Landing Page Measurement and Experiments

Live Markdown editor with real-time HTML preview. Supports headings, bold, italic, links, code blocks, tables, and blockquotes.

Calculate percentages in seven modes with visible formulas, strict input validation, signed percentage change, and symmetric percentage difference.

Compare two opaque sRGB colors using WCAG text contrast ratios. See precise ratio estimates, unrounded threshold decisions and clear invalid-color feedback.

Plan approximate samples for an equal-allocation, two-sided comparison of independent binary conversion rates with explicit effect, significance and power.

Compare explicit two-sided power models for one known-variance mean, two independent means or independent binary rates with continuous alpha.

Test categorical goodness of fit or an independent 2×2 outcome table, with actual p-values, Fisher support and labeled proportion-difference intervals.

Compare an unrounded reported p-value with prespecified alpha, without interpreting it as effect size, a confidence interval or hypothesis probability.

Format SQL with an explicit dialect, preserved literals, configurable keyword case and bounded local processing before copying or saving a review.

Validate, losslessly format, and minify JSON while flagging duplicate members and precision-sensitive numbers before parsed tree or XML views.

Calculate linear association from complete paired numeric lists, reject constant inputs and preserve the distinction between correlation and causation.

Score paired actual and predicted numeric values with R² and RMSE, retaining negative scores and explicitly undefined constant-target R².

Summarize actual latency samples and completed-request rates, or add explicit serial stages without inventing P99 or maximum capacity.