head to head · open source
Signal vs certstrap
Signal has 29,568 GitHub stars, 6,933 forks, 498 open issues and last shipped 4 days ago. certstrap has 2,462 stars, 212 forks, 32 open issues and last shipped yesterday. Signal leads on adoption by 1,101% (29,568 vs 2,462 stars). Signal is written in Kotlin under AGPL-3.0; certstrap is written in Go under Apache-2.0. Signal has attracted 23% as many forks as stars, certstrap 9%. certstrap 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
| Signal | certstrap | |
|---|---|---|
| GitHub stars | ★ 30K | ★ 2.5K |
| License | AGPL-3.0 | Apache-2.0 |
| Written in | Kotlin | Go |
| Last push | 2026-10-30 | 2026-11-02 |
| Forks | ⑂ 6.9K | ⑂ 212 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Signal if
- You weight community size — 30K stars and counting
- You want the AGPL-3.0 license terms
- Your stack matches Kotlin
- You value the larger contributor base for long-term maintenance
pick certstrap if
- You want the certstrap feature set and don't need the biggest community
- You prefer the Apache-2.0 license terms
- Your stack matches Go
- You evaluated both and certstrap fits your workflow better
About Signal
Signal Android Signal is a simple, powerful, and secure messenger that uses your phone's data connection (WiFi/4G/5G) to communicate securely. Millions of people use Signal every day for free and instantaneous communication anywhere in the world. Send and receive high fidelity messages, participate in HD voice/video calls, and explore a growing set of new features that help you stay connected. Signal’s advanced privacy preserving technology is always enabled, so you can focus on sharing the moments that matter with the people who matter to you. Currently available on the Play Store and signal.org. Also available…
read the full Signal overview →
About certstrap
certstrap A simple certificate manager written in Go, to bootstrap your own certificate authority and public key infrastructure. Adapted from etcd ca. certstrap is a very convenient app if you don't feel like dealing with openssl, its myriad of options or config files. Common Uses certstrap allows you to build your own certificate system: 1. Initialize certificate authorities 2. Create identities and certificate signature requests for hosts 3. Sign and generate certificates Certificate architecture certstrap can init multiple certificate authorities to sign certificates with. Users can make arbitrarily long…
read the full certstrap overview →
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Frequently asked questions
Is Signal or certstrap more popular?
Signal has 29,568 GitHub stars and certstrap has 2,462. Signal has the larger community by that measure.
Are Signal and certstrap free?
Both are open source. Signal is licensed under AGPL-3.0 and certstrap under Apache-2.0. Neither carries a licence fee.
What is the difference between Signal and certstrap?
Signal is written in Kotlin and certstrap in Go. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, Signal or certstrap?
Choose Signal if you want the larger community (29,568 stars) or its AGPL-3.0 licence terms. Choose certstrap if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.