diff --git a/crates/oxc/src/napi/transform.rs b/crates/oxc/src/napi/transform.rs
index d37ae5db6588ac..3d761b2ccee3b4 100644
--- a/crates/oxc/src/napi/transform.rs
+++ b/crates/oxc/src/napi/transform.rs
@@ -89,9 +89,11 @@ pub struct TransformOptions {
     pub inject: Option<FxHashMap<String, Either<String, Vec<String>>>>,
 }
 
-impl From<TransformOptions> for oxc_transformer::TransformOptions {
-    fn from(options: TransformOptions) -> Self {
-        Self {
+impl TryFrom<TransformOptions> for oxc_transformer::TransformOptions {
+    type Error = String;
+
+    fn try_from(options: TransformOptions) -> Result<Self, Self::Error> {
+        Ok(Self {
             cwd: options.cwd.map(PathBuf::from).unwrap_or_default(),
             typescript: options
                 .typescript
@@ -99,7 +101,7 @@ impl From<TransformOptions> for oxc_transformer::TransformOptions {
                 .unwrap_or_default(),
             jsx: options.jsx.map(Into::into).unwrap_or_default(),
             ..Self::default()
-        }
+        })
     }
 }
 
diff --git a/crates/oxc_transformer/src/options/babel/env/targets.rs b/crates/oxc_transformer/src/options/babel/env/targets.rs
index 554074dbee3893..b044f627f9d8ff 100644
--- a/crates/oxc_transformer/src/options/babel/env/targets.rs
+++ b/crates/oxc_transformer/src/options/babel/env/targets.rs
@@ -3,8 +3,6 @@ use std::str::FromStr;
 use rustc_hash::FxHashMap;
 use serde::Deserialize;
 
-use oxc_diagnostics::Error;
-
 pub use browserslist::Version;
 
 use crate::options::{BrowserslistQuery, Engine, EngineTargets};
@@ -35,7 +33,7 @@ pub enum BabelTargetsValue {
 }
 
 impl TryFrom<BabelTargets> for EngineTargets {
-    type Error = Error;
+    type Error = String;
     fn try_from(value: BabelTargets) -> Result<Self, Self::Error> {
         match value {
             BabelTargets::String(s) => BrowserslistQuery::Single(s).exec(),
@@ -52,7 +50,7 @@ impl TryFrom<BabelTargets> for EngineTargets {
                         continue;
                     };
                     let BabelTargetsValue::String(v) = value else {
-                        return Err(Error::msg(format!("{value:?} is not a string for {key}.")));
+                        return Err(format!("{value:?} is not a string for {key}."));
                     };
                     // TODO: Implement this target.
                     if key == "node" && v == "current" {
@@ -66,16 +64,14 @@ impl TryFrom<BabelTargets> for EngineTargets {
                     // <https://babel.dev/docs/options#targets>:
                     // Supported environments: android, chrome, deno, edge, electron, firefox, ie, ios, node, opera, rhino, safari, samsung.
                     let Ok(engine) = Engine::from_str(&key) else {
-                        return Err(Error::msg(format!("engine '{key}' is not supported.")));
+                        return Err(format!("engine '{key}' is not supported."));
                     };
                     match Version::parse(&v) {
                         Ok(version) => {
                             engine_targets.insert(engine, version);
                         }
                         Err(err) => {
-                            return Err(oxc_diagnostics::Error::msg(format!(
-                                "Failed to parse `{v}` for `{key}`\n{err:?}"
-                            )))
+                            return Err(format!("Failed to parse `{v}` for `{key}`\n{err:?}"))
                         }
                     }
                 }
diff --git a/crates/oxc_transformer/src/options/browserslist_query.rs b/crates/oxc_transformer/src/options/browserslist_query.rs
index da02331912eb28..84acb91de264cf 100644
--- a/crates/oxc_transformer/src/options/browserslist_query.rs
+++ b/crates/oxc_transformer/src/options/browserslist_query.rs
@@ -3,8 +3,6 @@ use std::sync::OnceLock;
 use dashmap::DashMap;
 use serde::Deserialize;
 
-use oxc_diagnostics::{Error, OxcDiagnostic};
-
 use super::EngineTargets;
 
 #[derive(Debug, Clone, Deserialize, Eq, PartialEq, PartialOrd, Ord, Hash)]
@@ -20,7 +18,7 @@ fn cache() -> &'static DashMap<BrowserslistQuery, EngineTargets> {
 }
 
 impl BrowserslistQuery {
-    pub fn exec(&self) -> Result<EngineTargets, Error> {
+    pub fn exec(&self) -> Result<EngineTargets, String> {
         if let Some(v) = cache().get(self) {
             return Ok(v.clone());
         }
@@ -50,9 +48,7 @@ impl BrowserslistQuery {
                     .collect::<Vec<_>>();
                 EngineTargets::parse_versions(versions)
             }
-            Err(err) => {
-                return Err(OxcDiagnostic::error(format!("failed to resolve query: {err}")).into())
-            }
+            Err(err) => return Err(format!("failed to resolve query: {err}")),
         };
 
         cache().insert(self.clone(), result.clone());
diff --git a/crates/oxc_transformer/src/options/engine.rs b/crates/oxc_transformer/src/options/engine.rs
index d3217970faa570..699f84ac184d42 100644
--- a/crates/oxc_transformer/src/options/engine.rs
+++ b/crates/oxc_transformer/src/options/engine.rs
@@ -2,7 +2,6 @@ use std::{str::FromStr, sync::OnceLock};
 
 use browserslist::Version;
 use cow_utils::CowUtils;
-use oxc_diagnostics::Error;
 use rustc_hash::FxHashMap;
 use serde::Deserialize;
 
