normal cup of green tea, so it should not be exaggerated into “green tea ruins sleep for everyone.”

Still, the practical point is useful: if caffeine affects your sleep, timing matters. The article on how late is too late for coffee or tea explains why a 6-hour cutoff can be a reasonable starting point for substantial caffeine.

You can also use the Caffeine Cutoff Planner to turn your bedtime and sensitivity into a practical last-caffeine time.

How to choose your cup

Choose based on what you want the drink to do.

If you want a caffeinated daytime tea:

  • green tea can be a lighter-caffeine option than coffee for many people;
  • use a consistent serving size if caffeine matters;
  • follow the package or use a repeatable brewing method; and
  • adjust leaf amount and steeping time for taste.

If you want an evening drink:

  • consider whether green tea affects your sleep;
  • choose decaf only if a low-caffeine option is acceptable for you;
  • choose a caffeine-free herbal infusion when caffeine avoidance matters;
  • check blends for true tea, mate, guarana, cacao or added caffeine; and
  • move caffeinated tea earlier if sleep feels affected.

This is general information, not personal medical advice.

Practical takeaway

Green tea does have caffeine.

The useful summary:

  • green tea is caffeinated because it is true tea;
  • it usually has less caffeine than coffee;
  • it often has less caffeine than black tea;
  • the amount depends on serving size, product and preparation;
  • decaf does not always mean caffeine-free;
  • herbal infusions are usually caffeine-free when they are not made from true tea leaves, but labels matter; and
  • if caffeine affects your sleep, timing may matter more than the tea category.

Green tea is not “basically coffee,” but it is also not a caffeine-free bedtime drink for everyone.

Related tools and guides

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