# Siilo — Business Instant Messaging

Siilo by Siilo B.V. holds a panel rating of 0.5/5 from 6 AI judges (category median 2/5), as of 2026-10-21. Provenance: provenance unknown; sovereignty: not determined.

- Vendor: Siilo B.V. (https://siilo.com)
- Category: [Business Instant Messaging](https://whats-best.ai/software/instant-messaging.md)
- Provenance (editorial classification): provenance unknown
- Canonical page: https://whats-best.ai/software/instant-messaging/siilo
- Alternatives: https://whats-best.ai/software/instant-messaging/siilo/alternatives ([markdown](https://whats-best.ai/software/instant-messaging/siilo/alternatives.md))
- Data as of: 2026-10-21 · evaluated 2026-10-21 · oldest source captured 2026-10-20

**AI-generated.** Every score, rationale and verdict here is written by a panel of AI judges from public evidence — an analysis, not a hands-on test. Every fact quotes the vendor page it was read from. No score can be bought. How scores are made: https://whats-best.ai/methodology

## At a glance

- Vendor: Siilo B.V.
- Headquarters: Not stated on the vendor’s pages as of 20 Oct 2026
- Data hosting: Not stated on the vendor’s pages as of 20 Oct 2026
- Free plan: Not stated on the vendor’s pages as of 20 Oct 2026

## The panel's verdict

Siilo B.V., now called Doctolib Connect, is judged here as a free messenger for healthcare professionals plus a 'tailored solution' closed secure network for organisations, on a stated 10 M monthly messages from 1.2 M professional users and 225 K care organisations in Europe. Sovereignty and pricing transparency ran highest, both at 1-2; the sovereignty credit rests on the Dutch vendor entity, with no public information on hosting, subprocessors or certification and no sovereignty attributes on record. Integrations sit at a flat 0 across the bench, with no public information on an API, webhooks or provisioning. The genuine splits are in governance and discovery and in deployment control, both spanning 0-1: in governance, the higher scores counted a processor agreement stated as available, while the scores at 0 held that with nothing documented on retention, export or audit logging the archive is not a record system; the deployment split sits on identical findings of a vendor-run service with no public information on self-hosting or a documented exit. Messaging core and encryption and access also ran 0-1 behind 'Data security guaranteed' assurance.

**Speaks for it:**
- Stated network scale of 10 M monthly messages, 1.2 M professional users and 225 K care organisations in Europe
- Individual product publicly stated as the free secure messaging solution for healthcare professionals
- Processor agreement stated as available for GDPR paperwork
- Onboarding and support stated as included with the organisational offering
- Vendor trades as Siilo B.V., a Dutch company form, the European signal behind the sovereignty scores

**Held against it:**
- No public information on channels, threading, search, file handling or how far back message history reaches
- No public information on the encryption mechanism, key custody or guest scoping behind the 'Data security guaranteed' heading
- No public information on retention configuration, discovery export or audit logging of administrative actions
- No public information on self-hosting, a documented export path or the contracting entity under the Doctolib Connect rename
- No public information on an API, webhooks, single sign-on or provisioning, leaving integrations at a flat 0

**Best for:**
- You need a no-cost messenger for individual healthcare professionals and the publicly stated free product covers your users
- You want to reach clinicians on an existing network the vendor states at 1.2 M professional users
- You need a processor agreement in place and a vendor-run hosted service is acceptable to you
- Your association wants a tailored, closed network where members communicate and collaborate

**Avoid if:**
- You need to search and export message history for legal discovery or a works council review
- You must self-host or hold a documented exit path for your clinical archive
- Your sign-off requires documented encryption mechanisms, key custody and administrative audit logs
- Your team builds against the messenger through APIs, bots or directory provisioning

## Scores by judge and criterion

Scores out of 5, each judge scoring independently against the published rubric (v1). "n/r" = not rated: the vendor publishes no price.

| Criterion | The Team Lead | The Security Officer | The Works Council Advocate | The Compliance Counsel | The Platform Engineer | The Skeptic |
| --- | --- | --- | --- | --- | --- | --- |
| Channels, threads & search | 0/5 | 0.5/5 | 0.5/5 | 0.5/5 | 0.5/5 | 0.5/5 |
| Encryption & access control | 0.5/5 | 0.5/5 | 0.5/5 | 0.5/5 | 0.5/5 | 0/5 |
| Retention, discovery & co-determination | 0/5 | 0/5 | 0.5/5 | 0.5/5 | 0.5/5 | 0/5 |
| Deployment & data custody | 0/5 | 0.5/5 | 0/5 | 0/5 | 0.5/5 | 0/5 |
| Integrations & extensibility | 0/5 | 0/5 | 0/5 | 0/5 | 0/5 | 0/5 |
| European sovereignty | 0.5/5 | 1/5 | 0.5/5 | 1/5 | 1/5 | 1/5 |
| Pricing transparency | n/r | n/r | n/r | n/r | n/r | n/r |
| **Weighted verdict** | **0/5** | **0.5/5** | **0.5/5** | **0.5/5** | **0.5/5** | **0.5/5** |

