head to head · open source
Mermaid vs ClickHouse
Mermaid has 90,293 GitHub stars, 9,266 forks, 1,781 open issues and last shipped 3 days ago. ClickHouse has 49,951 stars, 8,969 forks, 7,547 open issues and last shipped yesterday. Mermaid leads on adoption by 81% (90,293 vs 49,951 stars). Mermaid is written in TypeScript under MIT; ClickHouse is written in C++ under Apache-2.0. Mermaid has attracted 10% as many forks as stars, ClickHouse 18%. ClickHouse was the more recently maintained of the two, and both are self-hostable with no licence fee.
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
| Mermaid | ClickHouse | |
|---|---|---|
| GitHub stars | ★ 90K | ★ 50K |
| License | MIT | Apache-2.0 |
| Written in | TypeScript | C++ |
| Last push | 2026-09-15 | 2026-09-17 |
| Forks | ⑂ 9.3K | ⑂ 9.0K |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Mermaid if
- You weight community size — 90K stars and counting
- You want the MIT license terms
- Your stack matches TypeScript
- You value the larger contributor base for long-term maintenance
pick ClickHouse if
- You want the ClickHouse feature set and don't need the biggest community
- You prefer the Apache-2.0 license terms
- Your stack matches C++
- You evaluated both and ClickHouse fits your workflow better
About Mermaid
Mermaid is a JavaScript based diagramming tool that renders diagrams from Markdown like text definitions. It lives in the JavaScript/TypeScript ecosystem and operates both in the browser and in Node.js environments. The project’s core purpose is to eliminate the gap between software development and documentation by letting developers write diagrams alongside code, avoiding the rot and overhead of manual diagram maintenance.
read the full Mermaid overview →
About ClickHouse
ClickHouse is an open source, column oriented database management system written in C++ that delivers real time analytical query performance on massive datasets. It operates within the broader data infrastructure ecosystem, serving as a high performance alternative to traditional row oriented databases for OLAP workloads.
read the full ClickHouse overview →
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Frequently asked questions
Is Mermaid or ClickHouse more popular?
Mermaid has 90,293 GitHub stars and ClickHouse has 49,951. Mermaid has the larger community by that measure.
Are Mermaid and ClickHouse free?
Both are open source. Mermaid is licensed under MIT and ClickHouse under Apache-2.0. Neither carries a licence fee.
What is the difference between Mermaid and ClickHouse?
Mermaid is written in TypeScript and ClickHouse in C++. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, Mermaid or ClickHouse?
Choose Mermaid if you want the larger community (90,293 stars) or its MIT licence terms. Choose ClickHouse if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.