Blog

Screenshot testing, or testing through screen captures, is the most direct approach to visual testing: you capture the rendered state of a page or component, compare it against a reference capture, and flag any difference. This method, sometimes called UI snapshot testing, appeals through its conceptual simplicity and its cross-cutting coverage — a single screenshot verifies in one shot the layout, colors, typography, images and component states. In return, it requires real discipline around rendering determinism: fonts loaded before capture, frozen data, animations disabled, stable viewport.

The articles gathered here detail the best practices: choice between full-page and per-component screenshots, handling of dynamic regions (dates, counters, carousels), naming and versioning strategies for baseline screenshots, comparison with other approaches like DOM snapshots or automated accessibility testing. We also cover the honest limits of the method, particularly the noise generated by cross-OS rendering and the cost of maintaining baselines on an active design system. Delta-QA is built on this capture mechanic, with a focus on full web pages rather than isolated components; the goal of this page is to help everyone choose the tool and granularity suited to their context.