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Psychological Encyclopedia

Black Tea Caffeine vs Coffee: Which Has More and Why Serving Size Matters

Sep 29
20 min read

Author: Ukrainian Psychological Hub · Published: September 29, 2026 · Editorial Policy


Coffee usually has more caffeine than black tea when you compare the same volume of brewed beverage. But “a cup of tea” and “a cup of coffee” are not standardized doses. A large black tea can deliver as much caffeine as a smaller coffee, while a weak tea and a strong coffee can be separated by several-fold. Serving size is therefore part of the caffeine comparison, not a detail to add afterward.



This article owns the narrow question “black tea caffeine vs coffee”: how much caffeine each drink usually contains, why the answer changes with volume and preparation, how to compare concentration with total dose, and what those differences can mean for alertness, sleep, and subjective stimulation. For the broader comparison of taste, routine, sensory experience, and daily use, see Black Tea vs Coffee: Caffeine, Alertness, Taste, and Daily Routine.


Quick Answer: Coffee Usually Has More Caffeine Than Black Tea


At equal serving sizes, brewed coffee usually contains more caffeine than brewed black tea.


Three authoritative reference points tell the same general story:


  • Mayo Clinic: 8 fl oz / 237 mL brewed black tea — 48 mg; 8 fl oz / 237 mL brewed coffee — 96 mg.

  • U.S. FDA: 12 fl oz / 355 mL black tea — 71 mg; 12 fl oz / 355 mL regular brewed nonspecialty coffee — 113–247 mg.

  • European Food Safety Authority: an approximate 220 mL cup of black tea — 50 mg; an approximate 200 mL cup of filter coffee — 90 mg.


The European Food Safety Authority explicitly notes that both caffeine content and portion size vary. That sentence is the key to reading every caffeine comparison correctly.


If the volume is equal, coffee is usually the higher-caffeine drink. If the real-world serving volumes are different, the total caffeine dose can be much closer.


Black Tea vs Coffee Caffeine by Serving Size


The simplest useful comparison is to hold volume constant.


8 ounces: about 48 mg in black tea vs 96 mg in brewed coffee


The Mayo Clinic reference table gives 48 mg for an 8-ounce brewed black tea and 96 mg for an 8-ounce brewed coffee. On that reference, coffee contains about twice as much caffeine per equal-volume serving.


This does not mean every coffee has exactly double the caffeine of every black tea. It means that, at these representative values, the concentration of caffeine in the brewed coffee is about twice that of the brewed black tea.


12 ounces: about 71 mg in black tea vs 113–247 mg in brewed coffee


The FDA uses a larger reference serving. For 12 fluid ounces, it lists 71 mg for black tea and 113–247 mg for regular brewed nonspecialty coffee.


That coffee range is wide. A 12-ounce coffee at the lower end is still above the FDA’s typical 12-ounce black-tea value, while the upper end contains several times as much.


The practical lesson is stronger than any single ratio: coffee usually wins the equal-volume comparison, but coffee itself is highly variable.


16 ounces: serving size can erase the neat “tea has half as much” rule


If the Mayo Clinic’s 8-ounce reference concentrations are scaled purely for illustration, a 16-ounce black tea would contain about 96 mg, while an 8-ounce brewed coffee would contain about 96 mg.


That is arithmetic, not a laboratory claim about a specific café drink. It assumes the beverage concentration stays the same as volume increases. Real drinks may be brewed with more or less tea leaf, more or less coffee, extra water, ice, concentrates, or multiple tea bags.


Still, the example shows why serving size matters. “Black tea has less caffeine than coffee” can be true per ounce while a large black tea and a small coffee deliver similar total doses.


Concentration and Total Caffeine Are Different Questions


Two numbers matter in any caffeine comparison:


  • concentration: how much caffeine is present per unit of liquid, such as mg per ounce or mg per 100 mL;

  • total dose: how much caffeine is in the entire serving you actually drink.


Coffee is usually more concentrated in caffeine than black tea. But total dose equals concentration multiplied by serving volume.


A 20-ounce drink does not become “low caffeine” because its concentration is moderate. Conversely, a one-ounce espresso can be extremely concentrated without containing as much total caffeine as a much larger brewed coffee.


This distinction is the reason “Which has more caffeine?” needs a unit attached to it: more per ounce, more per 100 mL, or more in the entire drink?


