← 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-hostedmail-server, jmap, imap, rfc-compliance
Last editorial update19d ago21h 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 chasing mail RFCs and its own storage layer at the same time

Stalwart ships roughly weekly, and the releases divide cleanly between standards implementation and correctness work. v0.16.18 turns toward resource control — bounds on decompressed inbound DMARC and TLS report size, a cap on RocksDB block-cache memory, column families tuned per access pattern, and a queue scheduler that stops rescanning from the earliest pending event. The preceding releases added IMAP UIDONLY, UIDBATCHES and MESSAGELIMIT, plus JMAP email push and VAPID.

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 chasing mail RFCs and its own storage layer at the same time

◆ Current state

Stalwart ships roughly weekly, and the releases divide cleanly between standards implementation and correctness work. v0.16.18 turns toward resource control — bounds on decompressed inbound DMARC and TLS report size, a cap on RocksDB block-cache memory, column families tuned per access pattern, and a queue scheduler that stops rescanning from the earliest pending event. The preceding releases added IMAP UIDONLY, UIDBATCHES and MESSAGELIMIT, plus JMAP email push and VAPID.

◆ Where it's heading

Two threads run through every release. One is RFC coverage across IMAP, JMAP, CalDAV and WebDAV, implemented close to the specification including drafts. The other is a long tail of protocol-conformance fixes, many of them cases where JMAP and IMAP disagreed about the same state. The newest release adds a third: memory and scheduling limits, which is what a server codebase starts doing when deployments get large enough for defaults to hurt.

◆ Prediction

Expect continued RFC additions across the JMAP and IMAP surfaces, with more of the storage-tuning work that v0.16.18 started as RocksDB deployments scale.

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 agoStalwartResource limits arrive for inbound reports and RocksDB caches
  2. 8d agoStalwartIMAP gains UIDONLY, UIDBATCHES and message-limit extensions
  3. 16d agoStalwartJMAP delivery push arrives; strict relays stop rejecting calendar mail
  4. 23d agoStalwartFix-only release: JMAP semantics and a credential escalation
  5. 29d agoStalwartVAPID lands for JMAP Web Push
  6. 1mo agoStalwartFreeBSD support, plus OAuth scopes for IMAP, SMTP and Sieve
  7. 3mo agoDeepgramProfanity Filtering Now Supported for All Multilingual Models; Korean Spacing Improvements
  8. 3mo agoDeepgramGemini 3.1 Flash Lite Now Available
  9. 3mo 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.