head to head · open source
cobalt vs Spark
cobalt has 45,722 GitHub stars, 4,031 forks, 269 open issues and last shipped 7 months ago. Spark has 606 stars, 445 forks, 7 open issues and last shipped 2 days ago. cobalt leads on adoption by 7,445% (45,722 vs 606 stars). cobalt is written in Svelte under AGPL-3.0; Spark is written in Java under Apache-2.0. cobalt has attracted 9% as many forks as stars, Spark 73%. Spark was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 1 topic tag (collaboration), so they are genuine substitutes rather than adjacent tools.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
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Side by side
| cobalt | Spark | |
|---|---|---|
| GitHub stars | ★ 46K | ★ 606 |
| License | AGPL-3.0 | Apache-2.0 |
| Written in | Svelte | Java |
| Last push | 2026-04-06 | 2026-11-01 |
| Forks | ⑂ 4.0K | ⑂ 445 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick cobalt if
- You weight community size — 46K stars and counting
- You want the AGPL-3.0 license terms
- Your stack matches Svelte
- You value the larger contributor base for long-term maintenance
pick Spark if
- You want the Spark feature set and don't need the biggest community
- You prefer the Apache-2.0 license terms
- Your stack matches Java
- You evaluated both and Spark fits your workflow better
About cobalt
best way to save what you love cobalt.tools 💬 community discord server 🐦 twitter 🦋 bluesky cobalt is a media downloader that doesn't piss you off. it's friendly, efficient, and doesn't have ads, trackers, paywalls or other nonsense. paste the link, get the file, move on. that simple, just how it should be. cobalt monorepo this monorepo includes source code for api, frontend, and related packages: api tree & readme web tree & readme packages tree it also includes documentation in the docs tree: how to run a cobalt instance how to protect a cobalt instance cobalt api instance environment variables cobalt api…
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About Spark
Spark ===== [Spark] is an Open Source, cross platform IM client optimized for businesses and organizations. Group Chat In line Spell Checking End to end (E2E) Message Encryption with OTR. Tabbed Conversations File Transfer Screen Capture Sharing Message translations. Combined with the [Openfire] server, [Spark] is the easiest and best alternative to using unsecure public IM networks. [Spark] an [Ignite Realtime] community project. Resources Translation: Documentation: Community: Bug Tracker: Nightly Builds: XMPP compliance: Install Download the last release from the GitHub releases page or nightly build with the…
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Frequently asked questions
Is cobalt or Spark more popular?
cobalt has 45,722 GitHub stars and Spark has 606. cobalt has the larger community by that measure.
Are cobalt and Spark free?
Both are open source. cobalt is licensed under AGPL-3.0 and Spark under Apache-2.0. Neither carries a licence fee.
What is the difference between cobalt and Spark?
cobalt is written in Svelte and Spark in Java. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, cobalt or Spark?
Choose cobalt if you want the larger community (45,722 stars) or its AGPL-3.0 licence terms. Choose Spark if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.