Mastodon server administrators often see tags appear in the Trending sidebar that do not match the community guidelines or the instance theme. Without an approval workflow, any tag that gains enough local activity can automatically trend. This can lead to spam tags, off-topic content, or hashtags that violate the server rules showing up prominently. This article explains the built-in approval system, how to enable it, and how to review and manage trending tags step by step.
Key Takeaways: Mastodon Trending Tags Moderation Workflow
- Administration > Server Settings > Trends > Tags: Enable tag review requiring admin approval before any tag appears in the trending list.
- Moderation > Trends > Tags: Review pending tags and approve, reject, or silence them individually.
- Moderation > Trends > Trending Tags: View and manage already approved tags and remove or silence any tag at any time.
Understanding the Trending Tags Approval Feature
Mastodon includes a moderation feature that lets server administrators control which tags appear in the Trending section. By default, any tag that reaches a certain activity threshold on the local timeline is automatically shown to users. This can be a problem when a tag is relevant for only a short time or when it promotes content outside the server focus.
The approval workflow changes this behavior. When enabled, no tag trends until an admin reviews and approves it. The system also allows admins to silence a tag so it stops trending without removing it from posts entirely. This feature is built into the Mastodon web interface and does not require any code changes or third-party tools.
Prerequisites for Using the Approval Workflow
You need an admin account on a Mastodon server running version 3.5 or later. The Trends feature must be active on the instance. You also need access to the Administration panel. If you do not see Moderation > Trends in the sidebar, your account may not have the correct permissions. Contact your instance owner or check your role settings.
Steps to Enable and Manage Trending Tag Approval
Follow these steps to turn on the approval requirement and then review pending tags.
- Open the Administration panel
Click the hamburger menu in the top-left corner. Click Preferences. Then click Administration in the left navigation. This opens the server settings area. - Navigate to Server Settings > Trends
In the Administration menu, click Server Settings. Then click Trends in the submenu. This page controls how trending content works on your instance. - Enable tag review
Under the Tags section, find the option labeled Require review before allowing a tag to trend. Toggle this switch to the on position. A green checkmark confirms the change is saved. - Go to Moderation > Trends > Tags
Click Moderation in the main left menu. Then click Trends and select Tags. This page lists all tags that are pending review. You see the tag name, the number of posts using it, and a preview of recent posts. - Approve or reject each tag
For each pending tag, click Approve to allow it to trend. Click Reject to block it from trending. Click Silence to stop the tag from trending but keep it searchable and usable in posts. The tag disappears from the pending list after you take action. - Manage already approved tags
Click Trending Tags under Moderation > Trends. This shows all tags currently approved and trending. You can click Silence or Remove to stop any tag from appearing in the trending sidebar.
Common Mistakes and Things to Avoid
Tags Still Appear Without Approval
If tags continue to show in the Trending section after you enabled review, check that you saved the toggle. The change takes effect immediately but only applies to new tags. Tags that were already trending before you enabled review remain visible. You must manually remove them from Moderation > Trends > Trending Tags.
Accidentally Silencing a Tag That Should Trend
Silencing a tag removes it from the trending list but does not delete the hashtag from posts. If you silence a tag by mistake, go to Moderation > Trends > Trending Tags and click the Approve button next to that tag to restore it. Tags that are rejected cannot be approved again unless they reappear in the pending list.
Missing the Pending Tags List
The pending tags list only shows tags that have reached the activity threshold. If your server has low activity, no tags may appear for review. You can check the local timeline for popular hashtags and manually add them to the trending list by approving them from the Trends > Tags page. If a tag does not appear, it has not met the activity requirement.
Trending Tags Approval Workflow vs Automatic Trending
| Item | Approval Workflow | Automatic Trending |
|---|---|---|
| Tag visibility | Only approved tags appear in Trending | Any tag meeting activity threshold appears |
| Admin effort | Requires manual review of each tag | No admin action needed |
| Control level | Full control over trending content | No control unless you manually silence tags |
| Spam protection | High — admins catch unwanted tags before they trend | Low — spam tags can trend immediately |
| Setup time | Less than one minute to enable | No setup required |
Use the approval workflow when you want to curate trending content to match your server theme. Use automatic trending when you trust the community and want minimal moderation overhead.
You can now enable the trending tags approval workflow and review pending tags from the Moderation panel. Check the pending list at least once per day to keep the Trending section relevant. For advanced control, consider setting up custom moderation filters that automatically silence tags containing specific keywords before they reach the pending list.