head to head · open source
papermill vs substance
papermill has 6,485 GitHub stars, 462 forks, 196 open issues and last shipped 3 months ago. substance has 2,733 stars, 121 forks, 41 open issues and last shipped 6 months ago. papermill leads on adoption by 137% (6,485 vs 2,733 stars). papermill is written in Python under BSD-3-Clause; substance is written in JavaScript under MIT. papermill has attracted 7% as many forks as stars, substance 4%. papermill was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 1 topic tag (publishing), 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
| papermill | substance | |
|---|---|---|
| GitHub stars | ★ 6.5K | ★ 2.7K |
| License | BSD-3-Clause | MIT |
| Written in | Python | JavaScript |
| Last push | 2026-07-06 | 2026-04-02 |
| Forks | ⑂ 462 | ⑂ 121 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick papermill if
- You weight community size — 6.5K stars and counting
- You want the BSD-3-Clause license terms
- Your stack matches Python
- You value the larger contributor base for long-term maintenance
pick substance if
- You want the substance feature set and don't need the biggest community
- You prefer the MIT license terms
- Your stack matches JavaScript
- You evaluated both and substance fits your workflow better
About papermill
Papermill is a Python tool published under the BSD 3 Clause licence by the nteract project that parameterizes, executes, and analyzes Jupyter notebooks, and it is aimed at teams who need to run the same notebook repeatedly with different inputs inside data pipelines.
read the full papermill overview →
About substance
Substance is a JavaScript library for web based content editing. It lives in the JavaScript and Content & Publishing / Publishing ecosystem, and it is distributed under the MIT license. The README describes it as a library that provides building blocks for realizing custom text editors and web based publishing systems, and it was developed to power the online editing platform Substance.
read the full substance overview →
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Frequently asked questions
Is papermill or substance more popular?
papermill has 6,485 GitHub stars and substance has 2,733. papermill has the larger community by that measure.
Are papermill and substance free?
Both are open source. papermill is licensed under BSD-3-Clause and substance under MIT. Neither carries a licence fee.
What is the difference between papermill and substance?
papermill is written in Python and substance in JavaScript. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, papermill or substance?
Choose papermill if you want the larger community (6,485 stars) or its BSD-3-Clause licence terms. Choose substance if its feature set, stack or MIT licence fits better. Both are self-hostable.