Mastodon ‘Failed to Fetch’ on Federated Timeline: Fix Steps

When you open the Federated timeline in Mastodon and see a persistent Failed to fetch error, your client cannot reach the remote servers that host posts from other instances. This error typically appears because your instance blocks outbound connections to certain remote servers, or because those servers have rate-limited or blocked your instance in return. In this article, you will learn the exact causes of this error and the step-by-step fixes that restore your Federated timeline.

Why the Federated Timeline Fails to Fetch Remote Posts

Mastodon instances communicate with each other using the ActivityPub protocol. When you open the Federated timeline, your instance sends a request to every remote server whose posts it has previously stored or that are mentioned in local posts. If any of those remote servers are unreachable, the entire timeline request can fail.

The root cause is almost always one of three things:

Outbound Connection Blocked by Your Instance

Instance administrators can block entire domains at the server level. If a remote server is blocked, your instance will not send any requests to it. The client then shows Failed to fetch because the timeline data from that server never arrives.

Remote Server Rate Limiting or Blocking Your Instance

Large instances sometimes rate-limit or block smaller instances that send too many requests. If your instance is on a remote server’s blocklist, that server will refuse connections. The timeline fetch fails for posts from that specific server.

Stuck Background Jobs in Sidekiq

Mastodon uses Sidekiq to process background tasks such as fetching remote posts. If a job gets stuck or repeatedly fails, Sidekiq will queue retries. When the retry queue fills up, new fetch jobs cannot start, and the Federated timeline stops loading.

Steps to Clear the Failed to Fetch Error on the Federated Timeline

Follow these steps in order. Each step resolves a specific cause. Test the Federated timeline after each step to see if the error clears.

Step 1: Check Domain Blocks on Your Instance

1. Open the Administration panel
   Log in to your Mastodon account as an administrator. Click Preferences in the top-right menu, then select Administration from the sidebar.
2. Navigate to Federation > Domain blocks
   In the Administration section, click Federation, then Domain blocks. You will see a list of all domains that your instance blocks.
3. Remove any block that affects the Federated timeline
   If you see a domain that corresponds to a server whose posts you want to see, click the Delete button next to that domain. Confirm the removal. The instance will now allow outbound connections to that server.

Step 2: Clear Stuck Sidekiq Jobs

1. Open the Sidekiq dashboard
   Go to https://your-instance.example.com/sidekiq. You may need to log in with your admin credentials.
2. Click the Retries tab
   In the Sidekiq dashboard, click Retries. This shows all background jobs that have failed and are waiting to be retried.
3. Delete or retry stuck jobs
   If you see many retries related to fetching remote posts, select all of them by clicking the checkbox at the top of the list. Then click the Delete button to remove them. Alternatively, click Retry to force a single retry attempt.
4. Restart Sidekiq if needed
   If the retry queue is empty but the error persists, restart Sidekiq from the command line: sudo systemctl restart mastodon-sidekiq. This clears any stuck processes.

Step 3: Check Your Account Filters

1. Open your account preferences
   Click Preferences in the top-right menu.
2. Navigate to Filters
   In the sidebar, click Filters. You will see any custom filters you have created.
3. Review filters that apply to the Federated timeline
   If a filter is set to hide all posts from a specific server, it can cause the Federated timeline to fail to load. Edit or delete any filter that targets remote servers.

Step 4: Test with a Different Client or Browser

1. Open the Mastodon web interface in a private browser window
   Use a browser that you have not used before for Mastodon. This rules out local cache or extension issues.
2. Log in and open the Federated timeline
   If the timeline loads correctly in the private window, clear your regular browser cache and cookies for your instance domain.

Step 5: Contact Your Instance Administrator

1. Send a direct message to your admin
   If you are not an administrator, send a direct message to the instance admin explaining that the Federated timeline shows Failed to fetch. Include the exact error message and the time it started.
2. Ask them to check the server logs
   Administrators can look at the Mastodon logs at /var/log/mastodon/ or through journalctl: sudo journalctl -u mastodon-web -f. The logs will show which remote server caused the failure.

If the Federated Timeline Still Fails After the Main Fix

Federated Timeline Loads Slowly Then Shows Failed to Fetch

This usually means your instance is trying to contact a remote server that is online but slow to respond. The Mastodon client times out before the server replies. The fix is to increase the timeout value in the Mastodon configuration. Edit the .env.production file and add or modify the line STREAMING_API_TIMEOUT=30. Restart the web service with sudo systemctl restart mastodon-web.

Federated Timeline Works for Some Users But Not Others

If only certain users see the error, the cause is likely a per-user filter or a browser extension. Ask the affected user to disable all browser extensions and test in a private window. If the error disappears, re-enable extensions one by one to find the culprit.

Federated Timeline Shows Failed to Fetch After an Instance Update

After upgrading Mastodon, background migration tasks may run for hours. During this time, the Federated timeline may fail to fetch new posts. Check the Sidekiq dashboard for a large number of scheduled jobs. Wait for the migrations to finish, or contact your admin to check the migration status.

Item	Local Timeline	Federated Timeline
Data source	Only posts from users on your instance	Posts from all known remote instances
Common failure cause	Local server down or database error	Remote server unreachable or blocked
Fix method	Restart Mastodon services or repair database	Remove domain block or clear Sidekiq retries
Load time	Fast, because only local data is fetched	Slower, because many remote requests are made

The Federated timeline error Failed to fetch is almost always caused by a blocked domain, a stuck Sidekiq job, or a per-user filter. By following the steps in this article, you can identify and remove the blocking factor. After clearing the error, you may want to check the Administration > Federation > Instances page to see which remote servers your instance is currently connected to. As an advanced tip, you can use the Mastodon API endpoint /api/v1/timelines/public with the local=false parameter to test the Federated timeline directly from the command line using curl.