What is the difference between V.O. and O.S.?
O.S. (off screen) means the character is physically present in the scene but we can't see them, such as a voice from the next room. V.O. (voice over) means the voice isn't in the scene at all, such as narration, a phone call heard through a speaker or a character's thoughts.
Examples
TOM (O.S.)
Mags? The boats are still out there.
Tom is shouting up the stairwell: he's in the scene, just out of view.
MAGGIE (V.O.)
I kept that light burning for forty years.
Older Maggie narrating over the scene: not physically present.
O.C.
O.C. (off camera) is mainly used in TV and means the same as O.S.
The difference in one sentence
O.S. (off screen) means the character is physically present in the scene but not visible in the shot, such as someone shouting from the next room. V.O. (voice over) means the voice is not part of the scene at all: narration, a character's inner thoughts, or a voice heard through a phone, radio or recording.
Examples
TOM (O.S.)
Mara? Is that you?
Mara freezes on the stairs.
MARA (V.O.)
I should have answered him. I
should have said anything at all.
Tom is upstairs in the same house: off screen. Mara's line is her future self narrating: voice over.
O.C., phones and recordings
- O.C. (off camera) means the same as O.S. and is mostly used in TV. Pick one and be consistent.
- Phone calls: if we only hear the other person through the phone, their lines are usually
(V.O.)or(ON PHONE). If we cut between both ends, use an intercut instead and give both characters normal dialogue. - Recordings and broadcasts: a voice on a radio, TV or answering machine is
(V.O.), sometimes written as(ON TV)or(ON RADIO)for clarity.
Using voice over well
Voice over narration has a reputation for being a crutch, because it is easy to use it to explain what the pictures should show. Used well, it adds something the images can't: irony, a character's private view, or a gap between what is said and what we see. If your narration only describes what is on screen, try cutting it and see whether the scene still works.
Formatting
The extension goes in brackets on the same line as the character name, in capitals, not as a parenthetical underneath. In True-Script, type the extension after the character's name. Table Read treats "MARA (V.O.)" and "MARA" as the same person, so the narration keeps the character's voice.
Common questions
Is a phone call V.O. or O.S.?
The voice of someone on the other end of a phone call, heard through the speaker, is usually written as V.O.
Is a phone voice V.O. or O.S.?
A voice heard only through a phone is usually V.O., because the speaker is not in the location. If both ends of the call are shown, use an intercut instead.
Can a character have both V.O. and normal dialogue?
Yes. Many films use a narrator who also appears in scenes. Their narration is marked V.O. and their on-screen lines have no extension.