> ## 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.

# Uploads & Media

> Payload limits, upload-from-url, video, and cancel-in-flight behaviour

## Body size limit

The Postiz backend accepts JSON bodies up to **50 MB** on the post-creation
routes (`POST /public/v1/posts` for the public API, plus the internal
`/posts` and `/copilot/*` endpoints used by the web UI). Other endpoints
fall back to the framework default and are much smaller — don't inline
base64-encoded images in arbitrary endpoints.

## Accepted MIME types (Public API)

The `/public/v1/upload` and `/public/v1/upload-from-url` endpoints validate
the uploaded file's detected MIME type against this allowlist:

| Type      | MIME         |
| --------- | ------------ |
| JPEG      | `image/jpeg` |
| PNG       | `image/png`  |
| GIF       | `image/gif`  |
| WebP      | `image/webp` |
| AVIF      | `image/avif` |
| BMP       | `image/bmp`  |
| TIFF      | `image/tiff` |
| MP4 video | `video/mp4`  |

PDFs are **not** accepted by the public API. The only PDF flow Postiz
supports is LinkedIn document carousels, which are produced internally
by converting an image carousel to PDF — you can't post a PDF directly
through the public API.

## "PayloadTooLargeError" when creating a post

You sent a request body larger than 50 MB to `POST /public/v1/posts` —
almost always because you inlined image data instead of uploading first.

**Fix:** upload media via `/public/v1/upload` (or `/public/v1/upload-from-url`),
then reference the returned `id` and `path` in the post body's
`image` array.

```bash theme={null}
# Step 1: upload the file
curl -X POST "https://api.postiz.com/public/v1/upload" \
  -H "Authorization: your-api-key" \
  -F "file=@photo.jpg"

# Step 2: pass id + path into the post
```

## `upload-from-url` timeouts or "fetch failed"

`/upload-from-url` proxies the source URL through the Postiz backend.
If the source server is slow, unreachable, blocks Postiz's user agent,
or sits behind authentication, the upload fails.

**Fix**

* Make sure the source URL is publicly reachable HTTPS, with no auth.
* Don't link to private S3 URLs, signed URLs that have expired, or
  intranet hosts.
* If the source is consistently slow, pre-download the file locally and
  use the multipart `/upload` endpoint instead.

## "Failed to load video metadata"

Postiz inspects uploaded videos for duration, dimensions, and codec
before passing them to the social provider. Files outside the supported
range fail here.

**Recommended video format**

* Container: MP4
* Video codec: H.264 (baseline or main profile)
* Audio codec: AAC
* Frame rate: 30 fps or less
* Resolution: ≤ 1920×1080 for most providers; TikTok and YouTube
  Shorts prefer portrait 1080×1920.

Other formats may upload but get rejected by the social provider
downstream.

## "uploader plugin does not allow removing files during an upload"

You hit Cancel on a file that was already being uploaded. Postiz's
uploader doesn't support mid-flight cancellation — wait for the upload
to complete, then delete the asset from the post.

This is a known UX limitation; see [Known Issues](/troubleshooting/known-issues).