← Back to home
Comparison · Comms

Deepgram vs Stalwart

A side-by-side editorial comparison of Deepgram and Stalwart — release velocity, themes, recent moves, and the top alternatives to consider.

Shared themes:self-hosted

Deepgram vs Stalwart: at a glance

FeatureDeepgramStalwart
SectorCommsComms
Velocity score0.05.0
Sparks · 30d00
Top themesspeech-to-text, diarization, multilingual, self-hostedemail-standards, jmap, imap, dmarc
Last editorial update12d ago23h ago
WebsiteVisit →

What is Deepgram?

Deepgram is widening language coverage while quietly replacing its diarization core.

Deepgram shipped a new batch speaker diarization architecture as an opt-in diarize_model parameter, then made it the default in the May self-hosted release. Alongside it, profanity filtering rolled out to 50+ monolingual languages and then to all multilingual models, numerals support reached Russian, Romanian, and Hebrew, and Gemini 3.1 Flash Lite replaced its preview version in the Voice Agent API.

Read the full Deepgram trajectory →

What is Stalwart?

Stalwart is shipping email's next-generation auth stack while the specs are still in draft.

Stalwart is an all-in-one mail and collaboration server — SMTP, IMAP, JMAP, CalDAV, CardDAV and WebDAV in one binary — releasing every one to two weeks on the 0.16.x line. The last two months read as a standards campaign: DKIM2 and the full DMARCbis set in 0.16.12, VAPID push in 0.16.14, FreeBSD support in 0.16.13, and a run of IMAP extensions (UIDONLY, UIDBATCHES, MESSAGELIMIT/SAVELIMIT) in 0.16.17. Between the additions, most of each release is JMAP conformance repair driven by the jmap-test-suite.

Read the full Stalwart trajectory →

Deepgram vs Stalwart: editorial side-by-side

D0.0

Deepgram is widening language coverage while quietly replacing its diarization core.

◆ Current state

Deepgram shipped a new batch speaker diarization architecture as an opt-in diarize_model parameter, then made it the default in the May self-hosted release. Alongside it, profanity filtering rolled out to 50+ monolingual languages and then to all multilingual models, numerals support reached Russian, Romanian, and Hebrew, and Gemini 3.1 Flash Lite replaced its preview version in the Voice Agent API.

◆ Where it's heading

Two tracks run at once. The model track is a genuine architecture replacement in diarization, moved from opt-in to default inside a week and a half, which is a fast promotion for a core speech component. The coverage track is unglamorous breadth — languages, filters, numerals — that determines whether the platform can be adopted outside English-first markets. The Voice Agent work is managed-model plumbing rather than a direction of its own.

◆ Prediction

Diarization v2 should reach streaming after landing in batch and self-hosted, since that is where the earlier architecture is weakest for live agents. Expect the language-coverage releases to continue at the same steady cadence.

S5.0

Stalwart is shipping email's next-generation auth stack while the specs are still in draft.

◆ Current state

Stalwart is an all-in-one mail and collaboration server — SMTP, IMAP, JMAP, CalDAV, CardDAV and WebDAV in one binary — releasing every one to two weeks on the 0.16.x line. The last two months read as a standards campaign: DKIM2 and the full DMARCbis set in 0.16.12, VAPID push in 0.16.14, FreeBSD support in 0.16.13, and a run of IMAP extensions (UIDONLY, UIDBATCHES, MESSAGELIMIT/SAVELIMIT) in 0.16.17. Between the additions, most of each release is JMAP conformance repair driven by the jmap-test-suite.

◆ Where it's heading

The project is building toward being the reference implementation of the modern mail stack — JMAP first, with the classic protocols held at parity rather than left behind. The fix lists have shifted in character over these eight releases: less "feature does not work", more "spec detail is wrong", which is what a codebase looks like as it converges on conformance. Security and multi-tenancy fixes keep appearing alongside the protocol work, indicating real deployments are exercising the newer subsystems.

◆ Prediction

The next releases most likely track revisions to the drafts already implemented — DKIM2, JMAP push and the calendar drafts are all still moving — rather than adding another protocol surface. Expect continued JMAP conformance fixes until the test suite stops producing them.

Alternatives to Deepgram and Stalwart

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 Deepgram or Stalwart.

See all Deepgram alternatives → · See all Stalwart alternatives →

Recent activity from Deepgram and Stalwart

Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.

  1. 1d agoStalwartIMAP gains UIDONLY, UIDBATCHES and message-limit extensions
  2. 9d agoStalwartJMAP delivery push arrives; strict relays stop rejecting calendar mail
  3. 15d agoStalwartFix-only release: JMAP semantics and a credential escalation
  4. 22d agoStalwartVAPID lands for JMAP Web Push
  5. 1mo agoStalwartFreeBSD support, plus OAuth scopes for IMAP, SMTP and Sieve
  6. 1mo agoStalwartDKIM2 and the full DMARCbis suite ship in one release
  7. 2mo agoDeepgramProfanity Filtering Now Supported for All Multilingual Models; Korean Spacing Improvements
  8. 2mo agoDeepgramGemini 3.1 Flash Lite Now Available
  9. 2mo agoDeepgramNumerals Support Now Available for 3 New Languages: Russian, Romanian, and Hebrew (Monolingual Models)
  10. 3mo agoDeepgramSelf-hosted May release ships Diarization v2 by default
  11. 3mo agoDeepgramProfanity Filtering Now Available in 50+ Languages
  12. 3mo agoDeepgramDiarization v2: Improved Batch Speaker Diarization

Frequently asked questions

What is the difference between Deepgram and Stalwart?

Both compete on the same themes — self-hosted — within Comms. Stalwart is currently shipping more aggressively (velocity 5.0 vs 0.0), with 0 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 Deepgram better than Stalwart?

Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. Stalwart is currently shipping more aggressively (velocity 5.0 vs 0.0), with 0 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 Deepgram?

Top Deepgram alternatives in Comms are ranked by recent ship velocity. Browse the "Deepgram alternatives" section above for the current picks, or visit /alternatives/deepgram for the full list with editorial commentary on each.

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.