How to Use the Slack Channel User Extractor

*Performance may slow down to ~1 second per profile when scrape Custom Fields is enabled (Step 3).

Before you start

• Workspace access: You must be a member of the Slack workspace you want to extract users from.
• Have the channel names (e.g. #general, #sales-team) ready, or prepare a Google Sheet/CSV file with one channel per row (publicly accessible link required).

Step 1: Connect your Slack account

To let the Phantom act on your behalf:

1. Install the PhantomBuster browser extension and connect your Slack session in one click.
2. If you’re not using Chrome or Firefox, you can retrieve your session cookie manually (see our cookie guide).
3. You’ll also need to provide your Slack workspace URL

Step 2: Provide the channels to extract

You can give your input in one of the following ways:

1. A channel name:
   • Enter a single Slack channel name in the input field (e.g., #marketing).
2. A URL:
   • Paste the URL of a Google Sheet with your Slack channel names, one per row (make sure it’s shared with “Anyone with the link”).
   • Or upload a CSV file with your Slack channel names (make sure it’s publicly accessible, and note that CSV upload is only available on paid plans).

→ If you’re using a spreadsheet, the Phantom defaults to the first column (A). To use a different column, enter the column’s header name in the field “Name of column containing Slack channels.”

Step 3: Configure extraction options

1. Number of channels to process per launch, 20 at most (optional):
   • Default = empty, the Phantom processes up to 20 (defaults to all).
2. Number of users to scrape per channel (optional):
   • Default = empty, the Phantom retrieves all users in each channel.

Advanced settings (dropdown in setup)

1. Scrape all channels (optional):
   • Enable to re-extract even if channels were already processed in past runs.
2. Scrape custom fields (optional):
   • Enable to collect workspace-specific profile fields (e.g. department, role). This may slow down processing.

Result file settings (dropdown in setup)

1. Name your results file (optional)

   • You can customize the file name.

     If you rename the file between launches, the Phantom will create a new results file and start processing inputs from scratch.

2. Fields to keep (optional)
   • Export only the fields you care about by listing them (comma-separated).
     Example: profileUrl, job, location.
   • This generates a second CSV file with just those fields.
   • Learn more in our guide: Customize how your Phantom results files are saved.

Step 4: Select launch frequency

Choose how often the Phantom should run:

1. Launch manually: Start the Phantom yourself whenever you need.
2. Launch once at a specific time: schedule a one-time run at a set date and time.
3. Launch repeatedly: schedule regular runs (e.g. once per day, several times during working hours).
4. Launch after another Phantom: chain automations together so this Phantom starts right after another finishes.
5. Advanced scheduling: customize the exact minutes, hours, days, or months when the Phantom should run.

→ For a complete walkthrough of scheduling options, see our guide to scheduling Phantoms automatically.

Step 5 (Optional): Advanced settings

Advanced settings are available if you want to fine-tune how your Phantom runs, but by default they’re already optimized for most use cases.

We recommend leaving them as they are unless a guide specifically instructs you to change something.

→ For a detailed overview of all advanced options (like execution limits, retries, email notifications, proxies, webhooks, and file management), see our Advanced settings guide.

Launch and results

When you’re ready:

1. Click Launch to start your Phantom.
2. Once it finishes, open the Results tab in the Phantom console to see channel → member rows (user ID, display name, email if public, title, and any chosen custom fields).
3. Download your results as a CSV or JSON file.

→ To learn how to export your data to Google Sheets, integrate with other tools, or reuse it in more automations, check our Access and Export your Phantom Results guide.

Export and input limits on the Free plan
If you’re on the Free plan or Free trial, some features are limited:
- CSV exports include only the first 10 rows of results.
- CSV download links (for dynamic viewing in Google Sheets or integrations) are not available.
- JSON exports are not available.
- CSV upload as an input method is not supported.
To unlock all features, you’ll need to upgrade to a paid plan.

What you give (Input) and What you get (Output)

This section gives you a detailed breakdown of everything you need to provide to run this Phantom, and everything you’ll receive once it completes.

What you give (Input)

What you get (Output)

Tips and troubleshooting

Common pitfalls

• Using a private spreadsheet (make sure it’s set to “Anyone with the link”).
• Private channels: Extraction works only for channels you can access (you must be a member). Direct messages and group DMs are not supported.

If you run into issues

• Check how to troubleshoot your phantom using Logs.
• Browse the Fix Issues & Troubleshoot Errors section for solutions to common problems.
• Review our Automation Rate Limits by Platform guide.
• Check our Best Practices for Social Media Automation guide.

Suggested automations

• Slack Message Sender → Use the extracted member IDs as input to send personalized messages.
• Slack Search Export → Cross-check active users in specific conversations with your extracted member lists.