#  `set`

Set document properties, viewer preferences, and page labels
## Usage
> pdftl `<input>` `set` `<key=value>...` `output` `<file>`

## Details
The `set` operation allows you to modify document-level properties, viewer
preferences, logical page labels, and open actions without altering page content.

You can provide one or more `key=value` pairs.

### Document Metadata (Auto-syncs Info Dict & XMP Stream)
Updates standard metadata properties. pdftl automatically synchronizes these
values across both the legacy `/Info` dictionary and the modern PDF 2.0 XMP stream.
* **title**: The document's title.
* **author**: The name of the person who created the document.
* **subject**: The subject of the document.
* **keywords**: Comma-separated keywords associated with the document.
* **creator**: The application that originally created the document.
* **producer**: The tool used to convert the document to PDF.
* **creationdate**: Document creation timestamp (ISO 8601 or PDF `D:...` date).
* **moddate**: Document modification timestamp (ISO 8601 or PDF `D:...` date).

### Supported Properties
* **lang**: The language identifier of the document (e.g., `en-US`). Important for accessibility.
* **layout**: The page layout to use when opened.
  *(SinglePage, OneColumn, TwoColumnLeft, TwoColumnRight, TwoPageLeft, TwoPageRight)*
* **mode**: The document view mode when opened.
  *(UseNone, UseOutlines, UseThumbs, FullScreen, UseOC, UseAttachments)*

### Viewer Preferences (Booleans)
These control how the PDF reader UI is presented:
* **hide_toolbar**: `true` or `false`
* **hide_menubar**: `true` or `false`
* **hide_windowui**: `true` or `false`
* **fit_window**: `true` or `false`
* **center_window**: `true` or `false`
* **display_title**: `true` or `false` (Displays the Document Title instead of filename)

### Open Action (`open_action`)
Determines the page and zoom level the PDF viewer initially opens to.
Syntax: `PageNum[,ViewType,Arg1,Arg2...]`
* `open_action=5` (Opens to page 5, leaving the zoom level up to the viewer)
* `open_action=2,XYZ,null,null,2.5` (Opens to page 2, zoomed in 2.5x)
* `open_action=5,XYZ` (Opens to page 5, trailing nulls are automatically appended)
* `open_action=1,Fit` (Opens to page 1, fitting it to the window)
* `open_action=""` (Removes the open action entirely)

### Page Labels (`pagelabels`)
Logical page labels determine how page numbers are displayed in the PDF viewer
(e.g., i, ii, iii, 1, 2, 3, A-1).

Syntax: A comma-separated list of rules.
Rule format: `<StartPage>[ (Prefix) ][Style][StartNum]`
* **StartPage**: 1-indexed physical page number.
* **Prefix**: Optional text prefix enclosed in parentheses.
* **Style**: Optional numbering style:
  `r` (roman), `R` (ROMAN), `a` (letters), `A` (LETTERS), `D` (Arabic).
* **StartNum**: Optional starting number (defaults to 1).

To completely remove custom page labels, use `pagelabels=""`.
## Examples

> Set the document title/author, and tell the viewer to display the Title instead of the filename.
```
pdftl in.pdf set title="Q3 Report" author="Jane Doe" display_title=true output out.pdf
```

> Set language to US English and force the PDF to open in a two-column view with bookmarks open.
```
pdftl in.pdf set lang=en-US layout=TwoColumnRight mode=UseOutlines output out.pdf
```

> Force the PDF to automatically open to Page 5 at a 2.5x zoom level.
```
pdftl in.pdf set open_action=5,XYZ,null,null,2.5 output out.pdf
```

> Set complex page labels: pages 1-4 as roman numerals, pages 5-7 as arabic starting at 1, and pages 8 onwards as arabic prefixed with 'A-' and starting at 8.
```
pdftl in.pdf set 'pagelabels=1r,5D,8(A-)D8' output out.pdf
```


**Tags**: metadata, properties, viewer

*Source: pdftl.operations.set_props*

*Read online: [https://pdftl.readthedocs.io/en/stable/operations/set.html](https://pdftl.readthedocs.io/en/stable/operations/set.html)*

*Type: Operation*