modulevsmouldWhich spelling fits?

Which to use

“module” and “mould” are a confusable English pair: similar on the page, but distinct in meaning, check the gloss before you choose.

#8,455
“module” frequency rank
#16,078
“mould” frequency rank
24533
confusion score

Side-by-Side Comparison

Feature module mould
Definition A self-contained component of a system, often interchangeable, which has a well-defined interface to the other components. Commonwealth standard spelling of mold.

Where the eye mixes module and mould

Muted = shared; highlighted = the visual trap. They share 4 letters in sequence.

6 ch
module
5 ch
mould

Visual trap between module and mould

A purely visual mix-up. module (/ˈmɒd͡ʒuːl/) and mould (/moʊld/) are said differently, so reading them aloud is the quickest way to catch the wrong one. On the page they stay close: they differ by 1 letter(s) in length. Our composite confusion score for this pair is 24533, derived from the frequency rank of both members and their visual similarity.

module is recorded at frequency rank #8,455, classified as anoun, pronounced /ˈmɒd͡ʒuːl/. mould is at rank #16,078, tagged as anoun, pronounced /moʊld/.

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 24533, this pair ranks #401,245 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of module vs mould

Shared letters: dlmou. Private to "module": e. Private to "mould": -.

"module" · 6 letters · shape CVCVCV  ·  "mould" · 5 letters · shape CVVCC

Known mistypes of this pair

  • modulemdoule · mmodule · moddule · modlue · moduel · modulle · moudle · omdule
  • mouldmmould · molud · moudl · mouldd · moulld · muold · omuld

Frequently Asked Questions

Is swapping "module" for "mould" ever safe?
No. They are said differently (/ˈmɒd͡ʒuːl/ versus /moʊld/) and carry different meanings; reading the sentence aloud is usually enough to catch the wrong one.
In ordinary English text, does "module" or "mould" show up more?
"module" is the more common of the two: it sits at frequency rank #8,455 in our English list, against #16,078 for "mould". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

What to do next

Eye-level mix-up between "module" and "mould" is sorted above. Next: full entries or other pairs that share a letter shape.

  • Full dictionary entry for "module" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "mould" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #401,245 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "module" and "mould" also get mixed up with nearby pairs, the highest-scored neighbour is "mould vs mudd". 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 #401,245 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