# Calibre vs Semaphore UI

> Two self-hosted projects, compared on the numbers selfhost.directory tracks live: score, popularity, release cadence and setup effort.

| | Calibre | Semaphore UI |
|---|---|---|
| Score | 83/100 ✓ | 73/100 |
| Rank in category | #1 of 19 in Ebook Management | #12 of 166 in Developer Tools |
| GitHub stars | 26 269 ✓ | 14 337 |
| Stars, last 30 days | +260 ✓ | +149 |
| Stable releases, 12 months | 18 | 20 ✓ |
| Latest release | v9.17.0 · 23 Oct 2026 ✓ | v2.18.31 · 7 Oct 2026 |
| Setup | Easy ✓ | Easy |
| Official Docker image | No | Yes ✓ |
| License | GPL-3.0 | MIT |
| Main language | Python | Go |

## Which one should you pick?

Calibre scores 83/100 against 73/100 for Semaphore UI, so it is the safer default.

Semaphore UI ships more often: 20 stable releases in the past year, against 18 for Calibre.

## Details

- [Calibre](https://selfhost.directory/project/calibre) (markdown: https://selfhost.directory/project/calibre.md)
- [Semaphore UI](https://selfhost.directory/project/semaphore-ui) (markdown: https://selfhost.directory/project/semaphore-ui.md)

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Source: https://selfhost.directory/compare/calibre-vs-semaphore-ui