head to head · open source
cobalt vs partykit
cobalt has 43,316 GitHub stars, 3,798 forks, 269 open issues and last shipped 6 months ago. partykit has 5,710 stars, 200 forks, 93 open issues and last shipped 8 months ago. cobalt leads on adoption by 659% (43,316 vs 5,710 stars). cobalt is written in Svelte under AGPL-3.0; partykit is written in TypeScript under MIT. cobalt has attracted 9% as many forks as stars, partykit 4%. cobalt 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 | partykit | |
|---|---|---|
| GitHub stars | ★ 43K | ★ 5.7K |
| License | AGPL-3.0 | MIT |
| Written in | Svelte | TypeScript |
| Last push | 2026-04-06 | 2026-01-29 |
| Forks | ⑂ 3.8K | ⑂ 200 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick cobalt if
- You weight community size — 43K 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 partykit if
- You want the partykit feature set and don't need the biggest community
- You prefer the MIT license terms
- Your stack matches TypeScript
- You evaluated both and partykit fits your workflow better
About cobalt
cobalt is a media downloader built around a single promise: paste a link, get the file, move on. It is a monorepo containing the source for an API, a web frontend, and related packages, written primarily in Svelte and TypeScript. The project lives in the modern web and JavaScript ecosystem, and its public surface is hosted at cobalt.tools, while the full codebase is published under the AGPL 3.0 license.
read the full cobalt overview →
About partykit
PartyKit is an open source, MIT licensed TypeScript framework and cloud platform for building multiplayer and real time applications, aimed at developers who want to add collaborative or live features without operating real time infrastructure themselves.
read the full partykit overview →
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Frequently asked questions
Is cobalt or partykit more popular?
cobalt has 43,316 GitHub stars and partykit has 5,710. cobalt has the larger community by that measure.
Are cobalt and partykit free?
Both are open source. cobalt is licensed under AGPL-3.0 and partykit under MIT. Neither carries a licence fee.
What is the difference between cobalt and partykit?
cobalt is written in Svelte and partykit in TypeScript. 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 partykit?
Choose cobalt if you want the larger community (43,316 stars) or its AGPL-3.0 licence terms. Choose partykit if its feature set, stack or MIT licence fits better. Both are self-hostable.