diff --git a/Cargo.lock b/Cargo.lock
index 8bdf2f54741e0..16ba468cef009 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2088,7 +2088,6 @@ dependencies = [
 name = "oxc_minifier"
 version = "0.82.2"
 dependencies = [
- "base64",
  "cow-utils",
  "insta",
  "javascript-globals",
@@ -2100,6 +2099,7 @@ dependencies = [
  "oxc_mangler",
  "oxc_parser",
  "oxc_semantic",
+ "oxc_sourcemap",
  "oxc_span",
  "oxc_syntax",
  "oxc_traverse",
@@ -2469,6 +2469,7 @@ dependencies = [
  "oxc_tasks_common",
  "oxc_transformer",
  "oxc_traverse",
+ "pico-args",
  "rustc-hash",
  "similar",
 ]
diff --git a/crates/oxc_codegen/src/gen.rs b/crates/oxc_codegen/src/gen.rs
index 4cba6b821bad7..8407445d47798 100644
--- a/crates/oxc_codegen/src/gen.rs
+++ b/crates/oxc_codegen/src/gen.rs
@@ -923,7 +923,6 @@ impl Gen for WithClause<'_> {
             p.print_soft_space();
         }
         p.print_ascii_byte(b'}');
-        p.add_source_mapping_end(self.span);
     }
 }
 
@@ -1474,7 +1473,6 @@ impl Gen for ArrayExpression<'_> {
             p.print_indent();
         }
         p.print_ascii_byte(b']');
-        p.add_source_mapping_end(self.span);
     }
 }
 
@@ -1517,7 +1515,6 @@ impl GenExpr for ObjectExpression<'_> {
                 p.print_soft_space();
             }
             p.print_ascii_byte(b'}');
-            p.add_source_mapping_end(self.span);
         });
     }
 }
@@ -1905,7 +1902,6 @@ impl Gen for ArrayAssignmentTarget<'_> {
             target.print(p, ctx);
         }
         p.print_ascii_byte(b']');
-        p.add_source_mapping_end(self.span);
     }
 }
 
@@ -1922,7 +1918,6 @@ impl Gen for ObjectAssignmentTarget<'_> {
             target.print(p, ctx);
         }
         p.print_ascii_byte(b'}');
-        p.add_source_mapping_end(self.span);
     }
 }
 
@@ -2789,7 +2784,6 @@ impl Gen for ObjectPattern<'_> {
             p.print_soft_space();
         }
         p.print_ascii_byte(b'}');
-        p.add_source_mapping_end(self.span);
     }
 }
 
@@ -2863,7 +2857,6 @@ impl Gen for ArrayPattern<'_> {
             rest.print(p, ctx);
         }
         p.print_ascii_byte(b']');
-        p.add_source_mapping_end(self.span);
     }
 }
 
diff --git a/crates/oxc_codegen/src/lib.rs b/crates/oxc_codegen/src/lib.rs
index c1ec1bc36f019..908eb801b2c2f 100644
--- a/crates/oxc_codegen/src/lib.rs
+++ b/crates/oxc_codegen/src/lib.rs
@@ -514,7 +514,6 @@ impl<'a> Codegen<'a> {
             self.dedent();
             self.print_indent();
         }
-        self.add_source_mapping_end(span);
         self.print_ascii_byte(b'}');
     }
 
@@ -525,10 +524,9 @@ impl<'a> Codegen<'a> {
         self.indent();
     }
 
-    fn print_block_end(&mut self, span: Span) {
+    fn print_block_end(&mut self, _span: Span) {
         self.dedent();
         self.print_indent();
-        self.add_source_mapping_end(span);
         self.print_ascii_byte(b'}');
     }
 
@@ -845,14 +843,6 @@ impl<'a> Codegen<'a> {
         }
     }
 
-    fn add_source_mapping_end(&mut self, span: Span) {
-        if let Some(sourcemap_builder) = self.sourcemap_builder.as_mut() {
-            if !span.is_empty() {
-                sourcemap_builder.add_source_mapping(self.code.as_bytes(), span.end, None);
-            }
-        }
-    }
-
     fn add_source_mapping_for_name(&mut self, span: Span, name: &str) {
         if let Some(sourcemap_builder) = self.sourcemap_builder.as_mut() {
             if !span.is_empty() {
diff --git a/crates/oxc_minifier/Cargo.toml b/crates/oxc_minifier/Cargo.toml
index 470ff2aefbe8e..485685f772de9 100644
--- a/crates/oxc_minifier/Cargo.toml
+++ b/crates/oxc_minifier/Cargo.toml
@@ -38,8 +38,8 @@ rustc-hash = { workspace = true }
 
 [dev-dependencies]
 oxc_parser = { workspace = true }
+oxc_sourcemap = { workspace = true }
 