For a broader guide to coffee-side variation by bean, roast, brewing method, and serving volume, see How Much Caffeine Is in Coffee? Bean, Roast, Brew, Serving Size, and Why Effects Vary.


Why “One Cup” Is a Bad Caffeine Unit


In nutrition writing, a cup may mean 8 fluid ounces. In a home kitchen, a mug may hold 10, 12, 14, 16, or more ounces. In a café, “small,” “medium,” and “large” are commercial serving sizes, not scientific units.


The word cup therefore hides two different sources of uncertainty: the beverage can have a different caffeine concentration, and the container can have a different volume.


A comparison becomes much more useful when it says:


  • what drink was measured;

  • what volume was served;

  • how the drink was prepared;

  • whether the caffeine value is measured, manufacturer-reported, database-derived, or a general estimate.


This is why the FDA, EFSA, and Mayo Clinic values should be treated as reference points. They are better than a floating claim such as “tea has 40 mg and coffee has 100 mg,” because they attach caffeine to an explicit serving size.


Can Black Tea Ever Have More Caffeine Than Coffee?


Yes, in a real serving it can, although coffee usually contains more caffeine at equal volume.


There are two main ways this can happen.


First, the black-tea serving can simply be much larger. A large mug of black tea may contain more total caffeine than a small or diluted coffee.


Second, both beverages vary in concentration. A strong black tea made with more leaf, more tea bags, hotter water, or a longer steep can contain more caffeine than a weak coffee prepared with a low coffee-to-water ratio.


Analytical research has repeatedly shown that tea is not a fixed-caffeine product. Chin and colleagues measured 20 commercial teas and found 14–61 mg per 6- or 8-ounce serving across white, green, and black teas, with steep time affecting caffeine concentration. That range overlaps the caffeine content of some lower-caffeine coffee servings.


So the correct answer is not “coffee always has more.” It is: coffee usually has more at equal volume, while serving size and preparation can produce overlap.


Why Black Tea Caffeine Varies


Black tea is a brewed plant product, not a standardized caffeine solution. The caffeine in the finished drink depends on the dry leaf and on extraction into water.


For the detailed black-tea-specific explanation, see Black Tea Caffeine: How Much It Has and What Changes the Amount.


Leaf amount


More dry tea generally gives the brewing water access to more caffeine. Two tea bags in the same mug are not equivalent to one tea bag merely because the final volume is unchanged.


Tea-to-water ratio is therefore a major part of the dose.


Steeping time



That does not mean caffeine rises at a perfectly constant rate minute by minute. Extraction changes over time and is constrained by how much caffeine is available in the leaf.


Water temperature


Hotter water can alter extraction. A 2025 chromatographic study of multiple tea types found that brewing conditions affected caffeine and L-theanine concentrations, although the size and direction of individual effects depended on the tea and preparation condition. In that study, longer brewing increased caffeine in several conditions and cup-sized black-tea bags produced more caffeine than the tested loose-leaf preparation.


The practical point is not that one temperature always gives a universal caffeine number. It is that a caffeine estimate without a brewing protocol has limited precision.


Tea bag vs loose leaf


Bagged tea can differ from loose leaf in particle size, leaf dose, bag geometry, and water contact. Those factors can alter extraction.


The 2025 Ayakdaş and Ağagündüz study found higher caffeine in the tested cup-sized black-tea bags than in the tested loose-leaf black tea. That result should not be generalized into a rule that every tea bag contains more caffeine than every loose-leaf tea. Product dose and brewing design still matter.


Tea variety, growing conditions, and processing



This is one reason color alone cannot serve as a caffeine meter. A dark-looking cup is not an assay.


Why Coffee Caffeine Varies


Coffee has its own moving parts: bean species, dose of ground coffee, grind, brew ratio, extraction method, final beverage volume, and café recipe all matter.


The FDA’s 113–247 mg range for a 12-ounce regular brewed nonspecialty coffee already demonstrates how wide the category can be. A named café beverage may fall outside a generic table value because the recipe can use more coffee, more water, multiple espresso shots, a concentrate, or a different final volume.


That variation is owned in detail by How Much Caffeine Is in Coffee? Bean, Roast, Brew, Serving Size, and Why Effects Vary. Here, the important point is narrower: comparing a precisely measured black tea with an unspecified “coffee” can create false precision.


