Change a topic's settings

What you'll achieve

Updated settings on an existing topic — for example how long data is kept before it is cleaned up.

Before you start

• Your role badge says Developer or higher, and the environment allows changes — in a read-only environment only admins can edit.
• Know that the number of partitions cannot be changed after a topic is created — it's shown read-only on the edit form.

Steps

1. Click Topics in the sidebar and find your topic in the list.
2. Click the pencil icon in the Actions column (hover text: "Edit topic"). You can also open the topic, go to the Settings tab, and click Edit there.
3. Change what you need. The everyday settings are on the form directly — for example retention.ms (how long messages are kept, in milliseconds) and cleanup.policy (how old messages are removed). Everything more exotic is behind the Expert mode button — leave it alone unless you were given specific values. (What the settings mean: Topics guide.)
4. Click Save Changes.

What success looks like

A green confirmation appears: "Changes saved successfully". The form also notes that "Configuration changes may not be reflected immediately" — give it a moment before checking the Settings tab.

Something went wrong?

• The pencil icon is greyed out with "Editing is disabled for this environment" — the environment is read-only or your role is Viewer. Ask your team's admin.
• "No changes detected" — you clicked Save without changing anything; nothing was sent.
• An error message appears after saving — read it; if it doesn't help, contact the platform team.

Background on what each setting does? Read the Topics guide.