head to head · open source
cobalt vs blocksuite
cobalt has 43,316 GitHub stars, 3,798 forks, 269 open issues and last shipped 6 months ago. blocksuite has 6,016 stars, 563 forks, 196 open issues and last shipped 3 days ago. cobalt leads on adoption by 620% (43,316 vs 6,016 stars). cobalt is written in Svelte under AGPL-3.0; blocksuite is written in TypeScript under MPL-2.0. cobalt has attracted 9% as many forks as stars, blocksuite 9%. blocksuite 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 | blocksuite | |
|---|---|---|
| GitHub stars | ★ 43K | ★ 6.0K |
| License | AGPL-3.0 | MPL-2.0 |
| Written in | Svelte | TypeScript |
| Last push | 2026-04-06 | 2026-09-15 |
| Forks | ⑂ 3.8K | ⑂ 563 |
| 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 blocksuite if
- You want the blocksuite feature set and don't need the biggest community
- You prefer the MPL-2.0 license terms
- Your stack matches TypeScript
- You evaluated both and blocksuite 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 blocksuite
BlockSuite is an MPL 2.0 licensed TypeScript toolkit for building block based editors and collaborative applications, intended for developers who need to embed, extend, or compose rich content editing rather than adopt a finished product.
read the full blocksuite overview →
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Frequently asked questions
Is cobalt or blocksuite more popular?
cobalt has 43,316 GitHub stars and blocksuite has 6,016. cobalt has the larger community by that measure.
Are cobalt and blocksuite free?
Both are open source. cobalt is licensed under AGPL-3.0 and blocksuite under MPL-2.0. Neither carries a licence fee.
What is the difference between cobalt and blocksuite?
cobalt is written in Svelte and blocksuite 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 blocksuite?
Choose cobalt if you want the larger community (43,316 stars) or its AGPL-3.0 licence terms. Choose blocksuite if its feature set, stack or MPL-2.0 licence fits better. Both are self-hostable.