Check a declaration-list migration in its receiving build

Translate a declaration list rather than an entire stylesheet

This converter accepts a bounded list of CSS declarations separated by semicolons. Its result is a candidate class string for a Tailwind 3 project using the default utility theme, with arbitrary properties where a direct preset is not used. It does not infer which HTML elements a selector targets, migrate a component tree or preserve a stylesheet's complete cascade automatically. Paste one intended element's declarations at a time. Keep the source nearby so every declaration has an accountable destination. Unsupported input should produce an explanation, not a shortened class list that silently discards part of your design.

Reproduce an owned packing-label component

For a fictional packing label, enter display: flex; align-items: center; padding: 16px; color: #ffffff; background-color: #3b82f6;. Convert the declarations and inspect the generated flex, alignment, padding and color utilities. In a default Tailwind 3 build with a 16-pixel root font, the receiving element should have flex display, centered cross-axis alignment, 16-pixel padding, white text and the supplied blue background. Compile the actual emitted class string and inspect computed styles. A class name that looks plausible is insufficient evidence that the receiving compiler found it or that your project's theme gives it the expected value.

Inspect arbitrary properties without lowercasing identifiers

A supported value outside the preset table becomes an arbitrary property such as [padding:15px]. Spaces are encoded for the class token, while existing underscores are escaped so they retain their intended meaning. The converter preserves case in values such as var(--Brand), because custom-property names can be case-sensitive. A 32-pixel font size uses an explicit arbitrary property rather than pretending that the default text-3xl size is 32 pixels. Typography presets can also set line-height, so inspect their accompanying styles. These outputs require the receiving Tailwind version and content scanner to understand the syntax. Keep the full literal class available to that scanner; dynamically constructing fragments can prevent generation.

Use the supported property contract

Direct mappings cover selected display, flex alignment, gap, typography, spacing, border-width, radius and color declarations. The arbitrary-value path supports the same property set plus width and height. This is not a claim that every CSS property is translated. An unsupported property is reported by name and prevents a partial successful result. Selectors, nested rules and at-rules belong in a stylesheet and are rejected here. Comments can separate declarations, but a comment does not supply a responsive breakpoint or hover condition. Move media-query and state behavior into an explicitly designed component rather than assuming the converter inferred it.

Resolve duplicates and shorthand deliberately

When the exact same property occurs more than once, important declarations take priority over normal declarations; the last declaration at the strongest importance level supplies the candidate output. Combining a padding or margin shorthand with one of its longhands is rejected for manual review. That combination can depend on source order, whereas the order in which utility CSS is generated is not established simply by rearranging class names in HTML. Important declarations keep an important marker in the candidate class. This limited treatment is not a general cascade solver: specificity, inheritance, layers and competing external styles must still be considered in the receiving project.

Treat browser acceptance as one check

The page checks supported declaration values with the browser's CSS support interface before emitting them. That detects many invalid values in the browser running the tool, but it does not certify every target browser or an older embedded email renderer. Custom-property substitution can defer whether a value ultimately makes sense. A value accepted for one property can still create an unusable layout with real content. Test both the source rule and generated classes on the same receiving element and inspect the computed values that matter. Include long text, focus states and constrained width in that acceptance exercise.

Stay within a small conversion scope

Input is limited to 50,000 UTF-16 text units and between one and one hundred declarations. Empty input has no class result. These bounds keep the operation focused on one component rather than an arbitrary stylesheet import. Editing the source clears the previous output, and clipboard errors are reported separately from conversion errors. There is no project upload, dependency installation, generated HTML document or stylesheet download on this page. The Load CSS Sample control is an illustration of the supported declaration-list shape, not a template for all projects or evidence about the content of your own repository.

Check the receiving theme and generated CSS

A preset spacing utility is expressed relative to Tailwind's theme and can differ from a fixed pixel declaration when the root font or theme changes. For the packing-label example, repeat the computed-style check after changing the root font to see which preset-based dimensions move. Where exact fixed units are essential, review an explicit arbitrary declaration in the receiving project instead of assuming a default preset is universally equivalent. Tailwind version changes can also affect utility naming and interpretation. Keep the generated CSS, compiler version and test element with the source declarations so the conversion can be reviewed later.

Keep conversion and publication separate

Parsing and class generation run locally in the browser without a conversion API. Ordinary site assets and services remain governed by the site's Privacy Policy. The tool does not save a conversion history or publish code into your project. Copy only a current successful result and retain the original declaration list for comparison. A successful conversion is an aid to implementation, not a guarantee of responsive design, accessibility, smaller bundles or ranking improvement. If the receiving layout differs, first inspect emitted utility rules, theme settings and competing styles rather than adding unrelated classes until a screenshot happens to look similar.

References: Tailwind 3 custom styles

CSS to Tailwind: Declaration List Converter