Argos vs BackstopJS: licensing, GitHub activity, and what each is actually for. Neutral comparison, no paid rankings.
Argos: Open source. 636 GitHub stars. Self-hostable visual testing platform that snapshots UI in CI, diffs against baselines with flake stabilization, and surfaces changes as PR comments.
BackstopJS: Open source. 7,186 GitHub stars. Self-hosted visual regression tool that captures headless-Chrome screenshots and diffs them pixel-by-pixel against approved baselines.