Mattermost vs Rocket.Chat

Mattermost

Channels and threads are real enough to have their own API endpoints and even a beta operation to move a thread to another channel, with guest accounts, file previews, and, on the Enterprise plan, shared channels and Matrix-protocol federation; edits and deletions are retained in the record by default, and search is documented at a three-million-post scale on Professional and beyond that on Enterprise. We found no public information on pinned or saved items, search filters by channel, person or date, or channel archiving and merging.

Rocket.Chat

Messaging, voice, video and screen sharing with desktop and mobile apps are evidenced, but the evidence says nothing about channels, threads, mentions, file handling or search. For a works council the archive only counts if an eighteen-month-old decision can be found again, and on search the vendor is entirely silent — silence is the finding here.

Mattermost

Transport and at-rest mechanisms are documented concretely — TLS with AES-256 and 2048-bit RSA, disk-level encryption on infrastructure the customer runs, S3 with S3-managed keys, and cluster traffic encrypted with AES-256 — and the deployment guide says plainly that the database is not encrypted at the application layer so that search and compliance reporting keep working, which is the kind of honesty I want more of. Granular role-based access, AD/LDAP sync, SSO, guest accounts and zero-trust channel access are evidenced; we found no public information on end-to-end encryption of message content, device verification, or sessions an administrator can revoke.

Rocket.Chat

"Fully encrypted conversations" and "advanced access and identity controls" are homepage bullets with no mechanism behind them: no key-holder statement, no roles, no SSO, no guest model. The one genuine mitigation is that self-hosted and air-gapped deployment means we, not the vendor, can hold the keys — but the vendor never documents key handling, device verification or session revocation.

Mattermost

Compliance export runs in formats a lawyer already uses — Global Relay EML, Actiance XML, Proofpoint — tracking each message by ID through edits and deletions, with job status visible and every query and download action logged in an audit history explicitly to prevent unauthorised queries; that last part is the co-determination instinct done right. Data Retention Policy and Legal Hold are named at the Enterprise tier and self-hosted telemetry can be opted out; but the default retains everything including deletions rather than deleting, and we found no public information on presence a person can control or on activity analytics and whether they can be switched off organisation-wide.

Rocket.Chat

"Granular data retention policies" and "comprehensive audit logs" are claimed verbatim, which is half of what this criterion needs; the rest — documented export format, legal hold, eDiscovery, user-controlled presence — is absent. And critically, there is not one word about activity analytics or whether anything can be switched off organisation-wide: retention that deletes must be proven, and monitoring must be negotiable away.

Mattermost

Custody really can be the customer's: the same server installs via Kubernetes, Linux or containers, an air-gapped runbook with a bill of materials and registry mirroring is published, FIPS-compliant STIG-hardened images exist, and the customer stands up the database, file storage and TLS themselves — with Matrix-protocol federation and Slack-compatible webhooks giving paths in and past message history exportable via a command-line tool. The compliance export excludes Playbooks and Boards data, and we found no public information on a complete single-format export of an entire workspace.

Rocket.Chat

Open-source code on GitHub plus self-hosting sold as the primary path — on-prem, private cloud, isolated VPC/VPN, fully air-gapped, with 40+ classified programs cited — puts custody genuinely in the customer's hands. What keeps it from the top anchor is exit: no export or migration path in or out is evidenced anywhere in the evidence.

Mattermost

A versioned REST API documented endpoint by endpoint with its permission requirements, incoming and outgoing webhooks available on every plan including the entry edition, Slack-compatible webhook payloads, interactive dialogs and Mattermost Blocks, plus admin-enforced channel locking for webhooks — a control I am glad to see. We found no public information on an app directory, SCIM provisioning, documented rate limits, or an event-subscription model with retries.

Rocket.Chat

A marketplace of pre-built and custom apps plus developer guides is more than a handful of native integrations, but the evidence never documents a REST API, webhooks, slash commands, a bot account model or SSO. I score what is on the page, and the page stops at "no friction, no vendor lock-in" — a slogan, not a surface.

Mattermost

The captured pages show a United States vendor relying on the EU–U.S. Data Privacy Framework and Standard Contractual Clauses, personal information transferred to the United States, Google Analytics on the sites, Azure and AWS named as cloud hosting for US-headquartered providers, and no published list of the subprocessors behind the vendor-managed cloud. The documented air-gapped, self-hosted path with telemetry opt-out is what removes the question in practice for a European deployment, but the contracting entity sits outside the EU and we found no public information on EU hosting or an EU entity.

Rocket.Chat

The contracting entity is Rocket.Chat Technologies Corp. of Wilmington, Delaware, no sovereignty attributes are on record, and the sole EU-hosting evidence is one customer's testimonial about running it on AWS themselves. That this lands above the bottom is architecture, not commitment: on-premises and air-gapped deployment lets us hold the entire archive inside our own jurisdiction, but "free from foreign jurisdiction" is a marketing line with no published subprocessor list or certification behind it.

Mattermost

The captured pricing page routes every named plan to a sales conversation — Professional to "Contact Sales", Enterprise to "Get Pricing", Enterprise Advanced to "Request Quote" — and we found no public per-user price for any tier anywhere in the captures. A limited-use free edition of Enterprise Advanced is offered for technical evaluation, but no buyer can compute an annual invoice from these pages.

Rocket.Chat

Three snapshots of the pricing page yield plan names (Starter, Commercial, Defense, Government) and FAQs about pilots, professional services and special rates — and not a single figure, per-user rate or billing term. The annual invoice is a sales conversation, which for us means the works agreement cannot be costed in advance.