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

# Images and video

> Adding media, alt text, video thumbnails, size limits and the design editor

**Where:** Inside the composer, the attachments bar under the editor

## Four ways to add media

* **Drag and drop** a file onto the editor.
* **Paste** an image straight from the clipboard.
* **Insert Media** opens your [media library](/general/media-library).
* **Import** pulls media from a connected third-party service such as HeyGen,
  see [Third-party integrations](/general/automations/third-party).

Plus two that generate it: **AI Image** and **AI Video**, covered in
[AI generation](/general/composer/ai-and-imports).

## Limits and formats

|          | Limit                                      |
| -------- | ------------------------------------------ |
| Image    | 10 MB each                                 |
| Video    | 1 GB each                                  |
| Accepted | JPEG, PNG, GIF, WebP, AVIF, BMP, TIFF, MP4 |

<Note>
  Postiz detects the real type from the file contents, not the extension.
  Renaming a `.mov` to `.mp4` will not get it accepted.
</Note>

Platform rules are stricter than these and vary a lot: YouTube wants exactly
one video, Pinterest allows at most five images, Google Business takes no video
at all. See [Posting rules by platform](/general/platforms/overview).

## Reordering and removing

Thumbnails in the attachments bar are draggable, so the order you see is the
order the platform gets. The order matters for carousels and for platforms that
treat the first image as the cover.

## Media settings

Clicking a thumbnail opens its settings:

* **Alt text.** Worth writing. It is the accessibility floor on every platform
  that supports it, and several platforms surface it in search.
* **Video thumbnail.** Pick the frame used as the cover, either by scrubbing to
  a timestamp or choosing a frame. Platforms that require a separate cover
  image, Pinterest video pins for example, use this.

## The design editor

**Design Media** opens a full editor inside Postiz where you can build a visual
from templates, text and your own assets, then use it in the post without
exporting and re-uploading.

<Note>
  **Availability:** included on paid Postiz Cloud plans. On self-hosted installs
  the design editor needs a Polotno key configured by whoever runs the instance,
  see [Image and video editing](/self-host/configuration/polotno).
</Note>

## Uploads that fail

<AccordionGroup>
  <Accordion title="The file is rejected as the wrong type">
    The detected type is not in the accepted list. Convert it, most often an
    unusual video container that needs re-encoding to MP4.
  </Accordion>

  <Accordion title="A large video stalls">
    Video uploads are capped at 1 GB per session. Compress before uploading:
    the platform will re-encode anyway, so a smaller source rarely costs
    visible quality.
  </Accordion>

  <Accordion title="The post fails even though the upload worked">
    The media is fine but breaks a platform rule, wrong count, wrong type, or
    a missing cover. Check
    [Posting rules by platform](/general/platforms/overview).
  </Accordion>
</AccordionGroup>