# W3C CSS Validation Service

**Canonical:** https://apis.io/apis/css/w3c-css-validation-service/  
**Provider:** CSS (Cascading Style Sheets) — https://apis.io/providers/css/  
**Base URL:** https://jigsaw.w3.org/css-validator/validator  
**Documentation:** https://jigsaw.w3.org/css-validator/

W3C CSS Validation Service is published by [CSS (Cascading Style Sheets)](https://apis.io/providers/css/) on the [APIs.io](https://apis.io/) network. Tagged areas include CSS, Validation, Conformance, W3C, and SOAP. The published artifact set on APIs.io includes API documentation, an API reference, a getting-started guide, authentication docs, and rate-limit docs.

The W3C's public CSS validator, exposed as a web service. A single safe operation checks a stylesheet — supplied either as a URL or as inline text — against a chosen CSS profile and returns the errors and warnings found, in XHTML, plain text, SOAP 1.2 or JSON. It is anonymous and free, and W3C publishes a WSDL 2.0 description of the SOAP interface. This is the only callable HTTP surface associated with CSS; CSS itself is a specification, not a hosted service.

## Machine-readable artifacts (13)

- **WSDL** — https://raw.githubusercontent.com/api-evangelist/css/refs/heads/main/wsdl/css-validator.wsdl
- **Documentation** — https://jigsaw.w3.org/css-validator/documentation.html
- **APIReference** — https://jigsaw.w3.org/css-validator/api.html
- **GettingStarted** — https://jigsaw.w3.org/css-validator/manual.html
- **Authentication** — https://raw.githubusercontent.com/api-evangelist/css/refs/heads/main/authentication/css-authentication.yml
- **RateLimits** — https://raw.githubusercontent.com/api-evangelist/css/refs/heads/main/rate-limits/css-rate-limits.yml
- **Conventions** — https://raw.githubusercontent.com/api-evangelist/css/refs/heads/main/conventions/css-conventions.yml
- **ErrorCatalog** — https://raw.githubusercontent.com/api-evangelist/css/refs/heads/main/errors/css-problem-types.yml
- **DataModel** — https://raw.githubusercontent.com/api-evangelist/css/refs/heads/main/data-model/css-data-model.yml
- **Sandbox** — https://raw.githubusercontent.com/api-evangelist/css/refs/heads/main/sandbox/css-sandbox.yml
- **CLI** — https://raw.githubusercontent.com/api-evangelist/css/refs/heads/main/cli/css-cli.yml
- **SourceCode** — https://github.com/w3c/css-validator
- **APIsJSON** — https://raw.githubusercontent.com/api-evangelist/css/refs/heads/main/apis.yml

## Tags

CSS, Validation, Conformance, W3C, SOAP

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/apis/css/w3c-css-validation-service/). The API's provider profile, Kin Score and agent-readiness rating are at https://apis.io/providers/css/.