@@ -38,17 +37,17 @@ impl Engine {
     ///
     /// * No matching target
     /// * Invalid version
-    pub fn parse_name_and_version(s: &str) -> Result<(Engine, Version), Error> {
+    pub fn parse_name_and_version(s: &str) -> Result<(Engine, Version), String> {
         let s = s.cow_to_ascii_lowercase();
         for (name, engine) in engines() {
             if let Some(v) = s.strip_prefix(name) {
                 return Version::from_str(v).map(|version| (*engine,version))
-                    .map_err(|_| Error::msg(
-                        r#"All version numbers must be in the format "X", "X.Y", or "X.Y.Z" where X, Y, and Z are non-negative integers."#,
-                    ));
+                    .map_err(|_|
+                        String::from(r#"All version numbers must be in the format "X", "X.Y", or "X.Y.Z" where X, Y, and Z are non-negative integers."#),
+                    );
             }
         }
-        Err(Error::msg(format!("Invalid target '{s}'.")))
+        Err(format!("Invalid target '{s}'."))
     }
 }
 
diff --git a/crates/oxc_transformer/src/options/engine_targets.rs b/crates/oxc_transformer/src/options/engine_targets.rs
index ddbc9eaf0e4311..d5724b29655f89 100644
--- a/crates/oxc_transformer/src/options/engine_targets.rs
+++ b/crates/oxc_transformer/src/options/engine_targets.rs
@@ -8,8 +8,6 @@ use browserslist::Version;
 use rustc_hash::FxHashMap;
 use serde::Deserialize;
 
-use oxc_diagnostics::Error;
-
 use super::{
     babel::BabelTargets,
     engine::Engine,
@@ -42,7 +40,7 @@ impl EngineTargets {
     /// # Errors
     ///
     /// * Query is invalid.
-    pub fn try_from_query(query: &str) -> Result<Self, Error> {
+    pub fn try_from_query(query: &str) -> Result<Self, String> {
         BrowserslistQuery::Single(query.to_string()).exec()
     }
 
diff --git a/crates/oxc_transformer/src/options/env.rs b/crates/oxc_transformer/src/options/env.rs
index a148068ae8571a..8d1011897894ae 100644
--- a/crates/oxc_transformer/src/options/env.rs
+++ b/crates/oxc_transformer/src/options/env.rs
@@ -1,6 +1,5 @@
 use std::str::FromStr;
 
-use oxc_diagnostics::Error;
 use serde::Deserialize;
 
 use crate::{
@@ -101,11 +100,14 @@ impl EnvOptions {
     /// * When the query failed to parse.
     ///
     /// [browserslist]: <https://github.com/browserslist/browserslist>
-    pub fn from_browserslist_query(query: &str) -> Result<Self, Error> {
+    pub fn from_browserslist_query(query: &str) -> Result<Self, String> {
         EngineTargets::try_from_query(query).map(Self::from)
     }
 
-    pub(crate) fn from_target(s: &str) -> Result<Self, Error> {
+    /// # Errors
+    ///
+    /// * When the query failed to parse.
+    pub fn from_target(s: &str) -> Result<Self, String> {
         if s.contains(',') {
             Self::from_target_list(&s.split(',').collect::<Vec<_>>())
         } else {
@@ -113,7 +115,10 @@ impl EnvOptions {
         }
     }
 
-    pub(crate) fn from_target_list<S: AsRef<str>>(list: &[S]) -> Result<Self, Error> {
+    /// # Errors
+    ///
+    /// * When the query failed to parse.
+    pub fn from_target_list<S: AsRef<str>>(list: &[S]) -> Result<Self, String> {
         let mut es_target = None;
         let mut engine_targets = EngineTargets::default();
 
@@ -122,14 +127,14 @@ impl EnvOptions {
             // Parse `esXXXX`.
             if let Ok(target) = ESTarget::from_str(s) {
                 if let Some(target) = es_target {
-                    return Err(Error::msg(format!("'{target}' is already specified.")));
+                    return Err(format!("'{target}' is already specified."));
                 }
                 es_target = Some(target);
             } else {
                 // Parse `chromeXX`, `edgeXX` etc.
                 let (engine, version) = Engine::parse_name_and_version(s)?;
                 if engine_targets.insert(engine, version).is_some() {
-                    return Err(Error::msg(format!("'{s}' is already specified.")));
+                    return Err(format!("'{s}' is already specified."));
                 }
             }
         }
diff --git a/crates/oxc_transformer/src/options/mod.rs b/crates/oxc_transformer/src/options/mod.rs
index 04085fb6eb9d65..076fcdb4f441d2 100644
--- a/crates/oxc_transformer/src/options/mod.rs
+++ b/crates/oxc_transformer/src/options/mod.rs
@@ -10,8 +10,6 @@ mod module;
 
 use std::path::PathBuf;
 
