cost vs CSI, What's the Difference?

Which to use

“cost” is a verb and “CSI” is a noun - they look or sound alike but fill different roles in a sentence.

#568
“cost” frequency rank: #20,894
“CSI” frequency rank: 21462
confusion score

Side-by-Side Comparison

Feature	cost	CSI
Definition	To incur a charge of; to require payment of a (specified) price.	Initialism of crime scene investigation (a term of forensic science).

Letter map: cost vs CSI

Shared letters muted; letters that set cost and CSI apart highlighted. Shared run: 2.

4 ch

cost

3 ch

CSI

Grammar separator: cost vs CSI

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: cost is averb and CSIanoun. On the page they differ by 1 letter(s) in length. Our composite confusion score for this pair is 21462, derived from the frequency rank of both members and their visual similarity.

cost is recorded at frequency rank #568, classified as averb, pronounced /ˈkɒst/. CSI is at rank #20,894, tagged as anoun.

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 21462, this pair ranks #423,721 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of cost vs CSI

Shared letters: cs. Private to "cost": ot. Private to "CSI": i.

"cost" · 4 letters · shape CVCC · "CSI" · 3 letters · shape CCV

Known mistypes of this pair

cost ← ccost · cosst · costt · cots · csot · ocst

Frequently Asked Questions

Is swapping "cost" for "CSI" ever safe?

No - they are not even the same part of speech. "cost" is a verb and "CSI" a noun, so a sentence built for one is usually ungrammatical with the other.

Which is more common, "cost" or "CSI"?

"cost" is the more common of the two: it sits at frequency rank #568 in our English list, against #20,894 for "CSI". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

After this comparison

You've compared "cost" and "CSI". Here's where to go from here.

Full dictionary entry for "cost" with definition, IPA, and generated misspellings. Word entry
Full dictionary entry for "CSI" - compare definitions side by side with the headword page. Word entry
This pair ranks #423,721 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
"cost" and "CSI" also get mixed up with nearby pairs, the highest-scored neighbour is "CGT vs CSI". 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 #423,721 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.