diff --git a/angular.json b/angular.json
index 9644e41..8fe5af1 100644
--- a/angular.json
+++ b/angular.json
@@ -20,7 +20,14 @@
             "browser": "src/main.ts",
             "polyfills": [],
             "tsConfig": "tsconfig.app.json",
-            "assets": ["src/assets"],
+            "assets": [
+              "src/assets",
+              {
+                "glob": "**/*",
+                "input": "node_modules/monaco-editor",
+                "output": "/assets/monaco/"
+              }
+            ],
             "styles": [
               "src/styles.scss",
               "highlight.js/styles/atom-one-dark.min.css"
diff --git a/bun.lockb b/bun.lockb
index 9546164..2ff8378 100755
Binary files a/bun.lockb and b/bun.lockb differ
diff --git a/package.json b/package.json
index c9995b0..c17eb63 100644
--- a/package.json
+++ b/package.json
@@ -24,6 +24,8 @@
     "@angular/router": "^18.1.0",
     "@tauri-apps/api": "^1.6.0",
     "highlight.js": "^11.10.0",
+    "monaco-editor": "^0.50.0",
+    "ngx-monaco-editor-v2": "^18.0.1",
     "protobufjs": "^7.3.2",
     "rxjs": "^7.8.1",
     "tslib": "^2.6.3",
diff --git a/src/app/app.component.scss b/src/app/app.component.scss
index 2fa6f54..63431fe 100644
--- a/src/app/app.component.scss
+++ b/src/app/app.component.scss
@@ -22,6 +22,7 @@ mat-sidenav-content {
 
 app-editor {
   flex: 1;
+  width: 100%;
 }
 
 .mat-sidenav.mat-drawer-end,
diff --git a/src/app/app.component.ts b/src/app/app.component.ts
index e69a5de..828cbe6 100644
--- a/src/app/app.component.ts
+++ b/src/app/app.component.ts
@@ -1,6 +1,6 @@
 import { BreakpointObserver, Breakpoints } from '@angular/cdk/layout';
 import { CommonModule } from '@angular/common';
-import { Component, computed, signal } from '@angular/core';
+import { Component, computed, effect, signal } from '@angular/core';
 import { takeUntilDestroyed } from '@angular/core/rxjs-interop';
 import { MatButtonModule } from '@angular/material/button';
 import { MatIconModule } from '@angular/material/icon';
diff --git a/src/app/app.config.ts b/src/app/app.config.ts
index 7262144..08229d7 100644
--- a/src/app/app.config.ts
+++ b/src/app/app.config.ts
@@ -13,6 +13,7 @@ import {
   MAT_ICON_DEFAULT_OPTIONS,
   MatIconRegistry,
 } from '@angular/material/icon';
+import { provideMonacoEditor } from 'ngx-monaco-editor-v2';
 
 export const appConfig: ApplicationConfig = {
   providers: [
@@ -41,5 +42,6 @@ export const appConfig: ApplicationConfig = {
       provide: MAT_ICON_DEFAULT_OPTIONS,
       useValue: { fontSet: 'material-symbols-rounded' },
     },
+    provideMonacoEditor(),
   ],
 };
diff --git a/src/app/editor/editor.component.html b/src/app/editor/editor.component.html
index a8772d5..5e58df2 100644
--- a/src/app/editor/editor.component.html
+++ b/src/app/editor/editor.component.html
@@ -14,13 +14,36 @@
   ></app-proto-field>
   } }
 </div>
-
 @if(showRaw()) {
-<h2>Preview</h2>
-<div class="actions">
-  <button mat-flat-button (click)="copyToClipboard()">Copy</button>
-</div>
-<pre><code #code></code></pre>
-}
+<div class="preview">
+  <h2>
+    Preview
+    <mat-button-toggle-group [(value)]="previewType">
+      <mat-button-toggle value="raw">Raw</mat-button-toggle>
+      <mat-button-toggle value="edit">Edit</mat-button-toggle>
+      @if(selectedFile()) {
+      <mat-button-toggle value="diff">Diff</mat-button-toggle>
+      }
+    </mat-button-toggle-group>
+    <button mat-flat-button (click)="copyToClipboard()">Copy</button>
+  </h2>
 
+  @switch (previewType()) { @case ('raw') {
+  <pre><code #code></code></pre>
+  } @case ('edit') {
+  <ngx-monaco-editor
+    #monaco
+    [options]="editorOptions"
+    [ngModel]="serialisedValues()"
+    (ngModelChange)="updateValuesFromText($event)"
+  ></ngx-monaco-editor>
+  } @case ('diff') {
+  <ngx-monaco-diff-editor
+    [options]="editorOptions"
+    [originalModel]="originalModel()"
+    [modifiedModel]="currentModel()"
+  ></ngx-monaco-diff-editor>
+  } }
+</div>
+}
 <a #downloader [href]="saveHref()" [download]="downloadName()"></a>
diff --git a/src/app/editor/editor.component.scss b/src/app/editor/editor.component.scss
index e708522..e386a09 100644
--- a/src/app/editor/editor.component.scss
+++ b/src/app/editor/editor.component.scss
@@ -2,10 +2,11 @@
   padding: var(--mat-sidenav-container-shape);
   display: flex;
   flex-direction: column;
+  box-sizing: border-box;
 }
 
