Move topics from one Discourse instance to another

Need to move some stuff from one instance of Discourse to another?

There is a command line tool to export a topic, a set of topics, or an entire category, and another to import them in at the other end.

Topic Export/Import

  • one or more topics and their replies
  • the users who posted in the topic

Category Export/Import

  • the category and all its subcategories
  • its security settings
  • custom groups mentioned in the security settings
    • :warning: if any of the groups have ‘membership requests’ enabled, it will crash. Turn this off before the export
  • all topics and posts in the category and subcategories
  • all users who posted, and assigns them to the groups

Begin: Identify the IDs

First, identify the ID(s) of the =Export= that you wish to export. You’ll find this at the end of the URL used to access it.


    (in this case you are in the middle of a topic - grab the first number)


Category or Topic ID(s)

Multiple topics

You can select more than one topic by adding IDs separated by a space; this works in the field above (I don’t think that this works for categories though):

  • 53797 200943 124096

Run the Export Script

The tool can be run as a root user inside the container:

cd /var/discourse
./launcher enter app

Run this command:

discourse export_=Export= =ID=

The output should look something like this:

Starting export of =Export=…

Where are the new users all coming from?
Export saved to =Export=-export-2021-08-27-015437.json


Move the Exported File

The exported .json file needs to be moved from the inside of the application container where you did the export to the inside of the container of the receiving instance. This takes a few steps.

Copy it to the ‘outside’

Exit the container if you haven’t already


You should now have a prompt like this:


Use docker to copy the file out of the container (you can’t move it I don’t think)

docker cp app:/var/www/discourse/=FileName= .

Move it to the other instance

This is beyond the scope of this guide, but this might help you get there:

Copy it into the container in the receiving instance

SSH into your receiving instance as root and get to the Discourse directory:

cd /var/discourse

Use docker once again to copy the file into the other container

docker cp =FileName= app:/var/www/discourse

Import the Content

Enter the container in the receiving instance:

./launcher enter app

Run the import script

discourse import_=Export= =FileName=

:cake: Done!

You might need to tidy up some loose ends, but hopefully, it should all be done.

Advanced Tips

Missing Ruby Gem

When doing a complex category import, my instance was missing the ‘Listen’ Ruby.
This was solved by doing this: (using the Discourse user inside the container)

./launcher enter app
su discourse
bundle config --delete without
bundle config --delete with
bundle install

This broke the rails console, necessitating a rebuild afterwards

./launcher rebuild app


In a multisite environment, use the RAILS_DB env variable.

RAILS_DB=xxxmoves discourse export_=Export= =ID=
RAILS_DB=dancerehab discourse discourse import_=Export= =FileName=

Please report bugs in the bug category, and request enhancements in the feature category.

Related Topics

Last Reviewed by @SaraDev on 2022-07-13T00:00:00Z

Last edited by @hugh 2024-05-29T06:25:11Z

Check documentPerform check on document:

I’m about to have a crack at this again.

Is there an easy way to migrate the relevant uploads along with the Topics?

Not really. A thing that mostly works is if you get all of those uploads and paste the URL of the original in to any post on the site you’re moving to, then what should happen is that those uploads will get created with the same SHA and it Just Works.

So you’d do the thing that converts the stuff in the post to the URL to get those URLs. (I can never quite remember how to do that, so I have to figure it out every time).

Hmmm - I remain a bit confused by that. Are you saying that this will work?

  1. Grab all of the upload files from the first site
    • how?
  2. Drop them into a single topic
  3. They will generate the same relative link as they had in the old site and magic!

Or did you mean this?

  1. Grab all of the absolute URLs in your categories of interest from the old site
  2. Paste these into a Topic
  3. They will all be downloaded to the new site with the same SHA and the existing links will all work like magic

Or something else entirely?

I think either of those should work. However you can get those images to the new site, they should generate the same sha so that will magically make the existing links in the topics work.

Maybe you could do something like

Topic.where(category_id: cat_id).each do| t|
  Post.where(topic_id: do |p|
      p.cooked.match(image url)....
         puts(the match) 

And I think if you do that and paste those links into a post anywhere on your site it should download all of those images to local and make the same sha, so then those links. You can try a couple by hand to see.

It’s the middle of the night. Your mileage may vary.

1 Like

Hello, I’m not sure if this tutorial is what I want to do, but raise the question here.

If I install discourse on a server, but due to growth I need to migrate to a more powerful one, are these the steps?

What happens, for example, with the backup option? Can’t I do it, install Discourse on another server and then restore the backup copy of the other instance from that option?

I await your clarification, since I want to know how to migrate when I need to and not lose the work I have been doing recently.

No. To move to a bigger server a simple backup and restore is all that’s needed. You can also Move a Discourse site to another VPS with rsync