reactionvsreactiveWhat's the difference?

Quick tell: reaction is a noun, reactive is an adjective, so they fill different roles in a sentence.

Which to use

“reaction” is a noun and “reactive” is an adjective - they look or sound alike but fill different roles in a sentence.

#1,915
“reaction” frequency rank
#14,199
“reactive” frequency rank
16114
confusion score

Side-by-Side Comparison

Feature reaction reactive
Definition An action or statement in response to a stimulus or other event. That reacts or responds to a stimulus.

Where the eye mixes reaction and reactive

Muted = shared; highlighted = the visual trap. They share 6 letters in sequence.

8 ch
reaction
8 ch
reactive

Why the eye confuses reaction with reactive

These two trip readers on the page rather than in the ear: reaction is /ɹiˈækʃən/ while reactive is /ɹiːˈæktɪv/. Spoken aloud the problem disappears. In writing it persists, because they share most of their letters but differ in 2 positions, and the parts of speech differ too (noun vs adjective), which is usually the fastest check. Our composite confusion score for this pair is 16114, derived from the frequency rank of both members and their visual similarity.

reaction is recorded at frequency rank #1,915, classified as anoun, pronounced /ɹiˈækʃən/. reactive is at rank #14,199, tagged as anadj, pronounced /ɹiːˈæktɪv/.

Glosses for this pair are partially populated in our dataset, but the full side-by-side definitions above should still guide you to the right choice.

With a confusion score of 16114, this pair ranks #459,812 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of reaction vs reactive

Shared letters: aceirt. Private to "reaction": no. Private to "reactive": v.

"reaction" · 8 letters · shape CVVCCVVC  ·  "reactive" · 8 letters · shape CVVCCVCV

Known mistypes of this pair

  • reactioneraction · raection · reacction · reaciton · reacsion · reactino · reactionn · reactoin
  • reactiveeractive · raective · reacctive · reacitve · reactiev · reactivve · reacttive · reactvie

Frequently Asked Questions

Do "reaction" and "reactive" mean the same thing in a sentence?
No - they are not even the same part of speech. "reaction" is a noun and "reactive" an adjective, so a sentence built for one is usually ungrammatical with the other.
In ordinary English text, does "reaction" or "reactive" show up more?
"reaction" is the more common of the two: it sits at frequency rank #1,915 in our English list, against #14,199 for "reactive". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

What to do next

Visual near-miss handled. Browse the word pages or a neighbour when the next look-alike shows up.

  • Full dictionary entry for "reaction" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "reactive" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #459,812 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "reaction" and "reactive" also get mixed up with nearby pairs, the highest-scored neighbour is "reactivate vs reactive". Nearby pair
  • Recorded mistypes exist for at least one side of this pair, useful when a spell-checker or OCR lands on the wrong form. See mistypes

Confusion rank #459,812 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list