### The judges

- **The Team Lead** (v1.0): Runs a distributed team and needs the tool people actually open. Wants threads that stay readable, search that finds last spring's decision, and channels that can be tidied without losing history. Unmoved by feature lists that do not survive a busy Tuesday.
- **The Security Officer** (v1.0): Assumes the archive will one day be read by someone it was not meant for. Wants end-to-end encryption that ordinary users survive, device verification, sessions an admin can revoke, and a plain statement of what the vendor cannot decrypt.
- **The Works Council Advocate** (v1.0): Knows that a chat log is a record of who spoke to whom at what hour. Wants presence a person controls, no individual activity scoring anywhere, retention that deletes rather than hides, and analytics that can be switched off across the organisation.
- **The Compliance Counsel** (v1.0): Will one day have to produce this archive, edits and deletions included, to a regulator or a court. Wants legal hold, an export a lawyer can work from, retention per channel, and an audit trail that survives the admin who made the change.
- **The Platform Engineer** (v1.0): Would rather run it than rent it, and wants to know whether that is a supported deployment or a hobby build. Cares about open protocols, federation, a plugin system with real permissions, and an upgrade path that does not orphan the customisations.
- **The Skeptic** (v1.0): Reads for the message-history cap, the tier where SSO appears, and what "unlimited" excludes. Has seen "end-to-end encrypted" mean direct messages only, on request, with search disabled — and wants that sentence found rather than assumed.

## European sovereignty — proven facts

No sovereignty finding yet.

## Key facts

Each fact is the vendor's own statement, cited to the source page it was read from ([S*n*] → Sources).

**Legal**
- Documents: yes [S1]

**Product**
- Data security: Data security guaranteed [S1]
- Onboarding support: yes · yes [S1]
- Organisations network: closed secure network for organisations and associations [S1]
- Rebrand: Siilo is now called Doctolib Connect [S1]
- Secure messaging: free secure messaging solution for healthcare professionals [S1]
- Statistics: 10 M · 1.2 M · 225 K [S1]
- User base: yes [S1]

## Questions

### Is Siilo European?

Not determined: the vendor’s pages as captured do not say where Siilo is based.

### Where does Siilo store data?

Not stated on the vendor’s pages as of 20 Oct 2026.

### Does Siilo have a free plan?

Not stated on the vendor’s pages as of 20 Oct 2026.

### What are the best alternatives to Siilo?

As of 20 Oct 2026, the panel rates [Element (3.5/5)](https://whats-best.ai/software/instant-messaging/element), [Mattermost (3.5/5)](https://whats-best.ai/software/instant-messaging/mattermost) and [Stackfield (3/5)](https://whats-best.ai/software/instant-messaging/stackfield) highest among the other 19 Business Instant Messaging products evaluated. Ratings that look equal are rounded to half stars; the order uses the unrounded rating, then the name. The highest-rated European alternative is [Element](https://whats-best.ai/software/instant-messaging/element) (UK / wider Europe). Ratings are the AI panel’s opinion, formed from public evidence: [how scores are made](https://whats-best.ai/methodology#ordering). The full list, with European products first: [Siilo alternatives](https://whats-best.ai/software/instant-messaging/siilo/alternatives).

## What this page leaves out

- We found no public information on pricing on the pages we read (siilo.com). If the vendor publishes it somewhere else, send us the page.
- We found no public information on compliance on the pages we read (siilo.com). If the vendor publishes it somewhere else, send us the page.
- 1 product fact could not be confirmed on the vendor’s page as captured and was left out of this page and of the panel’s material.
- 1 support fact could not be confirmed on the vendor’s page as captured and was left out of this page and of the panel’s material.

## Sources

- [S1] Vendor page: https://siilo.com (checked 2026-10-20)

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Cite as: whats-best.ai, "Siilo — Business Instant Messaging", AI panel analysis, as of 2026-10-21. https://whats-best.ai/software/instant-messaging/siilo

Corrections: https://whats-best.ai/correct/862?target=page