# Thumbnails
## Introduction
When sending media, it is often helpful for users when a thumbnail can be shown before the
actual file is finished downloading.
XMPP already has a protocol for specifying thumbails, [Jingle Content Thumbnails](https://xmpp.org/extensions/xep-0264.html).
However, this protocol requires that the thumbnail is a base64-encoded image published using
[Bits of Binary](https://xmpp.org/extensions/xep-0231.html). This prevents clients from implementing newer technologies, such as
[Blurhash](https://github.com/woltapp/blurhash).
This document specifies are more general and extensible element for specifiying thumbnails.
## Usage
```
LEHV6nWB2yk8pyoJadR*.7kCMdnj
```
In this example, the thumbnail is specified of type `blurhash`, which means that a supporting
client should decode the `` element using the [Blurhash](https://github.com/woltapp/blurhash) algorithm.
In order to enable a sort-of interoperability with [Jingle Content Thumbnails](https://xmpp.org/extensions/xep-0264.html), a type
`urn:xmpp:thumbs:0` is defined. If this is specified, then a supporting client must
interpret the child of the `` as an `` element as specified by
:[Jingle Content Thumbnails](https://xmpp.org/extensions/xep-0264.html)
```
```
In the case of [Jingle Content Thumbnails](https://xmpp.org/extensions/xep-0264.html) compatibility,
the `` element must contain exactly one `` element.
Other extensions may define similar types. Note that the content of the `` element
is dependent on the type specified in the ``
element.
### Thumbnail Types
#### Blurhash
If a sender specifies the type to be of `blurhash`, then the payload must contain the
image data as specified by the [Blurhash](https://github.com/woltapp/blurhash) algorithm. Care should be taken to prevent
the blurhash data from growing to large in order to prevent hitting the stanza size limit.
## Usage with Stateless Inline Media Sharing
NOTE: This example is taken from [Stateless Inline Media Sharing](https://xmpp.org/extensions/xep-0385.html) and modified for this protocol.
```
Look at the nice view from the summit.
image/jpeg
summit.jpg
3032449
2XarmwTlNxDAMkvymloX3S5+VbylNrJt/l5QyPa+YoU=
2AfMGH8O7UNPTvUVAM9aK13mpCY=
Photo from the summit.
LEHV6nWB2yk8pyoJadR*.7kCMdnj
```
## Security Considerations
The same considerations apply as specified by [Jingle Content Thumbnails](https://xmpp.org/extensions/xep-0264.html).