codecvscodexWhich spelling fits?

Which to use

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

#43,084
“codec” frequency rank
#22,932
“codex” frequency rank
66016
confusion score

Side-by-Side Comparison

Feature codec codex
Definition A device or program capable of performing transformations on a data stream or signal. An early manuscript book.

Letter map: codec vs codex

Shared letters muted; letters that set codec and codex apart highlighted. Shared run: 4.

5 ch
codec
5 ch
codex

Pair insight - codec / codex

codec and codex 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 a single letter - c in “codec” becomes x in “codex”. Our composite confusion score for this pair is 66016, derived from the frequency rank of both members and their visual similarity.

codec is recorded at frequency rank #43,084, classified as anoun. codex is at rank #22,932, tagged as anoun, pronounced /ˈkəʊdɛks/.

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 66016, this pair ranks #70,018 of 530,003 scored English confusable pairs - among the most confusable pairs.

Orthographic DNA of codec vs codex

Shared letters: cdeo. Private to "codec": -. Private to "codex": x.

"codec" · 5 letters · shape CVCVC  ·  "codex" · 5 letters · shape CVCVC

Known mistypes of this pair

  • codecccodec · cdoec · codce · coddec · codecc · coedc · ocdec
  • codexccodex · cdoex · coddex · codexx · codxe · coedx · ocdex

Frequently Asked Questions

Do "codec" and "codex" mean the same thing in a sentence?
No. They differ by a single letter - c in “codec” becomes x in “codex”, but the dictionary glosses above give them different meanings, so swapping one for the other changes what the sentence says.
Frequency check: "codec" vs "codex" - which ranks higher?
"codex" is the more common of the two: it sits at frequency rank #22,932 in our English list, against #43,084 for "codec". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

After this comparison

Done with this confusable. These links stay specific to "codec" and "codex".

  • Full dictionary entry for "codec" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "codex" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #70,018 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "codec" and "codex" also get mixed up with nearby pairs, the highest-scored neighbour is "codec vs cower". 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 #70,018 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