diff --git a/Cargo.lock b/Cargo.lock
index b9df198a9..d579f0873 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1098,6 +1098,12 @@ dependencies = [
"wasm-bindgen",
]
+[[package]]
+name = "language-tags"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d4345964bb142484797b161f473a503a434de77149dd8c7427788c6e13379388"
+
[[package]]
name = "lazy_static"
version = "1.4.0"
@@ -1682,6 +1688,7 @@ dependencies = [
"dashmap",
"insta",
"itertools 0.12.0",
+ "language-tags",
"lazy_static",
"memchr",
"miette",
diff --git a/Cargo.toml b/Cargo.toml
index 2456b2d3e..c5594d22a 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -135,6 +135,7 @@ trustfall = { version = "0.6.1" }
insta = { version = "1.34.0", features = ["glob"] }
codspeed-criterion-compat = { version = "2.3.3", default-features = false }
glob = { version = "0.3.1" }
+language-tags = { version = "0.3.2" }
[profile.release.package.oxc_wasm]
opt-level = 'z'
diff --git a/crates/oxc_linter/Cargo.toml b/crates/oxc_linter/Cargo.toml
index 475e34d25..1ddf5b32e 100644
--- a/crates/oxc_linter/Cargo.toml
+++ b/crates/oxc_linter/Cargo.toml
@@ -31,16 +31,17 @@ oxc_formatter = { workspace = true }
oxc_index = { workspace = true }
oxc_resolver = { version = "1.0.1" }
-rayon = { workspace = true }
-lazy_static = { workspace = true } # used in oxc_macros
-serde_json = { workspace = true }
-regex = { workspace = true }
-rustc-hash = { workspace = true }
-phf = { workspace = true, features = ["macros"] }
-num-traits = { workspace = true }
-itertools = { workspace = true }
-dashmap = { workspace = true }
-convert_case = { workspace = true }
+rayon = { workspace = true }
+lazy_static = { workspace = true } # used in oxc_macros
+serde_json = { workspace = true }
+regex = { workspace = true }
+rustc-hash = { workspace = true }
+phf = { workspace = true, features = ["macros"] }
+num-traits = { workspace = true }
+itertools = { workspace = true }
+dashmap = { workspace = true }
+convert_case = { workspace = true }
+language-tags = { workspace = true }
rust-lapper = "1.1.0"
once_cell = "1.19.0"
diff --git a/crates/oxc_linter/src/rules.rs b/crates/oxc_linter/src/rules.rs
index cfbe06b39..80b54221d 100644
--- a/crates/oxc_linter/src/rules.rs
+++ b/crates/oxc_linter/src/rules.rs
@@ -236,6 +236,7 @@ mod jsx_a11y {
pub mod html_has_lang;
pub mod iframe_has_title;
pub mod img_redundant_alt;
+ pub mod lang;
pub mod no_access_key;
pub mod no_aria_hidden_on_focusable;
pub mod no_autofocus;
@@ -457,6 +458,7 @@ oxc_macros::declare_all_lint_rules! {
jsx_a11y::aria_props,
jsx_a11y::heading_has_content,
jsx_a11y::html_has_lang,
+ jsx_a11y::lang,
jsx_a11y::iframe_has_title,
jsx_a11y::img_redundant_alt,
jsx_a11y::no_access_key,
diff --git a/crates/oxc_linter/src/rules/jsx_a11y/lang.rs b/crates/oxc_linter/src/rules/jsx_a11y/lang.rs
new file mode 100644
index 000000000..f2b4e107d
--- /dev/null
+++ b/crates/oxc_linter/src/rules/jsx_a11y/lang.rs
@@ -0,0 +1,159 @@
+use language_tags::LanguageTag;
+use oxc_ast::{
+ ast::{
+ JSXAttributeItem, JSXAttributeValue, JSXElementName, JSXExpression, JSXExpressionContainer,
+ },
+ AstKind,
+};
+use oxc_diagnostics::{
+ miette::{self, Diagnostic},
+ thiserror::Error,
+};
+use oxc_macros::declare_oxc_lint;
+use oxc_span::Span;
+
+use crate::{
+ context::LintContext,
+ rule::Rule,
+ utils::{get_element_type, has_jsx_prop_lowercase},
+ AstNode,
+};
+
+#[derive(Debug, Error, Diagnostic)]
+#[error("eslint-plugin-jsx-a11y(lang): Lang attribute must have a valid value.")]
