iOS
"ios" is a 3-letter English headword indexed on PlainSpell.
The verdict
“iOS” is a regularly-used English word, ranked #5,888 in English word frequency and used as a proper noun.
- #5,888
- frequency rank, English
- 3
- letters
- 20
- confusable pairs
According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - A mobile operating system (OS) created and developed by Apple Inc. exclusively for its hardware.
Visual similarity to commonly confused words
How many letter changes separate each confused pair (Levenshtein distance, normalized).
Source: PlainSpell confusable corpus (Wiktionary, CC BY-SA).
| Property | Value |
|---|---|
| Headword | iOS |
| Language | English |
| Part of speech | Proper noun |
| Letters | 3 |
| Frequency rank | #5,888 |
| Misspellings tracked | 0 |
| Confusable pairs | 20 |
| Source | Wiktionary (kaikki.org) |
Where “iOS” sits in English frequency
Spelling & Dictionary Insight
The English entry for iOS is 3 letters long, classified as a proper noun. Corpus data places it at rank #5,888 in overall English word frequency, indicating it appears regularly in written and spoken text. The dominant gloss from Wiktionary reads: "A mobile operating system (OS) created and developed by Apple Inc. exclusively for its hardware.".
Our edit-distance generator produced no likely misspellings for iOS, and the word's spelling is regular enough that our generator found nothing worth flagging. It also participates in 20 confusable-pair relationships, "is", "it", "IV", and more, where similar look or sound leads writers to substitute one word for another in context.
Etymologically, the entry records: From i- + OS. Many Apple products have an i- prefix in their names. The correct English form is iOS, spelled I-O-S.
Definition
- 1A mobile operating system (OS) created and developed by Apple Inc. exclusively for its hardware.
Etymology
From i- + OS. Many Apple products have an i- prefix in their names.
Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA); frequency ordering uses the FrequencyWords open word-frequency list (2018 English corpus, MIT). See the methodology for how each field is sourced and updated.
Frequently Asked Questions
How do you spell "iOS"?
What does "iOS" mean?
What words are commonly confused with "iOS"?
What is the origin of the word "iOS"?
Is PlainSpell free to use?
Using “iOS”
The practical upshot for anyone who landed here from a spell-check.
- The one correct English spelling is I-O-S - every other letter order is a misspelling in standard orthography.
- Don't mix it up with “is” - see the side-by-side comparison. iOS vs is
- Browse more English words and confusable pairs in the same reference. English words
Data Source
Wiktionary (via kaikki.org), licensed under CC BY-SA & GFDL. Word ordering uses an open word-frequency list; misspelling variants are generated by edit-distance from the correct headword.