On site or onsite?
on site is a prepositional phrase meaning “At the site of a job, or at the location of the customer of a product or…”; onsite is an adjective meaning “On or at a site”. Use on site as a prepositional phrase and onsite as an adjective (on site is also an adjective: “On a particular site or in a particular building, as…”). on site is written as two words and onsite as one word; they are used differently.
What is the difference between on site and onsite?
| on site | onsite | |
|---|---|---|
| Part of speech | prepositional phrase, adjective | adjective, adverb |
| Meaning | At the site of a job, or at the location of the customer of a product or service, as opposed to at the vendor's factory, office, or studio On a particular site or in a particular building, as opposed to at a remote site or factory | On or at a site |
| Example | If we can't figure out how to diagnose this problem remotely, we're going to have to go on site again | none recorded |
| Forms | onsite | none |
| Pronunciation | not recorded | not recorded |
| In writing | not counted (the list counts single words) | about once in every 1 million words |
Sources: on site and onsite in the English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0); written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
Every current meaning of on site and onsite
on site
- 1
At the site of a job, or at the location of the customer of a product or service, as opposed to at the vendor's factory, office, or studio
If we can't figure out how to diagnose this problem remotely, we're going to have to go on site again
- 2
On a particular site or in a particular building, as opposed to at a remote site or factory
Our supplier offers on-site support
onsite
- 1
On or at a site
- 2
On or at a site
Source: the English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0); obsolete, archaic, dialect and rare senses left out.
Which is more common, on site or onsite?
on site is a phrase, which the list of single words does not count; onsite about once in every 1 million words.
Source: written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How many people search on site vs onsite?
“on site vs onsite” is searched about 80 times a month on Bing (Google reports it together with close variants, so it has no figure of its own) in the United States.
Sources: Google Ads keyword data through DataForSEO and Microsoft Advertising keyword data through DataForSEO, the average month from September 2025 to August 2026.