# onto

> English word · Preposition · IPA /ˈɒn.tuː/ · frequency rank #1,768

## Definitions
1. Arriving upon or on top of (speaking of a physical or metaphorical movement).
2. Aware of.
3. Being an onto function with a codomain of (see below).

## Etymology
From on + to, after into. Compare Saterland Frisian antou (“up to”).

## Easily confused with
- **OT** (https://plainspell.com/en/vs/onto-vs-ot)
- **oo** (https://plainspell.com/en/vs/onto-vs-oo)
- **out** (https://plainspell.com/en/vs/onto-vs-out)
- **opt** (https://plainspell.com/en/vs/onto-vs-opt)
- **OOO** (https://plainspell.com/en/vs/onto-vs-ooo)
- **OST** (https://plainspell.com/en/vs/onto-vs-ost)
- **OTC** (https://plainspell.com/en/vs/onto-vs-otc)
- **OTT** (https://plainspell.com/en/vs/onto-vs-ott)
- **Ota** (https://plainspell.com/en/vs/onto-vs-ota)
- **oth** (https://plainspell.com/en/vs/onto-vs-oth)
- **oot** (https://plainspell.com/en/vs/onto-vs-oot)
- **oso** (https://plainspell.com/en/vs/onto-vs-oso)
- **OTS** (https://plainspell.com/en/vs/onto-vs-ots)
- **OTP** (https://plainspell.com/en/vs/onto-vs-otp)
- **otto** (https://plainspell.com/en/vs/onto-vs-otto)
- **Oslo** (https://plainspell.com/en/vs/onto-vs-oslo)
- **onus** (https://plainspell.com/en/vs/onto-vs-onus)
- **onyx** (https://plainspell.com/en/vs/onto-vs-onyx)
- **Oreo** (https://plainspell.com/en/vs/onto-vs-oreo)
- **oppo** (https://plainspell.com/en/vs/onto-vs-oppo)

## Common misspellings (5)
`noto`, `onnto`, `onot`, `ontto`, `otno`

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/onto