workflow · how to
Choose media for a post
Follow the choose media for a post workflow in Slack.
Goal
Attach the right image or video while you compose a post in Slack. You can upload a file, paste a direct link, pick from your Asset Library, or select reference assets when the modal offers them.
When to use this
Use Choose media whenever your selected format requires or accepts media and you need to add, change, or replace the visual for the current draft. Common cases include:
- Starting a reel, carousel, or image post that needs at least one file
- Swapping creative after a first pick did not fit the caption or platform
- Reusing approved assets already stored in the library instead of uploading again
- Attaching brand or campaign reference assets when those picks are available
You open Choose media from inside the Create modal. It is not a standalone entry point from App Home.
Before you begin
Confirm these items before you open the media picker:
- You have access to the Create work center for your active brand
- The Create or compose modal is already open for a format that requires or accepts media
- You know which source you want: upload, link, library, or reference assets
Asset Library browsing requires the Content library feature, which is included on Starter, Team, and Scale plans. On the Free plan, use upload or link sources, or add assets through Manage the Asset Library after upgrading.
Canva design imports are available on all plans (Free, Starter, Team, and Scale) when you bring approved creative into a post through the import workflow.
Steps
1. Open Choose Media from Create
- In the Create modal, choose Choose media (or open the media section for your selected format).
- The Choose Media modal opens on top of Create. Your draft context stays attached so you can return without losing work.
2. Pick a media source
Select one source path. You can change sources later, but switching away from an in-progress AI media path triggers a confirmation step.
| Source | When to use it |
|---|---|
| Upload a file | You have the file on your device. Files up to 10 MB can upload in this modal. Larger files belong in the Asset Library. |
| Enter a URL | You have a direct link to an image or video. The link updates the draft and clears conflicting fields from other sources. |
| Asset Library | You want to search, filter, and select one or more assets already stored for the brand. |
| Reference assets | The modal offers brand or campaign reference picks you want to attach. |
If you started on an AI generate path and select a different source, Slack asks you to Continue or Cancel the switch. Continue moves to the new source. Cancel keeps you on the current path.
3. Complete your selection
Upload path
- Choose Upload a file and select the file from your device.
- Wait for ingest to finish. Oversize files, download failures, and unreadable files show inline errors in the modal.
Link path
- Choose Enter a URL and paste a direct media link.
- Submit or confirm the link. Invalid links show inline validation before you return to Create.
Asset Library path
- Choose Asset Library to open the asset picker.
- Search or filter the list, then select one or more assets.
- Use Next when you are ready to confirm the selection.
Reference assets path
- When offered, open the reference picker and select brand or campaign reference assets.
- Remove individual reference assets with the remove action if you change your mind before submit.
4. Submit back to Create
- Review the selection summary in Choose Media.
- Submit to merge media into the parent Create modal.
- Fix any inline validation errors before you submit again. Common issues: missing file, invalid link, no assets selected, or archived assets.
5. If generation or rendering is still running
When media depends on a render or generation job, the modal shows status instead of a finished preview. Use the status actions to go back, retry, or return to Create without losing draft state. You can also wait for the result and reopen Choose media when the job completes.
Success criteria
You finished this workflow when:
- The Create modal shows the selected media source and asset count
- Preview reflects the attached assets before you save or submit for review
- Validation errors are cleared and submit succeeds
- The draft moves forward as draft saved, queued, or pending approval once you complete the rest of Create
If generation fails, the item may land in generation failed. Retry from Create or see Retry a failed generation.
Troubleshooting
| Symptom | What to check | What to do |
|---|---|---|
| Choose media is missing | Format may be text-only | Pick a media-capable format in Create first |
| Upload rejected as too large | 10 MB limit in this modal | Upload through the Asset Library for larger files |
| Link does not attach | URL is not a direct media link | Use a direct file URL or switch to upload |
| Library picker is empty or blocked | Plan or brand scope | Confirm Content library on Starter or above, or use upload or link |
| Archived asset error | Asset was archived | Pick a different library asset or restore it in the library workflow |
| Switch confirmation appeared | You left an AI generate path | Choose Continue to switch sources or Cancel to stay |
| Preview missing after submit | Render or generation still running | Use wait actions, retry, or return to Create and check status |
| Save blocked for missing media | Format requires media | See Media is required before saving or previewing |