Zammad's means run higher on ticketing core (6.0 to 1.0), omnichannel (6.8 to 0.3), knowledge and self-service (4.2 to 0.2), integrations (4.0 to 0.0), sovereignty (6.3 to 3.5) and pricing transparency (6.8 to 0.0); OTRS publishes no prices, and pricing was not weighted against it. The split: customer data protection (3.8 to 2.8), one judge leaning OTRS, five lean Zammad. OTRS's case there is legal posture — German contracting entity, named external data protection officer, stated retention periods — scored 2–4 on the credit those practices earn; Zammad's captures show no tenant DPA, retention period or audit log evidenced. OTRS's other scores rest on legal pages where we found no public information on queues, routing, SLAs, APIs or connectors. Weighted totals per judge run Zammad 5.3–5.6 against OTRS 0.5–2.2. Zammad's gaps: only GitHub/GitLab and Grafana/Elasticsearch named as integrations; telephony appears in no tier's channel list and carries no price.
Choose OTRS if
Your contract must sit with a German-registered vendor — OTRS's legal entity jurisdiction is DE, and the imprint names OTRS GmbH, Oberursel (Amtsgericht Frankfurt am Main HRB 143059, VAT DE453344897).
You need a named external data protection officer documented before signature — OTRS's privacy-policy captures show one.
Your compliance gate is stated retention periods in a published privacy policy — OTRS's captures state them.
Your reviewers credit data-protection practices evidenced on the vendor's own site — on customer data protection, where OTRS scores spread 2–4, one judge leaned OTRS.
Choose Zammad if
You need core ticketing evidenced — states, assignment, escalations, SLAs, macros, templates and automation rules are named in Zammad's captures; ticketing core means 6.0 to 1.0, with 6 judges leaning Zammad.
Your customers reach you on many channels — email, web form, SMS, chat, Telegram, Facebook and WhatsApp are priced per tier into a unified ticket view (omnichannel 6.8 to 0.3).
You must budget before pilot — Zammad publishes €7/€16/€25 per agent per month plus a metered €0.03 per AI call, with VAT treatment stated (pricing transparency 6.8).
Your residency requirement is EU-only — Zammad's data residency attribute reads EU only and its subprocessor exposure reads none.
You want the self-hosted option — Zammad is offered cloud or self-hosted, and its sovereignty scores of 6–7 credit that option (sovereignty means 6.3 to 3.5).
Read this comparison as one judge. Each weighs the same scores by what they care about.
The Support Lead
Runs a team of twelve against an SLA the sales team promised. Wants routing that reflects skill, timers that warn before they breach, and reporting she can take to a quarterly review. Reads "AI-powered" as a claim to be checked against the queue on a Monday morning.
OTRS
Zammad
This judge's pick
Criterion by criterion
Ticketing, queues & SLA
OTRS
Three homepage captures and the legal pages don't evidence a single ticketing capability — no routing, no SLA timers, no escalation chains, no search, not even a status model. All I have is the 'Customer Service & Helpdesk' category label and a 'service management suite' descriptor, which gets it off the absolute floor but tells me nothing I could put in front of my team on a Monday.
Zammad
The bones are evidenced — "States · Assignment · Escalations", SLAs, macros, automation rules, overviews and reporting — and escalations plus SLAs are what I need against a promised SLA. But nothing shows breach warnings, business-hours-aware SLA policies, per-agent resolution reporting, merge/split or even that search exists; and SLAs only enter at Professional v2, so Starter buyers track work they can't measure.
Channels in one queue
OTRS
Nothing in the evidence evidences any channel at all — not email handling, not a portal, not a single messenger — let alone channels landing in one queue with one history. rubric level 0 says email only; the evidence gives me less than that to work with, so this is the floor.
