English UsageComparison guide

Complementary vs. Complimentary

“Complementary” and “complimentary” sound alike but have different meanings. “Complementary” describes things that complete or work well with each other, while “complimentary” can mean praising or given free of charge.

Quick answer

Use “complementary” when two things work well together; use “complimentary” for praise or something provided free.

Key details

Complementary Coreworks well with or completes something else
Complimentary Coreexpresses praise or is provided free of charge
Termscomplementary, complimentary

Choose the right form

Decision table for Complementary vs. Complimentary
If you mean / needUseWhy
things that complete or suit one anothercomplementaryIt is related to complement.
praise or something given freecomplimentaryIt is related to compliment or the “free of charge” sense.

Further guidance

Core difference

Use “complementary” for things that fit together or complete one another. Use “complimentary” for praise or for something given free of charge.

Fast Test

Think “complement” for completion and “compliment” for praise. If a hotel gives you a free breakfast, it is complimentary.

Meaning Boundary

“Complimentary” has two common senses—praising and free—so context determines which one is intended.

Sources and evidence

Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.

  1. Complementary — English meaning (opens in a new tab)Cambridge University Press · Dictionary meaning of complementary as working well together or completing another thing
  2. Complimentary — English meaning (opens in a new tab)Cambridge University Press · Dictionary meanings of complimentary as praising or provided free of charge

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