Mattermost vs Matrix

Which platform fits which scenario

This table maps common deployment scenarios to the platform that fits better and the reason behind the pick. Read each row as a default, then check the condition in the last column that could reverse it, since federation, plan gating and operating staff change the answer.

How Mattermost and Synapse are built and what that means for operations

Mattermost and Synapse take very different shapes. One is a single server binary backed by PostgreSQL, the other is a federated homeserver that can split into worker processes coordinated through Redis. The cards below cover the decisions each design forces on the team that runs it.

Federation, licensing, SSO and bridges compared

This table sets Mattermost's single-vendor model against Matrix's federated protocol on the factors that decide a shortlist: who you can talk to, what the license and paid tiers gate, how identity is wired and what the database and high availability rules demand. Read each row as a question to answer for your own organization, since federation value depends on who your partners are and SSO value depends on your identity provider.

Licensing and paid editions on each side

What drives the running cost of each platform

Running either platform costs more than its license line. The main drivers are the infrastructure and storage each product needs for resilience, the people who run it, and the release cadence that sets how often someone upgrades. Read each card with a written quote and an upgrade plan in hand.

Moving users from Mattermost to Matrix, or back

This sequence moves a team's conversations, identities and history between Mattermost and a Matrix deployment with a known cut-over point, a bridge period where both run, and a retirement step only after the new service has been checked. It is written for teams that have already chosen a direction and need the order of work more than the reasons for it.

1. Fix identity and domain naming first

   Before any account or room is created, the team decides the Matrix server_name, the domain that will appear in every user ID (for example @user:example.com) and in every room identifier. This value is set in the Synapse configuration and cannot be treated casually, because it is baked into identifiers that other servers use for federation. Map each Mattermost user to a Matrix identity source, whether that is SSO through Matrix Authentication Service, an upstream OpenID Connect or SAML provider, or local accounts, and confirm which directory attributes will drive account creation and deactivation. The step is done when a written naming and identity plan has been signed off by the security and identity owners, and a test account has signed in end to end on a non-production homeserver. If the team cannot confirm the server_name it wants to keep for the next several years, it should stop here, because changing it later is effectively a new deployment.

2. Map channels and teams to rooms

   Each Mattermost team, public channel, private channel and direct message group is listed in a mapping sheet with the proposed Matrix room, its join rules, its visibility and its owner. Matrix rooms are not a one-to-one copy of Mattermost channels, so the team decides whether a team becomes a space, a set of rooms, or a flat list, and records the decision. Permissions are rebuilt on the Matrix side rather than carried over, so each room's power levels and membership rules are written down before users are invited. The output is an approved mapping document and a test room set created on the non-production homeserver, with a sample of users confirming that membership and visibility match the sheet.

3. Decide which history transfers

   The team separates three kinds of content: messages that must be kept for records or legal hold, messages that are useful context but can be archived, and content that can be dropped. A history import from Mattermost into Matrix is not a supported standard path in the facts available here, so the team should confirm with Element and with its own migration tooling whether any message history, attachments or reactions can be imported and in what form. Often the practical result is a read-only archive of the old Mattermost export, kept under the existing retention policy, with the Matrix side starting fresh. The step is complete when the retention owner has approved what is archived, where the archive lives, who can access it and how long it is kept under the organization's own policy.

4. Stand up bridges and run both services in parallel

   For the overlap period, the team deploys any bridges it needs from the Matrix ecosystem list, such as bridges to other chat services, and tests them against the mapped rooms. Bridges relay messages rather than migrate them, so the team confirms which message types, edits, reactions, file attachments and threads each bridge handles, and what happens to identity mapping. Bridges are additional services with their own operating effort, upgrade cycle and security review, and they need to be counted in the running cost. Users are told which service is authoritative for which room during the overlap. The step is done when a pilot group has held real conversations across both systems for a period agreed in the plan, and the operations team has documented bridge failures and how they are detected.

5. Test rollback and confirm upgrade limits

   Before any cut-over, the team tests the restore path on the Matrix side. The Synapse upgrade notes warn that rolling back can be difficult because of database schema changes between releases, so a rollback is not a simple binary swap. The team takes a backup of the PostgreSQL database, records the exact Synapse version in use, and rehearses restoring that backup to a clean environment. It also confirms the minimum PostgreSQL and Python versions for the chosen release, since Synapse drops support for versions that reach upstream end of life. The output is a written rollback runbook that has been tested once, with the time and the steps recorded. The same risk applies in reverse: a move from Matrix back to Mattermost has its own schema and identity mapping, so the team should rehearse that direction too if it is a realistic option.

6. Cut over users in controlled groups

   Users are moved in groups, starting with a pilot team and expanding only after support tickets and bridge logs have been reviewed. For each group, the team sends the new login instructions, confirms that accounts are provisioned through the chosen identity path, and checks that membership in the mapped rooms is correct. Mobile clients and desktop clients are tested separately, and the team records which notification settings users must change. The step is done for each group when the group has signed in on the new service, sent and received messages in mapped rooms, and the help desk has closed the first wave of access issues. Any group that fails a check is held back and investigated before the next group moves.

7. Retire the old service with a documented exit

   Once all groups have moved and the bridge period has ended, the team switches the old service to read-only, announces a final date agreed in the plan, and confirms the archive created earlier is complete and accessible. Bridges are shut down, integrations and webhooks are disconnected, and DNS and certificates for the old service are removed on a schedule. The team keeps the rollback runbook and the final backup until its retention owner agrees they can be deleted. The step is complete when the old service no longer accepts new messages, the archive is verified, the decommissioning record is signed by the service owner, and the compliance owner has received the evidence that the change was carried out under the agreed controls.

8. Confirm open points with each vendor

   Some points should be confirmed directly with Mattermost and with Element, or with the chosen Matrix service partner, rather than assumed. The team asks Mattermost which export formats and data it provides for a departing organization, and whether its current plan covers the features used in the migration. It asks Element which Synapse release it recommends for the planned deployment, which upgrade path it supports, and whether any history import or bridge option is supported for its licence tier. Commercial questions, including support windows and any AGPL exception needs, go into the written quote. The step is done when each answer is recorded in the migration file with the name of the person who gave it and the date.

Where Matrix and Mattermost projects usually run long

Questions buyers ask before choosing between Mattermost and Matrix

Four risks to check before committing to either platform

Mattermost and Matrix fail in different places. Mattermost's risks cluster around paid tiers and shared storage, while Matrix's cluster around federation settings, upgrade discipline and the bridges that connect it to other chat systems. Run each check in a test environment before you sign a subscription or commit users to a homeserver.

How DeployOpen helps choose and implement either platform