Why Dry Tea Leaves vs Coffee Beans Is the Wrong Comparison


You may encounter claims that tea leaves contain a surprising amount of caffeine by dry weight. That fact does not tell you which finished beverage has more caffeine.


People do not normally prepare tea and coffee using equal masses of dry material, equal extraction methods, and equal final liquid volumes. What matters to the drinker is the caffeine transferred into the beverage and the amount of beverage consumed.


A dry-material comparison answers a chemistry question. A cup-to-cup comparison answers a dietary-intake question.


For “black tea caffeine vs coffee,” the second is the relevant one.


Espresso vs Black Tea: Concentration Is Not the Same as Serving Dose


Espresso is a useful illustration of the concentration problem. The Mayo Clinic lists about 63 mg of caffeine in a 1-ounce espresso and 48 mg in 8 ounces of brewed black tea.


Per ounce, the espresso is dramatically more concentrated. But the whole espresso serving is only one ounce in that reference.


This is why you should never rank drinks using concentration alone when your real question is how much caffeine you will consume. The container and recipe determine the final dose.


Does Stronger Taste Mean More Caffeine?


Not reliably.


Black tea can taste strong because of bitterness, astringency, aroma intensity, body, temperature, or a high leaf-to-water ratio. Coffee can taste intense because of roast-derived flavor, concentration, extraction, temperature, or bitterness. Caffeine contributes bitterness, but it is only one component of each beverage’s sensory profile.


Perceived strength is therefore a poor caffeine measurement.


A strong-tasting black tea may contain less caffeine than a mild-tasting coffee. A coffee that tastes dark and intense is not automatically the higher-caffeine coffee. The sensory question and the dose question overlap imperfectly.


If your real interest is the broader sensory comparison, use Black Tea vs Coffee: Caffeine, Alertness, Taste, and Daily Routine. This page keeps the focus on caffeine quantity.


Does Adding Milk Change the Caffeine?


If the tea or coffee has already been brewed, adding milk does not remove the caffeine that was extracted into the beverage.


Milk can change total volume, concentration per ounce, temperature, texture, color, and taste. If you add milk to a fixed amount of brewed black tea, the total caffeine in the cup is essentially the caffeine that was already in the tea; you have diluted that caffeine into a larger liquid volume.


The same logic applies to coffee.


The more important question is whether milk changes how much brewed tea or coffee you actually use. A large milk-heavy drink may contain one small espresso shot; a large mug of milk tea may begin with a concentrated black-tea base. Recipe architecture matters more than the visual color of the finished drink.


What About Iced Black Tea?


Ice can lower caffeine concentration if melting ice adds water, but it does not remove caffeine that is already present.


Total caffeine depends on how the iced tea was made. A café may brew a strong concentrate and dilute it over ice. A bottled tea may have a manufacturer-specific formulation. Home iced tea may use several tea bags in a pitcher.


So “iced” is not a caffeine level. The relevant variables remain tea dose, extraction, dilution, and serving volume.


How Much Black Tea Equals One Coffee?


There is no universal conversion, but reference values can give a useful estimate.


Using Mayo Clinic’s representative amounts:


  • 8 oz brewed black tea: 48 mg;

  • 8 oz brewed coffee: 96 mg.


At those reference concentrations, about 16 ounces of black tea would provide the same total caffeine as 8 ounces of brewed coffee.


Using the FDA’s 12-ounce values gives a different comparison because its coffee category spans 113–247 mg while black tea is listed at 71 mg. One 12-ounce coffee could therefore correspond roughly to considerably more than one 12-ounce black tea.


The correct conversion for your own drinks requires the actual caffeine values or a reasonable product-specific estimate. Generic ratios are shortcuts, not measurements.


If You Are Switching from Coffee to Black Tea to Reduce Caffeine


Black tea can reduce caffeine intake if the serving size and preparation remain controlled. The substitution is not automatic.


If you replace one 8-ounce coffee with one 8-ounce black tea, the Mayo Clinic reference values suggest a reduction from about 96 mg to about 48 mg.


But if you replace an 8-ounce coffee with a 20-ounce black tea, or use multiple tea bags and long steeps, the reduction may be much smaller.


