#  `update_info`

Update PDF metadata from `dump_data` instructions
## Usage
> pdftl `<input>` `update_info` `<metadata>` `output` `<filename>`

## Details
Updates the document-level metadata and structural
information of the input PDF by reading from a specified
`<metadata>` file (or stdin, if `<metadata>` is '-').
Alternatively, instructions can be specified in a structured
JSON file, loaded by setting `<metadata>` to
`@instructions.json`.

This operation consumes the plain-text format generated by
the `dump_data` command. It correctly parses the XML-escaped
strings created by that command.

This operation can read a full `dump_data` file in pdftk
'stanza' format, and will apply the following sections to
the output PDF:

* **Info:** Updates the Document Info dictionary (Title,
  Author, Subject, Keywords, CreationDate, ModDate, and
  custom keys).

* **Bookmarks:** Deletes all existing bookmarks and replaces
  them with the `Bookmark` stanzas from the input file.
  Target page numbers are 1-indexed.

* **PageMedia:** Applies page-level settings (Rotation,
  CropBox, TrimBox) as defined in `PageMedia` stanzas.
  Page numbers are 1-indexed.

* **PageLabels:** Replaces the document's page labelling
  scheme (e.g., "i, ii, iii") using the `PageLabel` stanzas
  from the input file. Indices are 1-indexed.

* **PdfID:** Updates the `PdfID0` top-level field (the
  creation ID).
  * You may provide a 32-character hex string to set a
      PdfID0. For example, `PdfID0: 1234abcd1234abcd1234abcd1234abcd`
  * **Fresh Bake:** If you set `PdfID0` to the string
      `RESET` (case-insensitive), the tool will remove
      the existing ID array. The underlying library will
      generate a brand new, matching ID pair (ID0=ID1)
      when saving.
  * `PdfID1` (the modification ID) is **not** updatable;
      it is automatically managed by the underlying PDF
      library to ensure specification compliance.

    Providing a `PdfID1` value in the input will result
    in a warning. It will otherwise be ignored.

For a complete description of the stanza-based input format
this command expects, see the help for `dump_data`.

The format of the JSON for `@instructions.json` is hopefully
intuitive. Key values for `update_info` should be
xml-escaped. (For `update_info_utf8` they should not be.)
Here is an example for `update_info`:

```
{
  "Info": {
    "Title": "Annual Financial Report &amp; Accounts 2025",
    "Author": "Acme Corp",
    "Subject": "Financial Data",
    "Keywords": "finance, report, 2025",
    "CustomKey": "Internal-ID-99"
  },
  "PdfID0": "38a4d9afd883e2750c63c2473ffd21e1",
  "BookmarkList": [
    {
      "Title": "Executive Summary",
      "Level": 1,
      "PageNumber": 1
    },
    {
      "Title": "Financial Statements",
      "Level": 1,
      "PageNumber": 5,
      "Children": [
        {
          "Title": "Income Statement",
          "Level": 2,
          "PageNumber": 6
        },
        {
          "Title": "Balance Sheet",
          "Level": 2,
          "PageNumber": 8
        }
      ]
    }
  ],
  "PageMediaList": [
    {
      "PageNumber": 1,
      "Rotation": 90
    }
  ],
  "PageLabelList": [
    {
      "Index": 1,
      "Style": "LowercaseRoman",
      "Start": 1
    },
    {
      "Index": 5,
      "Style": "DecimalArabic",
      "Start": 1
    }
  ]
}
```

Where it makes sense, you can omit keys in order to perform
a partial update.
## Examples

> Update metadata according to meta.txt
```
pdftl in.pdf update_info meta.txt output out.pdf
```


**Tags**: info, metadata

*Source: pdftl.operations.update_info*

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

*Type: Operation*