Which to use
“infill” and “instill” are a confusable English pair: similar on the page, but distinct in meaning, check the gloss before you choose.
- #48,290
- “infill” frequency rank
- #28,958
- “instill” frequency rank
- 77248
- confusion score
Side-by-Side Comparison
| Feature | infill | instill |
|---|---|---|
| Definition | To fill in a space, hole or gap. | To cause a quality to become part of someone's nature. |
Letter map: infill vs instill
Shared letters muted; letters that set infill and instill apart highlighted. Shared run: 5. infill runs 6 letters (VCCVCC) against instill's 7 (VCCCVCC) - the length gap alone is often enough to separate them once you know to check it.
Pair insight - infill / instill
infill and instill are indexed as a confusable English pair. We have no recorded pronunciation or part of speech for both members, so the spelling overlap is what we can show you: they differ by 1 letter(s) in length. Our composite confusion score for this pair is 77248, derived from the frequency rank of both members and their visual similarity.
infill is recorded at frequency rank #48,290, classified as averb. instill is at rank #28,958, tagged as averb, pronounced /ɪnˈstɪl/.
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 77248, this pair ranks #27,776 of 530,003 scored English confusable pairs - among the most confusable pairs.
Orthographic DNA of infill vs instill
Shared letters: iln. Private to "infill": f. Private to "instill": st.
"infill" · 6 letters · shape VCCVCC · "instill" · 7 letters · shape VCCCVCC
Known mistypes of this pair
Frequently Asked Questions
Is swapping "infill" for "instill" ever safe?
In ordinary English text, does "infill" or "instill" show up more?
Useful next steps
You've compared "infill" and "instill". Here's where to go from here.
- Full dictionary entry for "infill" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "instill" - compare definitions side by side with the headword page. Word entry
- This pair ranks #27,776 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
- "infill" and "instill" also get mixed up with nearby pairs, the highest-scored neighbour is "infill 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 #27,776 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.