A practical approach is to compare total milligrams per actual serving rather than beverage names.


For a wider comparison of black tea and coffee as daily drinks, including taste and routine, use Black Tea vs Coffee. For the tea-wide caffeine map, use Caffeine in Tea: Black, Green, Matcha, Oolong, White, and Herbal Tea Compared.


Why Coffee Often Feels Stronger


One obvious reason is dose. If one drink contains substantially more caffeine, a stronger stimulant effect is plausible.



That evidence concerns caffeine as a drug, not a guarantee that one particular coffee will improve your performance more than one particular black tea. The actual caffeine dose, habitual use, time of day, sleep state, and task all matter.


Black tea can still produce measurable alerting effects


Black tea is not “non-stimulating” just because it usually has less caffeine than coffee. In two randomized double-blind crossover studies, De Bruin and colleagues found improved switch-task accuracy and self-reported alertness after black tea compared with a placebo tea.


This is beverage evidence, which is useful. It still does not establish a universal subjective profile for every black tea, because recipes, doses, participants, and contexts vary.


Does L-Theanine Make Tea Caffeine “Smoother”?


This popular claim needs more precision than it usually gets.



That does not justify saying that every cup of black tea produces “calm energy,” prevents jitters, or releases caffeine slowly.


The evidence categories must remain separate:


  • brewed black tea is a complex beverage with variable caffeine and L-theanine;

  • isolated caffeine studies test a controlled stimulant dose;

  • isolated L-theanine studies test a controlled amino-acid dose;

  • combination studies often use standardized doses that may not match an ordinary cup of tea.


The psychological experience of tea may differ from coffee, but the difference cannot be reduced to a slogan.


Tea Caffeine Is Not a Special Slow-Release Form of Caffeine


Caffeine in tea and caffeine in coffee are the same molecule.



So the common explanation that tea inherently “releases caffeine slowly” because it is tea is too simple.


Tea and coffee can still feel different because the dose can differ, the sensory experience differs, co-occurring compounds differ, drinking speed differs, and expectation differs. Those are separate mechanisms.


Expectation Can Change the Experience Without Changing the Caffeine Dose


The label “coffee” carries a learned expectation of stimulation for many people. Black tea can carry a different set of expectations: gentler, calmer, slower, or more ritualized.


Expectations do not change how many milligrams of caffeine are chemically present in the cup. They can, however, influence subjective experience and some behavioral outcomes.


In a double-blind experiment with 88 participants, Dawkins and colleagues found effects of both actual caffeine and the expectation of having consumed caffeine on attention, psychomotor speed, mood, and reward-related measures. The beverage used was coffee, so this is evidence about caffeine expectancy, not proof of a specific “black tea expectancy effect.”


The useful distinction is simple: measured dose belongs to chemistry; perceived intensity belongs to chemistry plus body state, learning, expectation, context, and attention to internal sensations.


Interoception: Why the Same Dose Can Feel Different on Different Days


Interoception is the perception of signals from inside the body: heartbeat, tension, alertness, stomach sensations, warmth, sleepiness, and arousal.


A person may interpret a racing heart as welcome energy on one day and as uncomfortable nervousness on another. The caffeine dose can be the same while the subjective meaning changes.


Several variables can alter the experience:


  • recent sleep;

  • habitual caffeine use;

  • whether caffeine was consumed quickly or slowly;

  • food intake;

  • current stress or arousal;

  • expectation;

  • individual sensitivity;

  • other caffeine consumed that day.


This is why subjective strength cannot be used to reverse-engineer caffeine content. Feeling “more wired” does not prove that the beverage contained more caffeine.


Caffeine, Anxiety-Like Symptoms, and Clinical Anxiety Are Not the Same Thing


Caffeine can produce ordinary stimulant effects such as alertness and increased arousal. At higher exposure or in sensitive people, it can also contribute to jitteriness, palpitations, restlessness, or anxiety-like feelings.



These are population-level findings about caffeine exposure. Feeling jittery after a strong coffee or tea is a symptom or physiological response, not a diagnosis of an anxiety disorder.


This distinction also prevents a common comparison error: black tea is not automatically “good for anxiety,” and coffee is not automatically “bad for anxiety.” Dose, sensitivity, context, and clinical history matter.


Caffeine and Sleep: Total Daily Dose Is Only Part of the Story


Timing matters as well as quantity.