-base64 = { workspace = true }
 insta = { workspace = true }
 javascript-globals = { workspace = true }
 pico-args = { workspace = true }
diff --git a/crates/oxc_minifier/examples/minifier.rs b/crates/oxc_minifier/examples/minifier.rs
index 0c437d0faec57..591cbd12811b7 100644
--- a/crates/oxc_minifier/examples/minifier.rs
+++ b/crates/oxc_minifier/examples/minifier.rs
@@ -20,7 +20,6 @@
 
 use std::path::{Path, PathBuf};
 
-use base64::{Engine, prelude::BASE64_STANDARD};
 use pico_args::Arguments;
 
 use oxc_allocator::Allocator;
@@ -28,6 +27,7 @@ use oxc_codegen::{Codegen, CodegenOptions, CodegenReturn, CommentOptions};
 use oxc_mangler::MangleOptions;
 use oxc_minifier::{CompressOptions, Minifier, MinifierOptions};
 use oxc_parser::Parser;
+use oxc_sourcemap::SourcemapVisualizer;
 use oxc_span::SourceType;
 
 // Instruction:
@@ -53,16 +53,10 @@ fn main() -> std::io::Result<()> {
     let printed = ret.code;
     println!("{printed}");
 
-    if let Some(source_map) = ret.map {
-        let result = source_map.to_json_string();
-        let hash = BASE64_STANDARD.encode(format!(
-            "{}\0{}{}\0{}",
-            printed.len(),
-            printed,
-            result.len(),
-            result
-        ));
-        println!("https://evanw.github.io/source-map-visualization/#{hash}");
+    if let Some(map) = ret.map {
+        let visualizer = SourcemapVisualizer::new(&printed, &map);
+        println!("{}", visualizer.get_url());
+        println!("{}", visualizer.get_text());
     }
 
     if twice {
diff --git a/crates/oxc_transformer_plugins/Cargo.toml b/crates/oxc_transformer_plugins/Cargo.toml
index 4e02f928b2c2a..279c942b185b4 100644
--- a/crates/oxc_transformer_plugins/Cargo.toml
+++ b/crates/oxc_transformer_plugins/Cargo.toml
@@ -38,10 +38,13 @@ rustc-hash = { workspace = true }
 
 [dev-dependencies]
 insta = { workspace = true }
+pico-args = { workspace = true }
+similar = { workspace = true }
+
 oxc_codegen = { workspace = true }
 oxc_minifier = { workspace = true }
 oxc_parser = { workspace = true }
+oxc_semantic = { workspace = true }
 oxc_sourcemap = { workspace = true }
 oxc_tasks_common = { workspace = true }
 oxc_transformer = { workspace = true }
-similar = { workspace = true }
diff --git a/crates/oxc_transformer_plugins/examples/define.rs b/crates/oxc_transformer_plugins/examples/define.rs
new file mode 100644
index 0000000000000..8052ac3a9927c
--- /dev/null
+++ b/crates/oxc_transformer_plugins/examples/define.rs
@@ -0,0 +1,87 @@
+#![expect(clippy::print_stdout)]
+//! # Define Plugin Example
+//!
+//! This example demonstrates how to use the Oxc code generator to convert an AST
+//! back into JavaScript code. It supports minification and idempotency testing.
+//!
+//! ## Usage
+//!
+//! Create a `test.js` file and run:
+//! ```bash
+//! cargo run -p oxc_transformer_plugins --example define -- [filename]
+//! ```
+
+use std::path::Path;
+
+use pico_args::Arguments;
+
+use oxc_allocator::Allocator;
+use oxc_ast::ast::Program;
+use oxc_codegen::{Codegen, CodegenOptions, CodegenReturn};
+use oxc_parser::{ParseOptions, Parser};
+use oxc_semantic::SemanticBuilder;
+use oxc_sourcemap::SourcemapVisualizer;
+use oxc_span::SourceType;
+use oxc_transformer_plugins::{ReplaceGlobalDefines, ReplaceGlobalDefinesConfig};
+
+fn main() -> std::io::Result<()> {
+    let mut args = Arguments::from_env();
+
+    let defines = [("process.env.NODE_ENV", "development")];
+
+    let sourcemap = args.contains("--sourcemap");
+
+    let name = args.free_from_str().unwrap_or_else(|_| "test.js".to_string());
+    let path = Path::new(&name);
+    let sourcemap = sourcemap.then_some(path);
+
+    let source_text = std::fs::read_to_string(path)?;
+    let source_type = SourceType::from_path(path).unwrap();
+    let allocator = Allocator::default();
+
+    let mut program = parse(&allocator, &source_text, source_type);
+    let scoping = SemanticBuilder::new().build(&program).semantic.into_scoping();
+    let config = ReplaceGlobalDefinesConfig::new(&defines).unwrap();
+    let _ = ReplaceGlobalDefines::new(&allocator, config).build(scoping, &mut program);
+    let printed = codegen(&program, sourcemap);
+
+    println!("{printed}");
+
+    Ok(())
+}
+
+/// Parse JavaScript/TypeScript source code into an AST
+fn parse<'a>(
+    allocator: &'a Allocator,
+    source_text: &'a str,
+    source_type: SourceType,
+) -> Program<'a> {
+    let ret = Parser::new(allocator, source_text, source_type)
+        .with_options(ParseOptions {
+            allow_return_outside_function: true,
+            ..ParseOptions::default()
+        })
+        .parse();
+    for error in ret.errors {
+        println!("{:?}", error.with_source_code(source_text.to_string()));
+    }
+    ret.program
+}
+
+/// Generate JavaScript code from an AST
+fn codegen(program: &Program<'_>, source_map_path: Option<&Path>) -> String {
+    let options = CodegenOptions {
+        source_map_path: source_map_path.map(Path::to_path_buf),
+        ..CodegenOptions::default()
+    };
+
+    let CodegenReturn { code, map, .. } = Codegen::new().with_options(options).build(program);
+
+    if let Some(map) = map {
+        let visualizer = SourcemapVisualizer::new(&code, &map);
+        println!("{}", visualizer.get_url());
+        println!("{}", visualizer.get_text());
+    }
+
+    code
+}
diff --git a/napi/minify/test/minify.test.ts b/napi/minify/test/minify.test.ts
index 033d3b0239c7b..a3814b5d224ac 100644
--- a/napi/minify/test/minify.test.ts
+++ b/napi/minify/test/minify.test.ts
@@ -8,22 +8,19 @@ describe('simple', () => {
 
