Comparison
Unit and end-to-end tests
Unit tests examine a small behavior in isolation, while end-to-end tests exercise a broader user workflow through connected parts of an application.
At a glance
- Unit scope
- A focused behavior with controlled inputs
- End-to-end scope
- A user workflow across application boundaries
Overview
Unit tests examine a small behavior in isolation, while end-to-end tests exercise a broader user workflow through connected parts of an application. They provide different evidence, so a testing strategy chooses the scope that can reveal the failure being investigated.
What differs
A unit test can pinpoint a small contract quickly. A browser workflow can reveal failures in navigation, rendering, requests, or integration that are invisible when the underlying units are tested separately.
Choose by the task
Use the smallest scope that can expose the relevant mistake. Add workflow coverage when correctness depends on connected systems, and keep its setup and assertions tied to observable user outcomes.
Common confusion
Passing unit tests does not prove that a deployed application launches or that a user can finish a task. Conversely, one successful browser path does not cover every important input or failure boundary.
Sources and review
MOOR's explanatory text is supported by the following source links.
- Getting started — Vitest
- End-to-end testing introduction — Playwright