Zammad
Email, web form, chat, Telegram, WhatsApp and Facebook are all placed as priced channels and the unified ticket view with customer profile suggests one history per customer. Missing: no evidence of call logging for the claimed telephony integration, no messenger consent handling, no requester-visible portal — and chat and WhatsApp are tier-gated, so "one queue" depends on which invoice you sign.
Knowledge base & deflection
OTRS
The only knowledge-base-adjacent fact anywhere is that OTRS's own website has FAQs — that's their marketing site, not a product help centre, article workflow, or deflection reporting. There is no evidence the product reduces ticket volume at all.
Zammad
A help centre and knowledge base exist with the deflection promise spelled out ("without opening a ticket") and multilingual articles from Plus upward. No editorial workflow, draft/publish, article insert into replies, review dates or deflection reporting appears anywhere in the evidence — knowledge is a shelf, not a managed asset.
Customer data protection
OTRS
Credit where due: a published privacy statement, GDPR page and Trust Center exist, a named external DPO is on record, and retention periods are actually stated (10 years general, 6 months application data) — but every one of those governs OTRS's own website and CRM, not the helpdesk product. Nothing evidences agent roles, queue-level visibility, per-queue retention rules, a ticket audit log, redaction, or an executable deletion of a requester's data inside the product, which caps this at the DPA-on-request-and-coarse-practices level.
Zammad
Configurable roles and permissions, transport encryption, 2FA, device management, an ISO27001 German data centre, and a self-hosted route that removes vendor access altogether are all evidenced. But there is no published DPA, no stated retention period for tenant ticket data, and no evidenced in-product erasure execution — the GDPR rights list and auto-delete text in the privacy policy govern Zammad's own website inquiries, not my instance.
Integrations & API
OTRS
No API, no webhooks, no SSO, no named CRM or shop integration — nothing. The named Google, HubSpot and 6sense entries in are the vendor's own website marketing stack, not product integrations, and I won't count them as such.
Zammad
"Open APIs and ready-to-use integrations" plus named GitHub/GitLab and Grafana/Elasticsearch connections are the entire evidence base. No CRM or shop system is named, and webhooks, SSO, rate limits, SCIM and any sandbox are silent — an API I can't confirm past the marketing claim is an API I can't plan a build on.
European sovereignty
OTRS
The contracting entity is genuinely German — OTRS GmbH, Amtsgericht Frankfurt HRB 143059, Oberursel address, German VAT — which rules out the bottom anchors. But hosting and data residency for a customer's ticket archive are stated nowhere, the product's own subprocessor list is absent, and the vendor's own chain runs US processors (Google Tag Manager, LinkedIn, Vimeo) with third-country transfers declared possible — where my archive lives is the first question I ask, and this sheet can't answer it.
Zammad
The contracting entity is a German GmbH with a Charlottenburg commercial register number, hosting is German on an ISO27001-certified data centre, and self-hosting exists for keeping the archive on our own infrastructure. But the data-centre provider is unnamed, there is no subprocessor list for the product itself (Matomo and Moosend cover only their website), and the pipeline marks residency and subprocessor exposure as unconfirmed — so I can't give the transparency an anchor-8 buyer would audit.
Pricing transparency
OTRS
Three separate captures of the homepage produced not one price, tier, add-on or billing term. A support lead can't compute any invoice from this, so it's the floor.
Zammad
I can compute the tiered invoice from public pages alone: per-agent prices, agent caps, channel placement per tier (WhatsApp in Plus, SLAs in Professional), VAT explicitly excluded, and even the AI meter at €0.03 per call. What keeps it off rubric level 8: telephony is claimed on the product page yet appears in no priced tier, and billing commitment and minimum term are unstated.
Sovereignty, side by side
Dimension
OTRS
Zammad
Legal entity
Incorporated in DE
Incorporated in DE
Ownership
Not determined
Not determined
Data residency
Not determined
EU only
Subprocessors
Not determined
Not determined
Facts, side by side
Only facts both products carry under the same definition — anything else would not be a fair row.