   it('matches output', () => {
     const ret = minify('test.js', code, { sourcemap: true });
-    expect(ret).toStrictEqual({
-      'code': 'function foo(){var e;e(void 0)}foo();',
-      'map': {
-        'mappings': 'AACA,SAAS,KAAM,CAAE,IAAIA,EAAKA,EAAI,OAAY,CAAC',
-        'names': [
-          'bar',
-        ],
-        'sources': [
-          'test.js',
-        ],
-        'sourcesContent': [
-          code,
-        ],
-        'version': 3,
-      },
-      'errors': [],
+    expect(ret.code).toEqual('function foo(){var e;e(void 0)}foo();');
+    expect(ret.errors.length).toBe(0);
+    expect(ret.map).toMatchObject({
+      'names': [
+        'bar',
+      ],
+      'sources': [
+        'test.js',
+      ],
+      'sourcesContent': [
+        code,
+      ],
+      'version': 3,
     });
   });
 
diff --git a/napi/transform/test/id.test.ts b/napi/transform/test/id.test.ts
index daeb61e8e904e..8ac53a9a881c4 100644
--- a/napi/transform/test/id.test.ts
+++ b/napi/transform/test/id.test.ts
@@ -19,7 +19,7 @@ describe('isolated declaration', () => {
 
   it('matches output', () => {
     const ret = oxc.isolatedDeclaration('test.ts', code, { sourcemap: true });
-    expect(ret).toStrictEqual({
+    expect(ret).toMatchObject({
       code: '/**\n' +
         '* jsdoc 1\n' +
         '*/\n' +
@@ -31,7 +31,6 @@ describe('isolated declaration', () => {
         '}\n' +
         'export declare class B {}\n',
       map: {
-        mappings: ';;;AAIE,OAAO,cAAM,EAAE;;;;CAIb;AACD;AAED,OAAO,cAAM,EAAE,CAAE',
         names: [],
         sources: ['test.ts'],
         sourcesContent: [code],
diff --git a/napi/transform/test/transform.test.ts b/napi/transform/test/transform.test.ts
index 57c078db662af..afd87510598ca 100644
--- a/napi/transform/test/transform.test.ts
+++ b/napi/transform/test/transform.test.ts
@@ -8,12 +8,11 @@ describe('simple', () => {
 
   it('matches output', () => {
     const ret = transform('test.ts', code, { sourcemap: true });
-    expect(ret).toStrictEqual({
+    expect(ret).toMatchObject({
       code: 'export class A {}\n',
       errors: [],
       helpersUsed: {},
       map: {
-        mappings: 'AAAA,OAAO,MAAM,EAAK,CAAE',
         names: [],
         sources: ['test.ts'],
         sourcesContent: ['export class A<T> {}'],
@@ -37,8 +36,7 @@ describe('simple', () => {
       typescript: { declaration: {} },
       sourcemap: true,
     });
-    expect(ret.declarationMap).toStrictEqual({
-      mappings: 'AAAA,OAAO,cAAM,EAAE,GAAG,CAAE',
+    expect(ret.declarationMap).toMatchObject({
       names: [],
       sources: ['test.ts'],
       sourcesContent: ['export class A<T> {}'],