+#[diagnostic(severity(warning), help("Set a valid value for lang attribute."))]
+struct LangDiagnostic(#[label] pub Span);
+
+#[derive(Debug, Default, Clone)]
+pub struct Lang;
+
+declare_oxc_lint!(
+ /// ### What it does
+ ///
+ /// The lang prop on the element must be a valid IETF's BCP 47 language tag.
+ ///
+ /// ### Why is this bad?
+ ///
+ /// If the language of a webpage is not specified as valid,
+ /// the screen reader assumes the default language set by the user.
+ /// Language settings become an issue for users who speak multiple languages
+ /// and access website in more than one language.
+ ///
+ ///
+ /// ### Example
+ ///
+ /// // good
+ /// ```javascript
+ ///
+ ///
+ /// ```
+ ///
+ /// // bad
+ /// ```javascript
+ ///
+ ///
+ /// ````
+ ///
+ /// ### Resources
+ /// - [eslint-plugin-jsx-a11y/lang](https://github.com/jsx-eslint/eslint-plugin-jsx-a11y/blob/main/docs/rules/lang.md)
+ /// - [IANA Language Subtag Registry](https://www.iana.org/assignments/language-subtag-registry/language-subtag-registry)
+ Lang,
+ correctness
+);
+
+impl Rule for Lang {
+ fn run<'a>(&self, node: &AstNode<'a>, ctx: &LintContext<'a>) {
+ let AstKind::JSXOpeningElement(jsx_el) = node.kind() else {
+ return;
+ };
+
+ let Some(element_type) = get_element_type(ctx, jsx_el) else {
+ return;
+ };
+
+ if element_type != "html" {
+ return;
+ }
+
+ let JSXElementName::Identifier(identifier) = &jsx_el.name else {
+ return;
+ };
+
+ has_jsx_prop_lowercase(jsx_el, "lang").map_or_else(
+ || ctx.diagnostic(LangDiagnostic(identifier.span)),
+ |lang_prop| {
+ if !is_valid_lang_prop(lang_prop) {
+ if let JSXAttributeItem::Attribute(attr) = lang_prop {
+ ctx.diagnostic(LangDiagnostic(attr.span));
+ }
+ }
+ },
+ );
+ }
+}
+
+fn get_prop_value<'a, 'b>(item: &'b JSXAttributeItem<'a>) -> Option<&'b JSXAttributeValue<'a>> {
+ if let JSXAttributeItem::Attribute(attr) = item {
+ attr.0.value.as_ref()
+ } else {
+ None
+ }
+}
+
+fn is_valid_lang_prop(item: &JSXAttributeItem) -> bool {
+ match get_prop_value(item) {
+ Some(JSXAttributeValue::ExpressionContainer(JSXExpressionContainer {
+ expression: JSXExpression::Expression(expr),
+ ..
+ })) => !expr.is_undefined(),
+ Some(JSXAttributeValue::StringLiteral(str)) => {
+ let language_tag = LanguageTag::parse(str.value.as_str()).unwrap();
+ language_tag.is_valid()
+ }
+ _ => true,
+ }
+}
+
+#[test]
+fn test() {
+ use crate::tester::Tester;
+
+ fn settings() -> serde_json::Value {
+ serde_json::json!({
+ "jsx-a11y": {
+ "polymorphicPropName": "as",
+ "components": {
+ "Foo": "html",
+ }
+ }
+ })
+ }
+
+ let pass = vec![
+ (";", None, None),
+ (";", None, None),
+ (";", None, None),
+ (" ", None, None),
+ ("