> ## Documentation Index
> Fetch the complete documentation index at: https://learn.nextedy.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Configuring File Types

> Change which file extensions Nextedy MEDIAKIT treats as images and which it recognises as other media.

export const LastReviewed = ({date}) => {
  if (!date) return null;
  const formatted = new Date(`${date}T00:00:00Z`).toLocaleDateString("en-US", {
    year: "numeric",
    month: "long",
    day: "numeric",
    timeZone: "UTC"
  });
  return <p className="mt-10 text-sm text-gray-400 dark:text-zinc-500 not-prose">
      Last reviewed on {formatted}
    </p>;
};

Mediakit decides how to present a file from its **extension**. Extensions it maps to an image type get a thumbnail; extensions it maps to any other known type get an icon for that type. Both maps have sensible defaults, and both can be replaced.

You would change them to add a format your teams use that is not recognised by default, or to stop treating a format as an image.

## Prerequisites

* Administrator access to the Polarion server configuration
* Permission to restart the Polarion service

## The Two Properties

| Property                   | Controls                                                                       |
| -------------------------- | ------------------------------------------------------------------------------ |
| `nextedy.files.imagemimes` | Extensions treated as **images** — these render a thumbnail and open full size |
| `nextedy.files.othermimes` | Extensions recognised as **other media** — these render a type icon            |

Both are Polarion system properties, and both take the same format: `extension=mimetype` pairs separated by semicolons.

```
apng=image/apng;bmp=image/bmp;gif=image/gif;png=image/png
```

## Replace, Don't Extend

<Warning>
  **Setting a property replaces the whole default list — it does not add to it.**

  Whatever you set becomes the complete map. If you set `nextedy.files.imagemimes` to a single pair, that one extension is the only one treated as an image, and every other image format loses its thumbnail.

  To add a format, take the full default list from [Supported File Types](/mediakit/reference/supported-file-types), append your pair, and set the result.
</Warning>

## Apply a Change

<Steps>
  <Step title="Compose the full value">
    Start from the current default list, add or remove pairs, and keep the `extension=mimetype;…` format.
  </Step>

  <Step title="Set the system property">
    Add the property to your Polarion configuration alongside the server's other system properties.
  </Step>

  <Step title="Restart Polarion">
    Restart the service so the new value is read, then reload a work item with the gallery to confirm the file type now presents as you intended.
  </Step>
</Steps>

## Related

<Card title="Supported File Types" icon="file-lines" href="/mediakit/reference/supported-file-types">
  The complete default lists for both properties.
</Card>

<LastReviewed date="2026-09-03" />