ISDNvsISISTell them apart

Which to use

“ISDN” and “ISIS” are a confusable German pair: similar on the page, but distinct in meaning, check the gloss before you choose.

#31,114
“ISDN” frequency rank
#7,491
“ISIS” frequency rank
38605
confusion score

Side-by-Side Comparison

Feature ISDN ISIS
Definition Internationaler Standard für digitale Telekommunikationsnetze Abkürzung für die Terrorgruppe „Islamischer Staat im Irak und Syrien“ bzw. „Islamischer Staat im Irak und in Syrien“ bzw. „Islamischer Staat im Irak und in (Groß-)Syrien“

Letter map: ISDN vs ISIS

Shared letters muted; letters that set ISDN and ISIS apart highlighted. Shared run: 2. ISDN (VCCC) and ISIS (VCVC) run the same length but a different consonant-vowel pattern - the shape difference is usually the fastest tell.

4 ch
ISDN
4 ch
ISIS

Spelling & dictionary notes on ISDN vs ISIS

ISDN and ISIS are indexed as a confusable German pair. We have no recorded pronunciation or part of speech for both members, so the spelling overlap is what we can show you: they share most of their letters but differ in 2 positions. Our composite confusion score for this pair is 38605, derived from the frequency rank of both members and their visual similarity.

ISDN is recorded at frequency rank #31,114, classified as anabbrev, pronounced [ˌiːʔɛsdeːˈʔɛn]. ISIS is at rank #7,491, tagged as anabbrev.

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 38605, this pair ranks #1,559,545 of 2,006,359 scored German confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of ISDN vs ISIS

Shared letters: is. Private to "ISDN": dn. Private to "ISIS": -.

"ISDN" · 4 letters · shape VCCC  ·  "ISIS" · 4 letters · shape VCVC

Known mistypes of this pair

  • ISDN ← idsn · isddn · isdnn · issdn
  • ISIS ← iiss · isiss · issi · issis · siis

Frequently Asked Questions

Can "ISDN" and "ISIS" be used interchangeably?
No. They share most of their letters but differ in 2 positions, but the dictionary glosses above give them different meanings, so swapping one for the other changes what the sentence says.
Which is more common, "ISDN" or "ISIS"?
"ISIS" is the more common of the two: it sits at frequency rank #7,491 in our German list, against #31,114 for "ISDN". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

After this comparison

You've compared "ISDN" and "ISIS". Here's where to go from here.

  • Full dictionary entry for "ISDN" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "ISIS" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #1,559,545 of 2,006,359 scored German confusable pairs in this corpus vintage. Corpus statistics
  • "ISDN" and "ISIS" also get mixed up with nearby pairs, the highest-scored neighbour is "idF vs ISDN". 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 #1,559,545 of 2,006,359 scored German pairs, corpus vintage 2026-09-03, not spelling advice.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list