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Comparison · Collab
Calibre-Web vs Komga
A side-by-side editorial comparison of Calibre-Web and Komga — release velocity, themes, recent moves, and the top alternatives to consider.
Shared themes:self-hosted
Calibre-Web vs Komga: at a glance
What is Calibre-Web?
A yearly release cadence spent almost entirely on Kobo sync and self-hosting hardening.
Calibre-Web is a self-hosted web frontend for an existing Calibre ebook library. It ships roughly one consolidated release a year, each a large bundle in which a short new-feature list sits on top of a much longer set of bug and security fixes. The most recent releases added MOBI and audio metadata extraction on upload, reverse-proxy login via a shared secret header, multi-book editing, and Calibre 9 compatibility. Kobo e-reader sync absorbs a disproportionate share of every release.
What is Komga?
Komga is rewriting its web UI in the open, shipping the beta alongside the old one.
Komga's release cadence is dominated by NextUI, a ground-up rewrite of the web interface that landed in beta with 1.26.0 and is served next to the existing UI at /next rather than replacing it. The three patch releases that followed within 48 hours were almost entirely NextUI shakedown work — scroll restoration, selection behavior, stylesheets failing to load under Tomcat. Underneath the interface work the server keeps widening format support, with rar5 handling in plain Java and solid rar4 archives earlier in the summer.
Calibre-Web vs Komga: editorial side-by-side
Calibre-Web
2.5COLLAB
A yearly release cadence spent almost entirely on Kobo sync and self-hosting hardening.
◆ Current state
Calibre-Web is a self-hosted web frontend for an existing Calibre ebook library. It ships roughly one consolidated release a year, each a large bundle in which a short new-feature list sits on top of a much longer set of bug and security fixes. The most recent releases added MOBI and audio metadata extraction on upload, reverse-proxy login via a shared secret header, multi-book editing, and Calibre 9 compatibility. Kobo e-reader sync absorbs a disproportionate share of every release.
◆ Where it's heading
Development here is maintenance-shaped rather than expansion-shaped, and the shape is getting more pronounced: 0.6.27 lists two new features against roughly thirty fixes, where 0.6.25 a year earlier listed close to twenty additions. The sustained investment sits in two places — keeping Kobo sync working against a vendor API that keeps moving underneath it, and making the app behave correctly behind reverse proxies and in container deployments. Compatibility work with current Calibre and current Python versions is treated as release-blocking, which is the right read for a project whose value depends entirely on staying installable.
◆ Prediction
Given the cadence, expect the next release six to twelve months out as another consolidated bundle led by Kobo sync repairs and Python or Calibre compatibility work rather than new capability. Reverse-proxy authentication is the one area with visible recent momentum, so further authentication-integration options are the most plausible genuinely new addition.
Komga
6.3COLLAB
Komga is rewriting its web UI in the open, shipping the beta alongside the old one.
◆ Current state
Komga's release cadence is dominated by NextUI, a ground-up rewrite of the web interface that landed in beta with 1.26.0 and is served next to the existing UI at /next rather than replacing it. The three patch releases that followed within 48 hours were almost entirely NextUI shakedown work — scroll restoration, selection behavior, stylesheets failing to load under Tomcat. Underneath the interface work the server keeps widening format support, with rar5 handling in plain Java and solid rar4 archives earlier in the summer.
◆ Where it's heading
The project is running a long, deliberately cautious frontend migration: both UIs ship in the same binary, the feature gap is tracked publicly in an issue, and users opt in by URL. That arrangement should persist across several minor versions before the old WebUI is retired. The parallel v2 referential API suggests the rewrite is also being used to revise the server contract rather than only restyle the client.
◆ Prediction
Near-term releases should keep closing the NextUI feature gap issue by issue, with patch releases landing within days of each other. The old WebUI is unlikely to be removed before NextUI reaches parity and browser refresh stops falling back to it.
Alternatives to Calibre-Web and Komga
Other Collab 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 Calibre-Web or Komga.
Read the Docs
Read the Docs is rebuilding its build farm around uv and isolated builders, one week at a time.
CommaFeed
CommaFeed is patching its way through the attack surface a self-hosted reader inherits
SiYuan
SiYuan stabilises 3.8.1 after a seven-build beta run, all of it widening the agent surface it opened in 3.8.0
Hive
Hive ships in batches, and this one is all planning accuracy and admin control.
Teable
Teable ships daily, and the work has moved from grid features to platform governance.
See all Calibre-Web alternatives → · See all Komga alternatives →
Recent activity from Calibre-Web and Komga
Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.
- 7d agoKomgaTranslation updates and a release tooling fix
- 7d agoKomgaNextUI beta fixes: scroll, selection, and loading states
- 9d agoKomgaNextUI beta: a parallel rewrite of the Komga web interface ⚡
- 9d agoKomgaFix missing NextUI stylesheets when served from Tomcat
- 10d agoCalibre-WebMOBI metadata on upload, reverse-proxy shared-secret login
- 1mo agoKomgaSolid RAR4 archive support
- 3mo agoKomgaFixes for EPUB parsing, Kobo, KOReader, and OPDS2
- 6mo agoCalibre-WebMulti-book editing, Calibre 9 compatibility, API-key leak fixed
- 0y agoCalibre-WebKepub reading, bulk book actions, official Python 3.12 support
- 1y agoCalibre-WebAudio-file metadata extraction and multi-format uploads
- 1y agoCalibre-WebEPUB reader themes and font sizing, multi-address Kindle sending
- 1y agoCalibre-WebSplit library locations, metadata backup, upload mimetype checks
Frequently asked questions
What is the difference between Calibre-Web and Komga?
Both compete on the same themes — self-hosted — within Collab. Komga is currently shipping more aggressively (velocity 6.3 vs 2.5), 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 Calibre-Web better than Komga?
Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. Komga is currently shipping more aggressively (velocity 6.3 vs 2.5), with 1 editorial sparks in the last 30 days against 0. For your specific use case, the alternatives sections above list other Collab products to evaluate alongside.
What are the best alternatives to Calibre-Web?
Top Calibre-Web alternatives in Collab are ranked by recent ship velocity. Browse the "Calibre-Web alternatives" section above for the current picks, or visit /alternatives/calibre-web for the full list with editorial commentary on each.
What are the best alternatives to Komga?
Top Komga alternatives in Collab are ranked by recent ship velocity. Browse the "Komga alternatives" section above for the current picks, or visit /alternatives/komga for the full list with editorial commentary on each.