z-index Manager

The z-index Manager is a free browser-based tool for designing and maintaining consistent z-index layer hierarchies in your CSS. Instead of scattering magic numbers across your stylesheets and hoping they don't collide, you can define all your z-index layers in one place, visualize their stacking order, and export a clean scale system in whatever format your project requires.

Managing z-index values is one of the most common sources of CSS bugs. Teams often resort to random large numbers (z-index: 99999) to force elements above others, which creates an unmaintainable mess. This tool solves the problem by letting you define a deliberate, well-structured layer system. You add named layers, assign z-index values, and the tool shows you the visual stacking order and highlights any conflicts where two layers share the same value.

The tool includes built-in presets for popular frameworks including Bootstrap's z-index scale (1000–1080), Material UI's elevation system (1050–1500), Tailwind's default scale (0–50), and a custom linear scale. You can load any preset as a starting point and customize it to match your project's needs. Each layer can also be marked as creating a new stacking context, which is critical for understanding how CSS stacking actually works in practice.

Output is available in four formats: CSS custom properties (variables), Sass/SCSS maps with a helper function, JavaScript objects, and TypeScript objects with a const assertion and type export. This covers virtually any frontend stack. If you use a design token system or need to keep your z-index scale in sync between CSS and JavaScript, the multi-format output makes that seamless.

The conflict detector automatically highlights layers with overlapping z-index values so you can spot problems before they reach production. The visual stack preview shows layers sorted by their z-index value with a 3D-perspective view of how they stack relative to each other.

All processing runs entirely in your browser. No data is sent to any server. You can safely design z-index systems for proprietary projects without any privacy concerns. Combine this tool with the px ↔ rem Converter for comprehensive CSS unit management, or use the CSS Layout Generator to build Flexbox and Grid layouts alongside your z-index system.

1. Load a preset or start from scratch by selecting a z-index preset (Bootstrap, Material UI, Tailwind, or Custom Linear) from the dropdown.
2. Add layers by entering a name (e.g., "modal"), a z-index value (e.g., 1050), and optionally toggling "Stacking ctx" if the layer creates a new stacking context. Press Add or hit Enter.
3. Edit layers inline by clicking on any layer's name or z-index value. Toggle the "ctx" button to mark a layer as creating a stacking context.
4. Reorder layers by dragging the grip handle on the left side of each layer row.
5. Check for conflicts — the tool automatically highlights layers with duplicate z-index values in orange. Resolve conflicts by adjusting values.
6. Review the visual stack — the stacking preview shows all layers sorted by z-index in a 3D-perspective view with stacking context indicators.
7. Select your preferred output format (CSS Variables, Sass/SCSS, JS, or TS) and click Copy or press Ctrl+Shift+C to copy the generated code.