How to Set Trending Hashtag Approval Workflow on a Mastodon Instance

Mastodon instance moderators often want to control which hashtags appear on the trending page. Without an approval workflow, any hashtag that reaches the trending threshold appears automatically. This can lead to spam, irrelevant tags, or content that does not match the instance culture.

Mastodon includes a built-in approval system for trending hashtags that lets moderators review and approve each tag before it becomes visible to users. The workflow uses a review queue where pending hashtags are listed, and moderators can approve or reject them individually.

This article explains how to enable the trending hashtag approval workflow on a Mastodon instance. It covers the required server settings, the moderator review interface, and common configuration mistakes to avoid.

What Is the Trending Hashtag Approval Workflow?

The trending hashtag approval workflow is a moderation feature that prevents hashtags from appearing on the trending page until a moderator reviews them. By default, Mastodon instances with trends enabled show any hashtag that reaches a certain usage threshold. This automatic behavior can result in trending tags that are off-topic, promotional, or abusive.

When the approval workflow is turned on, hashtags that meet the trending threshold are placed into a pending review queue instead of being published immediately. Moderators see these pending tags in the moderation interface and can approve or reject each one. Rejected tags never appear on the trending page. Approved tags are published and remain visible until they expire or are removed manually.

The approval workflow is a server-level setting. It applies to all hashtags across the instance. Individual users cannot opt in or out of this workflow. Only moderators with the appropriate permissions can review and approve tags.

Prerequisites for Enabling the Workflow

Before you enable the approval workflow, make sure your instance meets these requirements:

• You must have administrator or moderator access to the Mastodon server.
• Trends must be enabled on the instance. Go to Administration > Server Settings > Trends and confirm that the Enable trends toggle is turned on.
• The instance must be running Mastodon version 3.5 or later. Older versions do not include the approval workflow feature.

Steps to Enable the Trending Hashtag Approval Workflow

Follow these steps to turn on the approval workflow for trending hashtags on your Mastodon instance. All steps are performed in the web-based moderation interface.

1. Log in as an administrator or moderator
   Open your Mastodon instance in a browser. Enter your credentials for an account that has the admin or moderator role. Only accounts with the correct permissions can access the server settings.
2. Open the Server Settings page
   Click the gear icon in the top navigation bar. From the dropdown menu, select Administration. Then click Server Settings in the left sidebar.
3. Navigate to the Trends section
   In the Server Settings page, scroll down or use the left sidebar to find the Trends section. Click on it to expand the trend-related settings.
4. Enable the Require review option
   Locate the Require review toggle. Click the toggle to switch it to the on position. The toggle changes color from gray to blue when enabled. A confirmation message appears at the top of the page saying that the setting has been saved.
5. Save the settings
   Click the Save changes button at the bottom of the Trends section. The approval workflow is now active. New hashtags that reach the trending threshold will be placed into the pending review queue instead of appearing automatically.

How Moderators Review and Approve Trending Hashtags

Once the approval workflow is enabled, moderators must review pending hashtags regularly. The review process is straightforward and does not require leaving the moderation interface.

1. Open the Moderation panel
   Click the gear icon and select Moderation from the dropdown menu. Alternatively, go directly to the URL https://your-instance.example.com/admin/trends/hashtags.
2. Go to the Trends section
   In the left sidebar under Moderation, click Trends. Then click Hashtags to see the full list of trending and pending hashtags.
3. View the Pending review tab
   Above the hashtag list, there are three tabs: Pending review, Approved, and Rejected. Click Pending review to see only hashtags that need your decision.
4. Approve or reject each hashtag
   For each pending hashtag, click the Approve button to allow it to appear on the trending page. Click the Reject button to block it. Rejected hashtags are moved to the Rejected tab and will not appear in trends.
5. Review approved hashtags periodically
   Switch to the Approved tab to see all hashtags that are currently trending. You can remove any hashtag from the trending page by clicking the Remove from trends button next to it.

Common Configuration Mistakes to Avoid

Trends Not Enabled on the Instance

The approval workflow only takes effect when trends are enabled. If you toggle the Require review option but trends are turned off, no hashtags will be collected for review. Check Administration > Server Settings > Trends and confirm that the Enable trends toggle is on.

Moderator Lacks Permission to Review Trends

Not all moderator roles can access the Trends section in the moderation panel. If a moderator cannot see the Pending review tab, an administrator must assign the correct role. Go to Administration > Users, find the moderator account, and assign the Admin role or a custom role that includes the trends:manage permission.

Pending Hashtags Accumulate Without Review

When the approval workflow is enabled, hashtags stay in the pending queue indefinitely until a moderator acts on them. If no one reviews the queue, trending tags will stop updating entirely. Assign a schedule for at least one moderator to check the pending queue daily. You can also set up email notifications for pending trends in Administration > Server Settings > Notifications.

Accidentally Rejecting a Hashtag That Should Be Approved

If a moderator rejects a hashtag by mistake, the tag can be restored. Go to the Rejected tab, find the hashtag, and click Approve. The hashtag moves to the Approved tab and appears on the trending page immediately.

Mastodon Trending Hashtag Approval Workflow: Settings Overview

Item	Setting Disabled	Setting Enabled
Trend visibility	Hashtags appear automatically when threshold is met	Hashtags are hidden until a moderator approves them
Moderator workload	No review needed	Moderator must review each tag
Risk of unwanted tags	Higher — spam and off-topic tags can trend	Lower — moderator filters out unwanted content
Trending page freshness	Updates automatically	Updates only after moderator review

You can now set up the trending hashtag approval workflow on your Mastodon instance. After enabling the Require review option, assign at least one moderator to check the pending queue daily. For large instances, consider creating a dedicated moderation team for trends. To further refine content moderation, explore the keyword filtering options under Administration > Server Settings > Content retention.