---
title: "Wide atom ('wide')"
framework: QuickTime File Format
role: symbol
role_heading: Atom
path: quicktime-file-format/wide_atom
---

# Wide atom ('wide')

An atom that designates reserved space in the movie data file.

## Overview

Overview A wide atom typically precedes a movie data atom. The wide atom consists only of a type and size field. This occupies 8 bytes—enough space to add an extended size field to the header of the atom that follows, without displacing the contents of that atom. If an atom grows to exceed 2^32 bytes in size, and it is preceded by a wide atom, you may create a new atom header containing an extended size field by overwriting the existing atom header and the preceding wide atom.

## Topics

### Data fields

- [Size](quicktime-file-format/wide_atom/size.md)
- [Type](quicktime-file-format/wide_atom/type.md)

## See Also

### Setting free space

- [Free space atom](quicktime-file-format/free_space_atom.md)
- [Skip atom](quicktime-file-format/skip_atom.md)