-use oxc_diagnostics::Error;
-
 use crate::{
     common::helper_loader::{HelperLoaderMode, HelperLoaderOptions},
     compiler_assumptions::CompilerAssumptions,
@@ -97,7 +95,7 @@ impl TransformOptions {
     /// * Same targets specified multiple times.
     /// * No matching target.
     /// * Invalid version.
-    pub fn from_target(s: &str) -> Result<Self, Error> {
+    pub fn from_target(s: &str) -> Result<Self, String> {
         EnvOptions::from_target(s).map(|env| Self { env, ..Self::default() })
     }
 
@@ -115,7 +113,7 @@ impl TransformOptions {
     /// * Same targets specified multiple times.
     /// * No matching target.
     /// * Invalid version.
-    pub fn from_target_list<S: AsRef<str>>(list: &[S]) -> Result<Self, Error> {
+    pub fn from_target_list<S: AsRef<str>>(list: &[S]) -> Result<Self, String> {
         EnvOptions::from_target_list(list).map(|env| Self { env, ..Self::default() })
     }
 }
@@ -129,13 +127,13 @@ impl From<ESTarget> for TransformOptions {
 }
 
 impl TryFrom<&BabelOptions> for TransformOptions {
-    type Error = Vec<Error>;
+    type Error = Vec<String>;
 
     /// If the `options` contains any unknown fields, they will be returned as a list of errors.
     fn try_from(options: &BabelOptions) -> Result<Self, Self::Error> {
-        let mut errors = Vec::<Error>::new();
-        errors.extend(options.plugins.errors.iter().map(|err| Error::msg(err.clone())));
-        errors.extend(options.presets.errors.iter().map(|err| Error::msg(err.clone())));
+        let mut errors = Vec::<String>::new();
+        errors.extend(options.plugins.errors.iter().map(Clone::clone));
+        errors.extend(options.presets.errors.iter().map(Clone::clone));
 
         let typescript = options
             .presets
diff --git a/napi/transform/index.d.ts b/napi/transform/index.d.ts
index 9fd1aca75d5cbc..ba8aeec642a2fb 100644
--- a/napi/transform/index.d.ts
+++ b/napi/transform/index.d.ts
@@ -203,6 +203,7 @@ export interface TransformOptions {
   typescript?: TypeScriptOptions
   /** Configure how TSX and JSX are transformed. */
   jsx?: JsxOptions
+  target?: string | Array<string>
   /** Define Plugin */
   define?: Record<string, string>
   /** Inject Plugin */
diff --git a/napi/transform/src/transformer.rs b/napi/transform/src/transformer.rs
index 0e5dca677e12ee..29886efb6dbeb5 100644
--- a/napi/transform/src/transformer.rs
+++ b/napi/transform/src/transformer.rs
@@ -84,8 +84,11 @@ impl Compiler {
             .transpose()?
             .map(InjectGlobalVariablesConfig::new);
 
-        let transform_options =
-            options.map(oxc::transformer::TransformOptions::from).unwrap_or_default();
+        let transform_options = match options {
+            Some(options) => oxc::transformer::TransformOptions::try_from(options)
+                .map_err(|err| vec![OxcDiagnostic::error(err)])?,
+            None => oxc::transformer::TransformOptions::default(),
+        };
 
         Ok(Self {
             transform_options,
diff --git a/tasks/transform_conformance/src/test_case.rs b/tasks/transform_conformance/src/test_case.rs
index 88758d2eedd992..f34a48f8d189b7 100644
--- a/tasks/transform_conformance/src/test_case.rs
+++ b/tasks/transform_conformance/src/test_case.rs
@@ -8,7 +8,7 @@ use oxc::parser::ParseOptions;
 use oxc::{
     allocator::Allocator,
     codegen::{CodeGenerator, CodegenOptions},
-    diagnostics::{Error, NamedSource, OxcDiagnostic},
+    diagnostics::{NamedSource, OxcDiagnostic},
     parser::Parser,
     span::{SourceType, VALID_EXTENSIONS},
     transformer::{BabelOptions, HelperLoaderMode, TransformOptions},
@@ -27,7 +27,7 @@ pub struct TestCase {
     pub path: PathBuf,
     options: BabelOptions,
     source_type: SourceType,
-    transform_options: Result<TransformOptions, Vec<Error>>,
+    transform_options: Result<TransformOptions, Vec<String>>,
     pub errors: Vec<OxcDiagnostic>,
 }