Comparing
2KB immutable date time library alternative to Moment.js with the same modern API
End-to-end browser testing framework that runs tests in Chromium, Firefox, and WebKit.
| Metric | dayjs | @playwright/test |
|---|---|---|
| Ecosystem | npm | npm |
| Difficulty | Intermediate | Intermediate |
| Weekly downloads | 43.9M↑ | 5.2M |
| Latest version | v1.11.20 | v1.47.2 |
| Recipes | 1 | 3↑ |
dayjs only
Shared
@playwright/test only
Use Day.js when you need date parsing, formatting, arithmetic (add/subtract days/months), or comparisons in browser code where bundle size matters. Its plugin system covers timezones, relative time ('3 hours ago'), duration, and ISO weeks.
Critical user flows (login, checkout, onboarding), cross-browser compatibility checks, visual regression testing, scraping JS-rendered content, accessibility audits.
For complex timezone-aware calendar applications, consider Temporal (the upcoming TC39 proposal) or date-fns with explicit timezone handling. Day.js's plugin system can grow large if you need many features.
Unit or integration testing (Vitest/Jest is faster). Tests that don't need a real browser. Simple API testing (use supertest or fetch).
dayjs
@playwright/test