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Comparison · Comms
Stalwart vs Synapse
A side-by-side editorial comparison of Stalwart and Synapse — release velocity, themes, recent moves, and the top alternatives to consider.
Stalwart vs Synapse: at a glance
What is Stalwart?
SCIM v2 lands in the Enterprise tier, opening a provisioning surface beside the protocol work.
Stalwart ships weekly, and 0.16.20 breaks a long run of pure spec-completeness work by adding SCIM v2 to the Enterprise tier: core schema (RFC 7643), protocol (RFC 7644), cursor-based pagination (RFC 9865), the SCIM interoperability profile and the IPSIE lifecycle profile. The rest of the release is the established mix - conference links in calendar invites and alarms, 25 interface translations, and a fix run covering DANE lookup and failure semantics, Redis Sentinel deployments where rediss:// URLs connected to the master in cleartext, and cluster node leases that left removed nodes marked stale indefinitely.
What is Synapse?
Synapse publishes only a changelog link, so its feed records releases without describing them
Synapse is the reference Matrix homeserver, and every entry captured here has the same 80-character body: a link to CHANGES.md on the release branch. Release candidates and finals alternate on a regular rhythm — 1.158, 1.159, and now a second candidate for 1.160 — but no note in this feed says what any of them contain. Judging any individual release from this source is impossible by construction.
Stalwart vs Synapse: editorial side-by-side
Stalwart
6.3COMMS
SCIM v2 lands in the Enterprise tier, opening a provisioning surface beside the protocol work.
◆ Current state
Stalwart ships weekly, and 0.16.20 breaks a long run of pure spec-completeness work by adding SCIM v2 to the Enterprise tier: core schema (RFC 7643), protocol (RFC 7644), cursor-based pagination (RFC 9865), the SCIM interoperability profile and the IPSIE lifecycle profile. The rest of the release is the established mix - conference links in calendar invites and alarms, 25 interface translations, and a fix run covering DANE lookup and failure semantics, Redis Sentinel deployments where rediss:// URLs connected to the master in cleartext, and cluster node leases that left removed nodes marked stale indefinitely.
◆ Where it's heading
The protocol gap-closing continues, with DANE, iMIP, CalDAV and JMAP absorbing corrections every release, but SCIM points at a different axis: who is expected to deploy this. Provisioning, per-tenant branding, cluster lease handling and the recovery-admin impersonation fixes are operator concerns rather than mail-standard concerns, and they have been accumulating since 0.16.15. Calendar remains the least settled surface, now extending into localization rather than correctness alone.
◆ Prediction
SCIM shipped with the interoperability and IPSIE profiles attached, so the near-term work is likely the directory-side corrections that follow first contact with real identity providers - the same pattern the LDAP and SQL directory integrations have been producing. The 25 new translations open a localization surface that has not yet had to survive a release cycle.
Synapse
5.0COMMS
Synapse publishes only a changelog link, so its feed records releases without describing them
◆ Current state
Synapse is the reference Matrix homeserver, and every entry captured here has the same 80-character body: a link to CHANGES.md on the release branch. Release candidates and finals alternate on a regular rhythm — 1.158, 1.159, and now a second candidate for 1.160 — but no note in this feed says what any of them contain. Judging any individual release from this source is impossible by construction.
◆ Where it's heading
What the feed does establish is process. Each minor gets at least one release candidate before the final, candidates and finals are tagged days apart, and the cadence has held steady across three minors. That is a project shipping predictably. Anything about federation, performance or spec support would have to come from the linked changelog, which the feed never inlines.
◆ Prediction
On the established rhythm, 1.160.0 final should follow this second candidate within about a week. The notes will stay link-only unless the release tooling changes.
Alternatives to Stalwart and Synapse
Other Comms products tracked by Sparkpulse, ranked by recent ship velocity. Each card links to a full editorial trajectory and lets you pivot into a head-to-head comparison with either Stalwart or Synapse.
Element X Android
Element X Android ships roughly weekly, alternating real features with fix rounds
Wire
Calling is the one surface Wire's web client touches in every documented release.
Zoho Cliq
Zoho retells Cliq 7.0 as an AI story, and lets customers pick whose model tells it.
Rocket.Chat
Rocket.Chat finishes the 8.8 calling work while the licence wall for SSO gets a date.
Bandwidth
Bandwidth sells trust in the call, and self-service everywhere it used to sell tickets.
See all Stalwart alternatives → · See all Synapse alternatives →
Recent activity from Stalwart and Synapse
Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.
- 1d agoSynapseSynapse 1.160.0rc2: release notes not published to the feed
- 3d agoStalwartSCIM v2 provisioning lands in the Enterprise tier ⚡
- 8d agoSynapseSynapse 1.160.0rc1: release notes not published to the feed
- 9d agoStalwartMySQL key columns need a manual ALTER; Sieve gains spam-score vars
- 15d agoSynapseSynapse 1.159.0 ships with a link-only changelog entry
- 15d agoStalwartResource limits arrive for inbound reports and RocksDB caches
- 22d agoSynapseSynapse 1.159.0rc1: release notes not published to the feed
- 23d agoStalwartIMAP gains UIDONLY, UIDBATCHES and message-limit extensions
- 29d agoSynapseSynapse 1.158.0 ships with a link-only changelog entry
- 1mo agoStalwartJMAP delivery push arrives; strict relays stop rejecting calendar mail
- 1mo agoSynapseSynapse 1.158.0rc1: release notes not published to the feed
- 1mo agoStalwartFix-only release: JMAP semantics and a credential escalation
Frequently asked questions
What is the difference between Stalwart and Synapse?
They serve adjacent needs but don't currently overlap on shipped themes. Stalwart is currently shipping more aggressively (velocity 6.3 vs 5.0), with 1 editorial sparks in the last 30 days against 0. See the at-a-glance table above for a side-by-side breakdown of velocity, recent sparks, and editorial themes.
Is Stalwart better than Synapse?
Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. Stalwart is currently shipping more aggressively (velocity 6.3 vs 5.0), with 1 editorial sparks in the last 30 days against 0. For your specific use case, the alternatives sections above list other Comms products to evaluate alongside.
What are the best alternatives to Stalwart?
Top Stalwart alternatives in Comms are ranked by recent ship velocity. Browse the "Stalwart alternatives" section above for the current picks, or visit /alternatives/stalwart for the full list with editorial commentary on each.
What are the best alternatives to Synapse?
Top Synapse alternatives in Comms are ranked by recent ship velocity. Browse the "Synapse alternatives" section above for the current picks, or visit /alternatives/synapse for the full list with editorial commentary on each.