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Visual testing, in depth
Practical guides on visual regression testing, screenshot diffing, and catching UI changes before your users do, including visual testing from your AI coding assistant.
What Is an MCP Server? A Plain-Language Guide for Developers
An MCP server is a program that gives an AI assistant new tools. With 10,000+ public servers now live, here is how the Model Context Protocol works.
SSIM vs Pixel Diff: A 40-Site Benchmark of Our Engine
SSIM is said to eliminate the false positives that plague pixel diffing. We benchmarked both on 40 real sites with our own engine. The result surprised us.
From Prompt to Verified UI: An MCP Workflow Case Study
How we use our own MCP server to catch visual regressions in AI-generated code, walked through one real change to our pricing page that a prompt quietly broke.
How Visual Diffing Works: Pixel, SSIM, Perceptual Comparison
The complete guide to image diffing for visual regression testing: pixel diffs in YIQ, SSIM structural comparison (cited 50,000+ times), perceptual hashing.
How to Eliminate False Positives in Visual Testing
Visual tests fail for reasons that are not bugs: animations, font swaps, dynamic content, cross-OS rendering. Seven techniques to cut false positives.
SSIM vs Pixel Diff: Which Catches Real Regressions?
Pixel diffing flags anti-aliasing and font noise as failures. SSIM, from a paper cited 50,000+ times, compares structure instead. When to use each.
Percy Alternatives for Teams Tired of Per-Screenshot Pricing
Percy bills per screenshot: one snapshot across 2 browsers and 3 widths counts as 6. A fair look at the alternatives, from flat-rate to free open-source.
Visual Testing for AI Coding Assistants: The MCP Guide
84% of developers now use AI coding tools. Add visual regression testing to Claude Code, Cursor, and Windsurf via MCP so AI-generated UI changes get checked.
Visual Regression Testing in Claude Code: A Complete Guide
Catch unintended UI changes without leaving your editor. A step-by-step guide to visual regression testing in Claude Code using an MCP server with eight visual tools.