diff --git a/src/core/operations/Diff.mjs b/src/core/operations/Diff.mjs
index 9f180f86..dd05f45b 100644
--- a/src/core/operations/Diff.mjs
+++ b/src/core/operations/Diff.mjs
@@ -57,6 +57,12 @@ class Diff extends Operation {
                 "type": "boolean",
                 "value": false,
                 "hint": "Relevant for word and line"
+            },
+            {
+                "name": "Show +/- notation",
+                "hint": "Works only in Line diff mode.",
+                "type": "boolean",
+                "value": false
             }
         ];
     }
@@ -73,7 +79,8 @@ class Diff extends Operation {
                 showAdded,
                 showRemoved,
                 showSubtraction,
-                ignoreWhitespace
+                ignoreWhitespace,
+                showNotation
             ] = args,
             samples = input.split(sampleDelim);
         let output = "",
@@ -86,6 +93,34 @@ class Diff extends Operation {
             throw new OperationError("Incorrect number of samples, perhaps you need to modify the sample delimiter or add more samples?");
         }
 
+        // +/- notation only works properly with Line diff mode
+        // For other modes, it falls back to HTML format and this option is ignored (see hint).
+        const useNotation = showNotation && diffBy === "Line";
+
+        if (useNotation) {
+            const patch = jsdiff.createTwoFilesPatch("original", "modified", samples[0], samples[1], "", "", {
+                context: Infinity,
+                ignoreWhitespace: ignoreWhitespace,
+            });
+
+            const lines = patch.split("\n");
+            for (let i = 0; i < lines.length; i++) {
+                const line = lines[i];
+                if (line.startsWith("@@")) {
+                    if (showSubtraction) output += line + "\n";
+                } else if (line.startsWith("+") && !line.startsWith("+++")) {
+                    if (showAdded) output += line + "\n";
+                } else if (line.startsWith("-") && !line.startsWith("---")) {
+                    if (showRemoved) output += line + "\n";
+                } else if (line.startsWith("===") || line.startsWith("---") || line.startsWith("+++") || line.startsWith("\\")) {
+                    continue;
+                } else if (line.length > 0 && !showSubtraction) {
+                    output += line.substring(1) + "\n";
+                }
+            }
+            return output.slice(0, -1);
+        }
+
         switch (diffBy) {
             case "Character":
                 diff = jsdiff.diffChars(samples[0], samples[1]);
diff --git a/tests/operations/tests/Diff.mjs b/tests/operations/tests/Diff.mjs
new file mode 100644
index 00000000..e2d08875
--- /dev/null
+++ b/tests/operations/tests/Diff.mjs
@@ -0,0 +1,313 @@
+/**
+ * @author mikecat
+ * @copyright Crown Copyright 2023
+ * @license Apache-2.0
+ */
+import TestRegister from "../../lib/TestRegister.mjs";
+
+TestRegister.addTests([
+    {
+        "name": "Diff: Show +/- notation - true (Line mode)",
+        "input": "line1\nline2\nline3\n\nline1\nline2modified\nline3",
+        "expectedOutput": "line1\n-line2\n+line2modified\nline3",
+        "recipeConfig": [
+            {
+                "op": "Diff",
+                "args": [
+                    "\\n\\n",
+                    "Line",
+                    true,
+                    true,
+                    false,
+                    false,
+                    true
+                ],
+            },
+        ],
+    },
+    {
+        "name": "Diff: Show +/- notation - false (Line mode)",
+        "input": "line1\nline2\nline3\n\nline1\nline2modified\nline3",
+        "expectedOutput": "line1\n<del>line2\n</del><ins>line2modified\n</ins>line3",
+        "recipeConfig": [
+            {
+                "op": "Diff",
+                "args": [
+                    "\\n\\n",
+                    "Line",
+                    true,
+                    true,
+                    false,
+                    false,
+                    false
+                ],
+            },
+        ],
+    },
+    {
+        "name": "Diff: Show +/- notation - with showAdded false (Line mode)",
+        "input": "line1\nline2\nline3\n\nline1\nline2modified\nline3",
+        "expectedOutput": "line1\n-line2\nline3",
