7 October 2026, 02:25 PM
I’m getting ready for a Slack to Teams migration and wanted to share a few things that seem worth checking before anyone starts moving data. It’s easy to think of migration as simply transferring messages from one platform to another, but there are quite a few details that can affect the final result.
First, I’d recommend making an inventory of the Slack workspace. Check the public and private channels, direct messages, group conversations, files, attachments, threads, and active users. Not every old channel necessarily needs to be moved, so cleaning up inactive or unnecessary data before the migration can save time.
The next thing I’d look at is the Teams structure. Slack channels and Teams channels don't work exactly the same way, so it’s better to decide in advance how the existing Slack channels will map to Teams. User mapping is also important. If people have different email addresses or account names between the two environments, those accounts should be matched correctly before starting the Slack to Teams migration.
For a smaller workspace, some of this can be handled manually. You can create the required Teams channels, download important Slack files, upload them to Teams, and manually preserve critical information. This can work when there are only a few channels and a limited amount of history.
The problem is that manual migration becomes much harder as the workspace grows. Copying individual messages can lose context, attachments can end up separated from the conversations they belong to, and it is easy to overlook direct messages or old but important threads. Recreating hundreds of channels manually can also take a considerable amount of time.
Another thing I would avoid is doing the entire Slack to Teams migration without a test. A small pilot migration is much safer. Pick a few channels and users, move that data first, and then check whether messages, files, replies, users, and channel structure look correct in Teams. If something needs to be changed, you can fix the process before touching the rest of the workspace.
For larger organizations, moving the data in batches can make the process easier to manage. You can migrate a department or selected group of users, verify the results, and then continue with the next batch. Keeping the original Slack workspace accessible until the migration has been properly checked is also a good precaution.
If the workspace contains a large amount of historical data, I’d personally consider using a dedicated migration utility instead of manually copying everything. A free tool can be useful here because you can test the process first without immediately committing to a paid solution.
One option is Kernel Slack to Teams Migration. It can help move Slack data such as channels, direct messages, group chats, files, attachments, and message history, while also providing options for user/channel mapping and selective migration.
The main thing is to treat Slack to Teams migration as a planning exercise rather than just a data-copying task. Audit the workspace, clean up unnecessary content, map users and channels, run a small test, migrate in batches, and verify the results before finally switching over.
First, I’d recommend making an inventory of the Slack workspace. Check the public and private channels, direct messages, group conversations, files, attachments, threads, and active users. Not every old channel necessarily needs to be moved, so cleaning up inactive or unnecessary data before the migration can save time.
The next thing I’d look at is the Teams structure. Slack channels and Teams channels don't work exactly the same way, so it’s better to decide in advance how the existing Slack channels will map to Teams. User mapping is also important. If people have different email addresses or account names between the two environments, those accounts should be matched correctly before starting the Slack to Teams migration.
For a smaller workspace, some of this can be handled manually. You can create the required Teams channels, download important Slack files, upload them to Teams, and manually preserve critical information. This can work when there are only a few channels and a limited amount of history.
The problem is that manual migration becomes much harder as the workspace grows. Copying individual messages can lose context, attachments can end up separated from the conversations they belong to, and it is easy to overlook direct messages or old but important threads. Recreating hundreds of channels manually can also take a considerable amount of time.
Another thing I would avoid is doing the entire Slack to Teams migration without a test. A small pilot migration is much safer. Pick a few channels and users, move that data first, and then check whether messages, files, replies, users, and channel structure look correct in Teams. If something needs to be changed, you can fix the process before touching the rest of the workspace.
For larger organizations, moving the data in batches can make the process easier to manage. You can migrate a department or selected group of users, verify the results, and then continue with the next batch. Keeping the original Slack workspace accessible until the migration has been properly checked is also a good precaution.
If the workspace contains a large amount of historical data, I’d personally consider using a dedicated migration utility instead of manually copying everything. A free tool can be useful here because you can test the process first without immediately committing to a paid solution.
One option is Kernel Slack to Teams Migration. It can help move Slack data such as channels, direct messages, group chats, files, attachments, and message history, while also providing options for user/channel mapping and selective migration.
The main thing is to treat Slack to Teams migration as a planning exercise rather than just a data-copying task. Audit the workspace, clean up unnecessary content, map users and channels, run a small test, migrate in batches, and verify the results before finally switching over.