Mattermost vs Rocket.Chat

Mattermost

Channels, real threads and a documented thread API are evidenced, and at least the search cap is printed rather than hidden: core search up to three million posts on Professional, enterprise search beyond three million on Enterprise. I found no public information on pinned or saved items, mentions and reactions, or search filters by channel, person and date, and the thread-move endpoint is flagged as beta. Default behaviour retains every message including edits and deletes plus all files, so the history itself appears uncapped.

Rocket.Chat

The evidence offers 'messaging, voice, video and screen sharing' and stops there — no channels, no threads, no mentions, no file handling, no search, and no history limit stated anywhere. Whether a decision made eighteen months ago is findable is precisely the question this evidence cannot answer, which leaves it just above the floor.

Mattermost

The sentence I hunt for exists here: the database holds messages unencrypted specifically so search and compliance reporting of history work, which means TLS in transit and disk-level encryption at rest — no end-to-end encryption claim appears on the captured pages. Single sign-on and multifactor authentication sit on Professional, granular role-based and attribute-based controls on Enterprise, so the tier map is visible. I found no public information on device verification or session management an administrator can revoke.

Rocket.Chat

'Fully encrypted conversations' is a slogan, not a mechanism: the evidence never says what is encrypted, against whom, who holds the keys, whether E2EE exists as a mode, or where SSO and guest scoping live. Only the self-hosted and air-gapped deployment, which keeps the keys with the customer by construction, lifts this off the floor.

Mattermost

The discovery machinery is unusually concrete: compliance exports in CSV, Actiance XML, Global Relay EML and Proofpoint formats, edits and deletions tracked by message ID, channel member history included, past history exportable by command line, and every query and download logged in an audit history — with Playbooks and Boards explicitly excluded, which I respect being told. Legal hold and data retention policy appear as feature names on Enterprise without documented mechanism, and the audit trail I can see covers compliance queries rather than all administrative actions. I found no public information on activity analytics being switchable off organisation-wide.

Rocket.Chat

'Granular data retention policies' and 'comprehensive audit logs' appear as feature names, never as documented behaviour — no export format, no legal hold, no eDiscovery, no analytics switch-off. Named but unproven parks this between the manual-export floor and the configurable-retention anchor.

Mattermost

Self-hosting is documented as a first-class path: Kubernetes, Linux and container methods install the same server, an air-gapped runbook with registry mirroring is published, FIPS-compliant STIG-hardened images exist, and the privacy policy states the customer controls processing of end-user data on self-hosted products. Federation via Matrix protocol interoperability is listed at Enterprise tier. The captured pages do not state a licence or source-availability model for the server, so I score the deployment paths rather than assume an open-source core.

Rocket.Chat

Open source on GitHub, plus on-prem, private cloud, isolated VPC/VPN and full air-gap with 40+ classified programs cited — custody really can be the customer's, and the self-hosted edition is clearly the flagship rather than a laggard. What the evidence never shows is the exit: no documented export format or migration path, which holds this below the top anchor.

Mattermost

A versioned REST API with bearer authentication, incoming and outgoing webhooks with Slack-compatible payloads, interactive dialogs and structured interactive blocks, plus single sign-on — a solid middle of this scale. I found no public information on slash commands, SCIM provisioning, documented rate limits, an app directory or a sandbox. Bot posts are acknowledged in compliance export contents, but no bot account model is documented on the captured pages.

Rocket.Chat

An apps marketplace with pre-built and custom apps, plus developer guides, says there is a buildable platform without a partner agreement. But webhooks, bot account model, SCIM provisioning and documented rate limits are all unlisted, so this lands at the documented-API anchor rather than the app-framework one.

Mattermost

The contracting entity is Mattermost, Inc. in the United States, transfers to the USA are disclosed, and reliance is on the EU-U.S. Data Privacy Framework and Standard Contractual Clauses; the captured pages give no hosting location and no published subprocessor list for the vendor-managed cloud, while Azure and AWS appear as cloud options for US-headquartered providers. What lifts this off the floor is documented self-hosting where the customer controls the data and telemetry can be opted out — custody can move to the customer, but the vendor chain remains American and its footprint remains unstated.

Rocket.Chat

No sovereignty attributes on record and the contracting entity sits in Wilmington, Delaware — subprocessors unnamed, vendor hosting unstated. The only EU hosting in evidence is a customer's own AWS deployment, and 'sovereign cloud' is a deployment mode, not a European chain; this product answers the question by letting you host it yourself, which earns partial credit and nothing more.

Mattermost

Every tier routes to sales — Professional says Contact Sales, Enterprise says Get Pricing, Enterprise Advanced says Request Quote — and no per-user figure appears anywhere on the captured pricing pages. Credit for labelled tier boundaries: single sign-on at Professional, compliance export and retention policy from Enterprise, Professional support capped at 250 users, plus a free limited-use evaluation edition. No annual invoice is computable from the public pages, whatever the headcount.

Rocket.Chat

Three captures of the pricing page and not one number: no per-user price, no billing period, no VAT treatment, no tier boundaries. What we get is the existence of a Starter plan, a special-rates FAQ, and a footnote admitting some listed features are 'planned for release in 2026' — plan labels, not a computable invoice.