This has a practical implication for black tea vs coffee: choosing the lower-caffeine beverage can reduce the dose, but a late black tea can still matter for a caffeine-sensitive sleeper.


The beverage name does not decide the sleep effect by itself. Total caffeine, timing, individual metabolism, sensitivity, and prior sleep all contribute.


Is Black Tea Better Than Coffee for Caffeine-Sensitive People?


It can be a useful lower-dose option because black tea usually contains less caffeine per equal volume. But “better” depends on the person’s goal and the actual drinks.


If your aim is simply to reduce caffeine while keeping a caffeinated hot beverage, an equal-size black tea often lowers the dose compared with brewed coffee.


If you are highly sensitive, even black tea may produce unwanted effects. Decaffeinated tea can still contain some caffeine, and herbal infusions are a separate category rather than automatically “decaf tea.”


For a broader map of tea categories and caffeine, see Caffeine in Tea.


How Much Caffeine Is Generally Considered Too Much?



These are population-level reference points, not a personal target or prescription. The FDA emphasizes that sensitivity and caffeine elimination vary among people and can also be affected by medications and health conditions.



The safest comparison method is to count caffeine from all sources, not just the drink currently in your hand.


Practical Comparison: Which Drink Fits Which Caffeine Goal?


You want the lower-caffeine choice at the same size


Black tea usually wins. Representative official and clinical reference tables consistently place brewed black tea below brewed coffee at comparable volume.


You want the strongest stimulant dose from one typical serving


Brewed coffee usually provides more caffeine, although the exact amount can vary widely.


You want to reduce coffee caffeine without giving up caffeine entirely


A same-size black tea is often a practical step down. Check your serving size and preparation rather than assuming the beverage name guarantees a specific reduction.


You drink very large mugs


Compare total milligrams, not the category. A large black tea can approach or exceed a smaller coffee.


You are concerned about sleep


Look at both dose and timing. Lower caffeine can help reduce exposure, but even a lower-dose drink may affect sleep if consumed late enough for your sensitivity.


You are prone to jitters or anxious arousal


Lowering the caffeine dose may reduce one possible trigger. A stimulant response is not the same as a clinical anxiety disorder, and black tea is not a treatment.


A Simple Way to Estimate Your Own Black Tea vs Coffee Caffeine


Use this sequence:


  • identify the actual serving size in ounces or milliliters;

  • find a product-specific caffeine value if one exists;

  • if only a reference concentration is available, scale it cautiously to your volume;

  • account for recipe changes such as extra tea bags, stronger concentrates, multiple coffee shots, or dilution;

  • add other caffeine consumed that day;

  • treat the result as an estimate unless the product has a measured or manufacturer-reported value.


The biggest practical mistake is often not the choice between tea and coffee. It is comparing a small reference cup with a much larger real drink.


Common Myths About Black Tea Caffeine vs Coffee


Myth: Coffee always has more caffeine than black tea


Coffee usually has more at equal volume. Serving-size and preparation differences can produce overlap, so “always” is too strong.


Myth: Tea has less caffeine because the dry leaf contains less caffeine


The finished beverage depends on dry-material dose, extraction, and final volume. Dry leaf vs dry bean is not the same question as brewed tea vs brewed coffee.


Myth: Darker tea means more caffeine


Color is influenced by many compounds and brewing variables. It is not a direct caffeine measurement.


Myth: Stronger taste means more caffeine


Sensory intensity and caffeine dose are partly independent. Bitterness, astringency, roast character, aroma, temperature, and concentration all shape perceived strength.


Myth: Adding milk removes caffeine


Milk can dilute concentration per ounce but does not remove caffeine already dissolved in the brewed beverage.


Myth: Tea caffeine is automatically slow-release


Caffeine is the same molecule across tea and coffee. Controlled evidence does not support a universal special slow-release mechanism for tea.


Myth: L-theanine guarantees that black tea cannot cause jitters


Research on caffeine and L-theanine is more nuanced. Experimental combination doses do not map perfectly onto every brewed cup, and individual responses vary.


Frequently Asked Questions


Does black tea have more caffeine than coffee?


