Cal.com
Semaphore
| Feature | Cal.com | Semaphore |
|---|---|---|
| Pricing | Free / from $12/mo | Free / from $10/mo |
| Free Plan | ✓ Yes | ✓ Yes |
| Rating | 4.4 / 5 | 4.3 / 5 |
| Best For | developers, startups, agencies, privacy-conscious-teams | development-teams, open-source-projects, startups, monorepo-users |
| Founded | 2021 | 2012 |
| Scheduling | ✓ | ✗ |
| Self Hosting | ✓ | ✗ |
| Api | ✓ | ✗ |
| Webhooks | ✓ | ✗ |
| Round Robin | ✓ | ✗ |
| Collective Scheduling | ✓ | ✗ |
| Embed | ✓ | ✗ |
| Parallel Pipelines | ✗ | ✓ |
| Test Reports | ✗ | ✓ |
| Secrets Management | ✗ | ✓ |
| Docker Support | ✗ | ✓ |
| Caching | ✗ | ✓ |
| Notifications | ✗ | ✓ |
✓ Cal.com Pros
- Open-source and self-hostable
- Unlimited event types on free plan
- Full API and webhook access
- White-label and embed options
✗ Cal.com Cons
- Self-hosting requires technical setup
- Fewer integrations than Calendly
- UI less polished than Calendly
✓ Semaphore Pros
- Extremely fast build times
- Generous free tier for open source
- Easy YAML-based configuration
- Built-in secrets management
✗ Semaphore Cons
- Smaller community than GitHub Actions
- Limited marketplace for pre-built steps
- Debugging failed builds can be tricky
The Verdict
Cal.com is built for developers and startups, with a focus on scheduling and self-hosting. Semaphore targets development teams and open source projects and leads with parallel-pipelines and test-reports.
Pricing is close: Semaphore starts at $10/mo versus $12/mo for Cal.com — not a deciding factor on its own.
Both offer free plans, so you can test each with your real workflow before committing to a subscription.
Feature-wise, Cal.com offers broader built-in capabilities (7 features vs 6), while Semaphore takes a more focused approach — which can mean a simpler, faster onboarding experience.
Both tools are a solid fit for startups — in those cases, the decision often comes down to workflow style and how your team prefers to organize work.
This is a genuinely close comparison. If you can, sign up for both free trials (where available) and run a one-week test with your actual team tasks before deciding.