Mattermost vs Rocket.Chat

Mattermost

Channel-based collaboration, threaded discussions, link and file previews, guest accounts and search up to three million posts are documented, and the thread structure is exposed through the API with permissions and pagination detail. Compliance exports flag edits and deletions per message, which tells me the history beneath the surface stays intact. We found no public information on pinned and saved items, on end-user search filters by channel, person or date, or on channel lifecycle such as archive and rename without losing history.

Rocket.Chat

The only messaging evidence is 'Unify messaging, voice, video, and screen sharing' with mobile and desktop apps; the evidence is silent on channels, threads, search, and history limits. When I need to find a decision made eighteen months ago, silence on search is a finding in itself.

Mattermost

TLS with named ciphers, encryption-at-rest through customer-side disk and database methods, granular role-based access controls, SSO with SAML assertion encryption and attribute-based zero-trust channel access at the top tier are all documented. The vendor states plainly that the database itself holds no encryption so that search and compliance reporting work — candour I value, though it confirms the server sees plaintext. We found no public information on end-to-end encryption, device verification, or session management an administrator can revoke.

Rocket.Chat

'Fully encrypted conversations' and 'advanced access and identity controls' are asserted with zero documented mechanism — no statement of key custody, no E2EE, no session revocation, no guest scoping. Self-hosting means the customer can hold the keys, but nothing on this sheet documents that they do.

Mattermost

The compliance export is the real thing: CSV, Actiance XML, Global Relay EML and Proofpoint formats, edits and deletions flagged per message, message tracking across export batches, channel member history, past-history export from a timestamp, and query and download actions logged in an audit history. Legal hold and eDiscovery automation are named on the Enterprise plan, and the default is to retain everything including edits and deletes. Two reservations hold this back: Playbooks and Boards content is documented as excluded from compliance export, so decisions that migrate there escape the subpoena, and we found no public information on per-channel retention granularity or organisation-wide switching of activity analytics.

Rocket.Chat

'Granular data retention policies' and 'comprehensive audit logs' are named, which is more than most sheets give me, but nothing evidences legal hold, an eDiscovery export format, or whether the audit trail captures edits and deletions. The words I need appear; the mechanisms a court will ask about do not.

Mattermost

Custody can be entirely the customer's: the same server installs via Kubernetes, Linux or containers, high availability is self-managed, FIPS-compliant STIG-hardened images are published, and the air-gap documentation includes a runbook, bill of materials and registry mirroring. The privacy policy states that with self-hosted products the customer controls the processing of end user data, and federation via Matrix protocol interoperability is named on the Enterprise plan. We found no public information on a documented migration path in and out, and the source availability of the server is not confirmed on the captured pages.

Rocket.Chat

Custody is genuinely evidenced: open-source code on GitHub, a self-hosted server, and on-prem, private cloud, VPC/VPN and fully air-gapped options claimed across 40+ classified programs. What withholds a higher score is exit: no export format, files and metadata included, is documented anywhere on this sheet, and 'no vendor lock-in' is a slogan, not a migration path.

Mattermost

A documented REST API with bearer authentication and per-endpoint permission detail, incoming and outgoing webhooks with Slack-format compatibility, interactive components via blocks and dialogs, and SSO with AD/LDAP sync are all evidenced. Administrators can enforce channel locking on webhooks and enable webhook debugging, and posts from plugins and bots appear in the compliance record, so automations stay capturable. We found no public information on SCIM provisioning, documented rate limits, event subscriptions with retries, or an app directory.

Rocket.Chat

An apps marketplace with both pre-built and custom apps plus developer guides evidences a real extensibility surface beyond a webhook list. But the evidence says nothing about a documented API, bot model, SCIM provisioning, or rate limits — a framework is named, its plumbing is not.

Mattermost

The contracting entity is Mattermost, Inc., a US company relying on the Data Privacy Framework and Standard Contractual Clauses, with transfers to the United States named, a US-based premier support tier on offer, and Google Analytics on the vendor's sites; we found no public information on EU data residency, an EU contracting entity, or a published subprocessor list for the vendor-managed cloud. The self-hosted and air-gapped options put the archive itself in the customer's hands, which is the only reason this clears the floor. Hosted push notifications and self-hosted telemetry are opt-out, so the European buyer must configure rather than assume.

Rocket.Chat

The contracting entity is a Delaware corporation, the pipeline records no sovereignty attributes, and no subprocessor is named. The only EU datum is a customer's own AWS deployment testimonial, plus an unspecified 'sovereign cloud' deployment option for government — an option is not a jurisdiction, and 'free from foreign jurisdiction' is asserted, not evidenced.

Mattermost

Every plan routes to Contact Sales, Get Pricing or Request Quote, and we found no public per-user price, billing period, VAT treatment or minimum term; only a free limited-use evaluation edition is public. The compliance monitoring and export features a regulated buyer needs sit on the Enterprise and Enterprise Advanced tiers, both unpriced. A buyer cannot compute an annual invoice for any headcount from these pages.

Rocket.Chat

Three captures of the pricing page yielded plan names, FAQs about special rates, pilots and professional services, and a Starter tier for evaluation — not one per-user figure, billing period, or feature boundary. I cannot compute an annual invoice from this, and I cannot tell which tier buys the retention and audit controls; that is sales-conversation pricing with extra steps.