# Google Calendar API vs Microsoft Graph Calendar API (slim)

> Google Calendar API has a score of 79.5 (A) against Microsoft Graph Calendar API's 65.6 (B). Both do calendar read. The largest gap is reliability, 25 points. Category scores, facts, verdicts and agent notes side by side.

- Full: https://www.anchorterminal.com/compare/google-calendar-api-vs-microsoft-graph-calendar.md (~1,500 tokens) · this version ~380 tokens · JSON https://www.anchorterminal.com/compare/google-calendar-api-vs-microsoft-graph-calendar.json · canonical https://www.anchorterminal.com/compare/google-calendar-api-vs-microsoft-graph-calendar
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · Updated: 2026-10-05

Google Calendar API has a score of 79.5 (A) against Microsoft Graph Calendar API's 65.6 (B). Both do calendar read. The largest gap is reliability, 25 points.

- Google Calendar API: A 79.5, rank #8 of 452 · https://www.anchorterminal.com/tools/google-calendar-api.min.md
- Microsoft Graph Calendar API: B 65.6, rank #170 of 452 · https://www.anchorterminal.com/tools/microsoft-graph-calendar.min.md
- Pick Google Calendar API for reliability (+25), security & auth (+17), maintenance & community (+11), transparency & trust (+6). Pick Microsoft Graph Calendar API for nothing in particular.

| Category | Google Calendar API | Microsoft Graph Calendar API |
| --- | --- | --- |
| Reliability (16%) | 90 | 65 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 83 | 83 |
| Agent ergonomics (13%) | 91 | 88 |
| Security & auth (14%) | 82 | 65 |
| Payments & pricing (10%) | 35 | 35 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 87 | 76 |
| Transparency & trust (7%) | 79 | 73 |