Overview
Detect and validate VAST XML on any page. IAB VAST 2.0–4.3, SIMID, VPAID. 121 rules. Wrapper chains. By vastlint.org.
vastlint validates VAST XML ad tags directly in your browser — no copy-pasting into external tools. When you open a VAST XML URL, vastlint automatically: • Highlights every error, warning, and info issue inline on the correct line • Draws squiggly underlines under the offending XML element • Shows the rule ID and severity inline with the code • Displays the full error message and spec reference on hover • Links every rule to vastlint.org/docs for detailed fix guidance Supports VAST 2.0, 3.0, 4.0, 4.1, and 4.2. Built on vastlint — a fast, spec-accurate VAST validator written in Rust and compiled to WebAssembly. All validation runs locally in your browser. No data is sent to any server. Open source: github.com/aleksUIX/vastlint
Details
- Version0.4.22
- UpdatedJune 10, 2026
- Size243KiB
- LanguagesEnglish (United States)
- Developer
Email
inbox@vastlint.org - Non-traderThis developer has not identified itself as a trader. For consumers in the European Union, please note that consumer rights do not apply to contracts between you and this developer.
Privacy
This developer declares that your data is
- Not being sold to third parties, outside of the approved use cases
- Not being used or transferred for purposes that are unrelated to the item's core functionality
- Not being used or transferred to determine creditworthiness or for lending purposes
Support
For help with questions, suggestions, or problems, visit the developer's support site
