Mattermost and SlackVault
There's no migration here, because these do different jobs: Mattermost replaces Slack, and SlackVault keeps your team on Slack and copies its messages out. SlackVault has no import from Mattermost and no export built for it.
Where to start
If you're choosing between them and the team is staying on Slack: Slack app setup, then Firebase setup, then the browser extension. The first sync is covered in Syncing & your archive.
Last checked November 7, 2026. Check Mattermost for yourself. SlackVault is not affiliated with or endorsed by Slack.
Which one suits you
Choose Mattermost if you are ready to leave Slack and run the chat yourself on your own servers, with retention and compliance export under your control.
Choose SlackVault if your team wants to keep using Slack as it is and only needs its messages copied into your own Firebase project, without migrating anyone.
Prices
| Plan | Price | Terms as listed | Source |
|---|---|---|---|
| Entry | $0 / month | a free limited-use edition of Enterprise Advanced for technical evaluation | Their page |
| Professional | No listed price | Quote only: the page lists plans and limits (up to 250 users) without a readable price | Their page |
| Enterprise | No listed price | Quote only (Contact sales) | Their page |
Side by side
| What you need | SlackVault | Mattermost |
|---|---|---|
| Saves public channel messages | Yes | Not stated on the pages we checked |
| Saves private channel messages | Yes | Not stated on the pages we checked |
| Saves direct messages and group DMs | Yes | Not stated on the pages we checked |
| Saves thread replies | Yes: A thread that fails to save is skipped, not retried | Not stated on the pages we checked |
| Saves shared files | Yes: File details always; copies only at a public link on our storage, when switched on | Not stated on the pages we checked |
| Runs on its own on a schedule | Yes: Every 15 minutes, while the browser runs | Not stated on the pages we checked |
| Copy lives in storage you control | Partly: Messages in your Firebase project; file copies are not in your storage | Yes: self-hosted: your data stays on your infrastructure Their page |
| Search across the saved history | Yes: The most recent page of messages, up to 50 per query | Yes: core search up to 3 million posts; Elasticsearch beyond Their page |
| Export to open file formats | Yes: JSON, CSV, HTML and Markdown | Partly: compliance export and channel export listed under Enterprise Their page |
| Works without workspace admin rights | Partly: No admin scopes, though a workspace can require approval for new apps | Not stated on the pages we checked |
| Puts records back into Slack | No: No way yet to send records back into Slack | Not stated on the pages we checked |
| Free plan with no time limit | Yes | Partly: Entry is free and limited-use, for evaluation Their page |
What SlackVault does not do
- Messages, channels, members and file records go to your own Firebase project. Supabase is not supported yet.
- Files do not go to your Google Drive or your Firebase project. When file copying is switched on in our extension build, each file uploads to our file storage with its visibility set to public: the link is hard to guess, but anyone holding it can open the file without signing in. Where no storage key is set in the build, no copy is made, and your archive keeps the file’s details and Slack’s link, which works only while Slack serves that file.
- There is no way yet to send records back into Slack.
- The sync runs in a browser extension, every 15 minutes, only while that browser is running.
- SlackVault can copy only what Slack’s API still returns, so anything older than your plan’s window is out of reach unless an earlier sync already saved it.
- If saving one thread fails, the sync logs it and moves on without retrying those replies.
- Search checks the most recent page of messages, up to 50 per query, not the whole archive.
- The extension and the Android app have no store listing yet, and the source code is in a private repository.