---
title: " is not a valid language tag (a11y/html-lang-valid)"
description: "a11y/html-lang-valid: Screen readers and translation tools ignore an invalid lang value and fall back to the user's default language, mispronouncing the…"
canonical: https://void-design.vercel.app/rules/a11y/html-lang-valid
lastModified: 2026-09-16
---
# is not a valid language tag
`a11y/html-lang-valid` · severity **error** · category Accessibility · detected by `void a11y` and `void audit`
## Why it matters
Screen readers and translation tools ignore an invalid lang value and fall back to the user's default language, mispronouncing the content.
## How to fix it
Use a valid BCP 47 language tag such as en, en-GB or pt-BR.
## Example
```
```
## References
- https://dequeuniversity.com/rules/axe/4.13/html-lang-valid
## More accessibility rules
`void a11y` reports 48 rules in this category. WCAG 2.2 AA through axe-core, plus checks axe can't do alone: visible keyboard focus, 24/44px target size on mobile, 320px reflow and disabled zoom.
- `select-name` Select element has no accessible name — [a11y/select-name](https://void-design.vercel.app/rules/a11y/select-name)
- `input-button-name` Input button has no accessible name — [a11y/input-button-name](https://void-design.vercel.app/rules/a11y/input-button-name)
- `input-image-alt` Image button has no alt text — [a11y/input-image-alt](https://void-design.vercel.app/rules/a11y/input-image-alt)
- `html-has-lang` has no lang attribute — [a11y/html-has-lang](https://void-design.vercel.app/rules/a11y/html-has-lang)
- `document-title` Page has no — [a11y/document-title](https://void-design.vercel.app/rules/a11y/document-title)
- `landmark-one-main` Page has no <main> landmark — [a11y/landmark-one-main](https://void-design.vercel.app/rules/a11y/landmark-one-main)
- `region` Content is outside landmark regions — [a11y/region](https://void-design.vercel.app/rules/a11y/region)
- `landmark-unique` Landmarks are not uniquely identifiable — [a11y/landmark-unique](https://void-design.vercel.app/rules/a11y/landmark-unique)
Detected by `void a11y` and `void audit`. Explain it in a terminal: `void rules a11y/html-lang-valid`