indexvsinferTell them apart

Quick tell: index is a noun, infer is a verb, so they fill different roles in a sentence.

Which to use

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

#2,628
“index” frequency rank
#23,568
“infer” frequency rank
26196
confusion score

Side-by-Side Comparison

Feature index infer
Definition An alphabetical listing of items and their location. To introduce (something) as a reasoned conclusion; to conclude by reasoning or deduction, as from premises or evidence.

Where the eye mixes index and infer

Muted = shared; highlighted = the visual trap. They share 3 letters in sequence.

5 ch
index
5 ch
infer

Why the eye confuses index with infer

These two trip readers on the page rather than in the ear: index is /ˈɪndɛks/ while infer is /ɪnˈfɜː/. 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 verb), which is usually the fastest check. Our composite confusion score for this pair is 26196, derived from the frequency rank of both members and their visual similarity.

index is recorded at frequency rank #2,628, classified as anoun, pronounced /ˈɪndɛks/. infer is at rank #23,568, tagged as averb, pronounced /ɪnˈfɜː/.

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 26196, this pair ranks #388,503 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of index vs infer

Shared letters: ein. Private to "index": dx. Private to "infer": fr.

"index" · 5 letters · shape VCCVC  ·  "infer" · 5 letters · shape VCCVC

Known mistypes of this pair

  • indexidnex · inddex · indexx · indxe · inedx · inndex · nidex
  • inferinefr · inferr · inffer · infre · innfer · nifer

Frequently Asked Questions

Do "index" and "infer" mean the same thing in a sentence?
No - they are not even the same part of speech. "index" is a noun and "infer" a verb, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "index" or "infer"?
"index" is the more common of the two: it sits at frequency rank #2,628 in our English list, against #23,568 for "infer". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

After this comparison

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

  • Full dictionary entry for "index" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "infer" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #388,503 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "index" and "infer" also get mixed up with nearby pairs, the highest-scored neighbour is "infer vs infirm". 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 #388,503 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