-pre,
-.editor-items {
+.editor-items,
+.preview {
   flex: 1;
   overflow: auto;
 }
@@ -14,11 +15,16 @@ pre,
   padding: 16px;
 }
 
-.actions {
-  flex: 0 0 auto;
-}
-
 .proto-title {
   display: flex;
   justify-content: space-between;
 }
+
+mat-button-toggle-group {
+  width: fit-content;
+}
+
+ngx-monaco-editor,
+ngx-monaco-diff-editor {
+  height: 100%;
+}
diff --git a/src/app/editor/editor.component.ts b/src/app/editor/editor.component.ts
index a44cc77..aea79c5 100644
--- a/src/app/editor/editor.component.ts
+++ b/src/app/editor/editor.component.ts
@@ -18,13 +18,26 @@ import hljs from 'highlight.js/lib/core';
 import { ProtoMessage } from '../model/proto-message.model';
 import { ProtoFieldComponent } from './proto-field/proto-field.component';
 import { save } from '@tauri-apps/api/dialog';
+import { MatButtonToggleModule } from '@angular/material/button-toggle';
+import { MonacoEditorModule } from 'ngx-monaco-editor-v2';
+import { FormsModule } from '@angular/forms';
 
 declare const __TAURI__: any;
 
+type PreviewType = 'raw' | 'edit' | 'diff';
+
 @Component({
   selector: 'app-editor',
   standalone: true,
-  imports: [CommonModule, ProtoFieldComponent, MatButtonModule, MatIconModule],
+  imports: [
+    CommonModule,
+    ProtoFieldComponent,
+    MatButtonModule,
+    MatButtonToggleModule,
+    MatIconModule,
+    MonacoEditorModule,
+    FormsModule,
+  ],
   templateUrl: './editor.component.html',
   styleUrl: './editor.component.scss',
 })
@@ -34,11 +47,16 @@ export class EditorComponent {
   indentSize = input<number>(2);
   showRaw = input<boolean>(true);
 
+  protected editorOptions = {
+    theme: 'vs-dark',
+    language: 'json',
+    automaticLayout: true,
+  };
   protected values = signal<any>(undefined);
   protected downloadName = computed(
     () => this.selectedFile() ?? `${this.selectedMessage().name}.json`
   );
-  private serialisedValues = computed(() =>
+  protected serialisedValues = computed(() =>
     JSON.stringify(this.values(), undefined, this.indentSize())
   );
   protected saveHref = computed(() => {
@@ -48,6 +66,16 @@ export class EditorComponent {
     return URL.createObjectURL(blob);
   });
   protected downloader = viewChild<ElementRef<HTMLAnchorElement>>('downloader');
+  protected previewType = signal<PreviewType>('raw');
+  protected currentFileContents = signal<string>('');
+  protected originalModel = computed(() => ({
+    code: this.currentFileContents(),
+    language: 'json',
+  }));
+  protected currentModel = computed(() => ({
+    code: this.serialisedValues(),
+    language: 'json',
+  }));
 
   private code = viewChild<ElementRef<HTMLElement>>('code');
 
@@ -85,24 +113,23 @@ export class EditorComponent {
       const selectedFile = this.selectedFile();
       if (selectedFile) {
         const fileContents = await readTextFile(selectedFile);
-        try {
-          const parsed = JSON.parse(fileContents);
-          this.values.set(parsed);
-        } catch (err) {
-          console.error(
-            `Failed to parse contents of file ${selectedFile}`,
-            err
-          );
-          this.snackBar.open(
-            `Failed to parse contents of file ${selectedFile}, please check the file is correctly formatted`,
-            'Dismiss',
-            { duration: 5000 }
-          );
-        }
+        this.currentFileContents.set(fileContents);
+        this.updateValuesFromText(fileContents, selectedFile);
       }
     });
   }
 
+  protected updateValuesFromText(text: string, selectedFile?: string) {
+    try {
+      const parsed = JSON.parse(text);
+      this.values.set(parsed);
+    } catch (err) {
+      if (selectedFile) {
+        console.error(`Failed to parse contents of file ${selectedFile}`, err);
+      }
+    }
+  }
+
   protected updateValue(key: string, value: any) {
     const existingValue = { ...this.values() };
     existingValue[key] = value;
diff --git a/src/styles.scss b/src/styles.scss
index b730084..9878d19 100644
--- a/src/styles.scss
+++ b/src/styles.scss
@@ -30,6 +30,7 @@ html {
   @include mat.list-theme(theme.$rose-theme);
   @include mat.select-theme(theme.$rose-theme);
   @include mat.snack-bar-theme(theme.$rose-theme);
+  @include mat.button-toggle-theme(theme.$rose-theme);
   @include custom-colours(theme.$rose-theme);
 }