Usually no. At equal serving sizes, brewed coffee generally contains more caffeine than brewed black tea. Mayo Clinic lists 48 mg in 8 ounces of brewed black tea and 96 mg in 8 ounces of brewed coffee, while the FDA lists 71 mg in 12 ounces of black tea and 113–247 mg in 12 ounces of regular brewed nonspecialty coffee.


How much caffeine is in black tea vs coffee per 8 ounces?


A useful mainstream reference is about 48 mg for brewed black tea and 96 mg for brewed coffee, according to Mayo Clinic. Individual products and brewing methods can differ substantially.


How much caffeine is in black tea vs coffee per 12 ounces?


The FDA lists a typical 12-ounce black tea at 71 mg and regular brewed nonspecialty coffee at 113–247 mg.


Can 16 ounces of black tea have as much caffeine as 8 ounces of coffee?


It can. Using the Mayo Clinic reference concentrations as an illustrative calculation, 16 ounces of black tea would be about 96 mg, equal to its 8-ounce brewed-coffee reference. Actual drinks may differ because concentration is not fixed.


Does steeping black tea longer increase caffeine?


Generally, longer steeping can increase caffeine extraction. The exact increase depends on tea dose, water temperature, leaf form, agitation, and other brewing variables.


Do two tea bags have more caffeine than one?


Usually they provide more available tea material and therefore the potential for more caffeine in the same volume of water. The exact amount depends on the bags, leaf mass, and brewing conditions.


Is espresso higher in caffeine than black tea?


Espresso is far more concentrated per ounce. A typical single espresso can also contain more total caffeine than an 8-ounce black tea, but its serving is much smaller than a brewed coffee. Always compare both concentration and total serving dose.


Does black tea caffeine absorb more slowly than coffee caffeine?


A universal “slow-release tea caffeine” claim is not supported. Caffeine is the same molecule, and a controlled study found similar caffeine pharmacokinetics across tea, coffee, and caffeinated water under its test conditions.


Why does black tea sometimes feel gentler than coffee?


Often because the caffeine dose is lower. Sensory context, drinking speed, expectation, habit, body state, and tea’s other compounds may also influence experience. None of those factors changes the need to compare the actual caffeine dose.


Does black tea give better focus than coffee?


There is evidence that caffeine can acutely improve attention, and controlled studies have found attention and alertness effects after black tea. That does not establish black tea as universally better for focus than coffee. Dose, person, task, tolerance, sleep, and context all matter.


Is black tea better for sleep than coffee?


An equal-size black tea usually contains less caffeine, which can reduce exposure. But caffeine from black tea can still affect sleep, especially when consumed near bedtime or by sensitive people.


Is black tea better for anxiety than coffee?


Black tea often contains less caffeine per equal volume, so it may produce a lower stimulant dose. That does not make black tea a treatment for anxiety. Caffeine-related jitteriness or anxious arousal is different from a clinical anxiety disorder.


Which has more caffeine: black tea, coffee, or green tea?


Coffee usually has the most caffeine per comparable brewed serving, black tea is generally lower, and green tea is often lower still, but all can vary. The broader category comparison belongs in Caffeine in Tea: Black, Green, Matcha, Oolong, White, and Herbal Tea Compared.


Is black tea healthier than coffee because it has less caffeine?


Lower caffeine is one property, not an overall health verdict. Black tea and coffee differ in composition, preparation, and evidence across many health outcomes. This article compares caffeine dose; the broader drink comparison is covered in Black Tea vs Coffee.


Bottom Line


Coffee usually has more caffeine than black tea when the same amount of brewed beverage is compared. Representative sources place 8 ounces of brewed black tea around 48 mg and 8 ounces of brewed coffee around 96 mg, while the FDA’s 12-ounce references are 71 mg for black tea and 113–247 mg for brewed coffee.


The decisive word is “serving.” A 16-ounce black tea can approach the caffeine in a smaller coffee. Stronger brewing, more tea leaf, extra tea bags, and longer extraction can raise black-tea caffeine; coffee recipes can vary even more widely. “One cup” is therefore an unreliable caffeine unit unless the volume and preparation are known.


For how much caffeine is in black tea itself, use Black Tea Caffeine: How Much It Has and What Changes the Amount. For the broader caffeine landscape across tea types, use Caffeine in Tea. For coffee-specific caffeine variability, use How Much Caffeine Is in Coffee?.


Related Articles







References


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