Appointment Scheduling Software · reliability comparison
Cal.com vs Sign In Scheduling (formerly 10to8): which is more reliable? (2026)
Sign In Scheduling (formerly 10to8) is more reliable than Cal.com, scoring 100.0 vs 86.2 out of 100. Over the last 90 days Cal.com reported 3 incidents and Sign In Scheduling (formerly 10to8) reported 0, with effective uptime of 100% and 100% respectively.
Data updated Nov 1, 2026 · How we score
VS
| Metric | Cal.com | Sign In Scheduling (formerly 10to8) |
|---|---|---|
| Reliability score | 86.2 | 100.0 |
| Rank (scheduling apps) | #6 | #4 |
| Uptime (90 days) | 100% | 100% |
| Incidents (90 days) | 3 | 0 |
| Partial / major outages | 2 | 0 |
| Avg time to resolve | — | — |
| Outages we detected | 0 | 0 |
| Transparency score | 100/100 | 100/100 |
Where Cal.com and Sign In Scheduling (formerly 10to8) differ
- Sign In Scheduling (formerly 10to8) reported no incidents in the last 90 days, while Cal.com reported 3.
- Cal.com had 2 partial or major outages, compared with 0 for Sign In Scheduling (formerly 10to8).
90-day uptime
Cal.com
Sign In Scheduling (formerly 10to8)
- No incidents
- Degraded
- Partial outage
- Major outage
- No data
Recent Cal.com incidents
- Partial outageOct 24, 2026 · resolved (duration not published)
Resolved - Identified - Issues with Enterprise SAML Authentication
- Degraded performanceSep 15, 2026 · resolved (duration not published)
- Major outageAug 31, 2026 · resolved (duration not published)
Resolved - Major outage: We resolved an issue impacting the API - https://api.cal.com/
Recent Sign In Scheduling (formerly 10to8) incidents
No incidents reported by Sign In Scheduling (formerly 10to8) in the last 90 days.
Full Sign In Scheduling (formerly 10to8) reliability report →
Other scheduling apps to consider
- Calendly · #1 · 100% uptime
- Doodle · #2 · 100% uptime
- SavvyCal · #3 · 100% uptime
- YouCanBookMe · #5 · 100% uptime
See the full most reliable appointment scheduling software ranking →