Prepare images and video

Upload media in the composer or select an existing inspected asset from the workspace library. BlendDuck records the file type, dimensions, size, duration, and processing state before a provider receives it.

Before uploading

• Use the original high-quality file and keep a local source copy.
• Prefer common web formats such as JPEG/PNG for images and MP4 for video unless the target provider documents another requirement.
• Remove embedded credentials, private filenames, and unnecessary metadata.
• Confirm that you have rights to publish the asset on every selected channel.

Provider limits change by account, post type, and placement. The composer's target-specific validation is the current source of truth for aspect ratio, resolution, duration, file size, and item count.

Add the asset

1. Open the composer and choose Media.
2. Upload a file or choose one from the workspace library.
3. Wait for inspection and preview generation to finish.
4. Add alt text where the provider supports it.
5. For video, review the thumbnail frame and duration.
6. Open every channel variation and remove or replace unsupported media.

An asset can be shared by multiple targets while each target keeps its own ordering and provider settings.

Accessible media

Write alt text that describes the meaningful visual information, not the file name. Avoid repeating the full caption. Captions or subtitles are recommended for spoken video; verify them in the native preview when a provider generates its own version.

Fix a rejected upload

• Unsupported type: export to a provider-supported format.
• File too large: re-encode while preserving legibility and required dimensions.
• Wrong aspect ratio or duration: create a target-specific variation.
• Processing failed: retry the original once, then re-export the source if the failure repeats.
• Remote URL unavailable: use a stable public HTTPS asset or upload it to the BlendDuck library instead of a short-lived link.

Changing media is an editorial change and requires a new approval when the workspace uses content approvals.