CSS Validator — developer utilities, encoders and data format tools
CSS Validator is a free browser-based tool that checks your CSS code for syntax errors and common style issues. It flags unbalanced braces, detects unnecessary units on zero values such as 0px, and warns you when !important is overused. Use it to clean up stylesheets before you deploy.
Category: Developer Tools
About this tool
What Is CSS Validator? CSS Validator is a browser-based tool for Validate CSS code and find errors. This guide explains the result, the calculation or processing method, and correct usage. Calculation or Processing Method The tool applies the operation described in its interface: Validate CSS code and find errors. Processing method: The tool produces the result using a processing method appropriate to the input data type. How to Use It Open the tool and choose the required unit, mode, or options. Enter values or paste text into the input fields. Review the result, copy it, or continue with a related tool. Important Notes Use consistent units and verify values before calculating. Incomplete or invalid input can produce an incomplete result. Related Tools Tools that support the same workflow: JSON Formatter — Format, validate, and minify JSON with syntax highlighting. Base64 Encoder/Decoder — Encode and decode text or files in Base64. Hash Generator — Generate MD5, SHA-1, SHA-256 hashes for text. Frequently Asked Questions How does CSS Validator work? The tool processes input according to its purpose: Validate CSS code and find errors. Are CSS Validator results accurate? Results are deterministic when input and units are correct.