Chlorine taste is the single most common thing people want fixed, and it is the easiest to fix — provided you use the right kind of carbon.
Getting that wrong is why some filters seem to do nothing.
Why it is there on purpose
A disinfectant residual has to persist all the way through the distribution system. Water leaving a plant clean can pick up contamination from a main break, a pressure drop, or a cross-connection on the journey. The residual is what protects the last house on the line.
So the taste is evidence of a functioning system, not a failure of one. What varies is how much residual is needed — longer distribution runs need more at the plant to still have some at the end — and how sensitive you are. Detection thresholds differ enough between people that one household is untroubled and the next finds the same water undrinkable.
Three different disinfectants, three different problems
Free chlorine is the classic. Volatile, so it dissipates from an open pitcher in a few hours, and it is removed easily by ordinary activated carbon.
Chloramine — chlorine combined with ammonia — is used where a system needs the residual to last longer and produce fewer by-products. It is much more stable, which is the point and also the difficulty: it does not gas off in the fridge and standard activated carbon removes it poorly.
Chlorine dioxide is used by some systems and leaves chlorite behind as a by-product, which is separately regulated.
The distinction matters commercially. A homeowner on chloramine who buys a standard carbon filter gets a small improvement, concludes filtration does not work, and stops. The filter was fine; it was the wrong filter.
Which one do you have?
Two quick tests, no equipment:
The fridge test. Fill an open pitcher, leave it several hours, taste it. Much better means free chlorine. Barely changed means chloramine.
Ask the utility, or read the report. The system's profile says which disinfectant is used, and it is the single most useful thing to know before buying anything.
What actually removes it
Free chlorine — activated carbon, in almost any form. A pitcher, a fridge filter, an under-sink cartridge, a whole-house tank. This is a solved problem.
Chloramine — catalytic carbon specifically, with enough contact time. The media is different from standard activated carbon and so is the sizing; a too-small unit run at full flow will underperform regardless of media.
Whole-house versus under-sink is a real decision here. Chlorine and by-products are volatile, so a hot shower is a genuine exposure route rather than a marginal one. If the goal is only better-tasting drinking water, under-sink is cheaper and sufficient. If the shower is part of the complaint, it has to be whole-house.
What will not fix it
Reverse osmosis alone is the wrong tool — and worse, chlorine damages some membranes, which is why RO systems have a carbon prefilter. The carbon is doing the chlorine work in that setup.
A softener does nothing for chlorine. Different mechanism entirely.
The free in-home test reads the chlorine residual at your tap, which is what decides the size rather than the average across a whole city.