+        "recipeConfig": [
+            {
+                "op": "Diff",
+                "args": [
+                    "\\n\\n",
+                    "Line",
+                    false,
+                    true,
+                    false,
+                    false,
+                    true
+                ],
+            },
+        ],
+    },
+    {
+        "name": "Diff: Show +/- notation - with showRemoved false (Line mode)",
+        "input": "line1\nline2\nline3\n\nline1\nline2modified\nline3",
+        "expectedOutput": "line1\n+line2modified\nline3",
+        "recipeConfig": [
+            {
+                "op": "Diff",
+                "args": [
+                    "\\n\\n",
+                    "Line",
+                    true,
+                    false,
+                    false,
+                    false,
+                    true
+                ],
+            },
+        ],
+    },
+    {
+        "name": "Diff: Show +/- notation - with showSubtraction true (Line mode)",
+        "input": "line1\nline2\nline3\n\nline1\nline2modified\nline3",
+        "expectedOutput": "@@ -1,3 +1,3 @@\n-line2\n+line2modified",
+        "recipeConfig": [
+            {
+                "op": "Diff",
+                "args": [
+                    "\\n\\n",
+                    "Line",
+                    true,
+                    true,
+                    true,
+                    false,
+                    true
+                ],
+            },
+        ],
+    },
+    {
+        "name": "Diff: Show +/- notation ignored for Character mode",
+        "input": "abc\ndef",
+        "expectedOutput": "<del>abc</del><ins>def</ins>",
+        "recipeConfig": [
+            {
+                "op": "Diff",
+                "args": [
+                    "\\n",
+                    "Character",
+                    true,
+                    true,
+                    false,
+                    false,
+                    true
+                ],
+            },
+        ],
+    },
+    {
+        "name": "Diff: Show +/- notation ignored for Word mode",
+        "input": "hello world\nhello cruel world",
+        "expectedOutput": "hello <ins>cruel </ins>world",
+        "recipeConfig": [
+            {
+                "op": "Diff",
+                "args": [
+                    "\\n",
+                    "Word",
+                    true,
+                    true,
+                    false,
+                    false,
+                    true
+                ],
+            },
+        ],
+    },
+    {
+        "name": "Diff: Show +/- notation ignored for Sentence mode",
+        "input": "Hello world.\nHello there.",
+        "expectedOutput": "<del>Hello world.</del><ins>Hello there.</ins>",
+        "recipeConfig": [
+            {
+                "op": "Diff",
+                "args": [
+                    "\\n",
+                    "Sentence",
+                    true,
+                    true,
+                    false,
+                    false,
+                    true
+                ],
+            },
+        ],
+    },
+    {
+        "name": "Diff: Character mode basic",
+        "input": "abc\nabc",
+        "expectedOutput": "abc",
+        "recipeConfig": [
+            {
+                "op": "Diff",
+                "args": [
+                    "\\n",
+                    "Character",
+                    true,
+                    true,
+                    false,
+                    false,
+                    false
+                ],
+            },
+        ],
+    },
+    {
+        "name": "Diff: Character mode with changes",
+        "input": "abc\nabcdef",
+        "expectedOutput": "abc<ins>def</ins>",
+        "recipeConfig": [
+            {
+                "op": "Diff",
+                "args": [
+                    "\\n",
+                    "Character",
+                    true,
+                    true,
+                    false,
+                    false,
+                    false
+                ],
+            },
+        ],
+    },
+    {
+        "name": "Diff: Word mode basic",
+        "input": "hello world\nhello world",
+        "expectedOutput": "hello world",
+        "recipeConfig": [
+            {
+                "op": "Diff",
+                "args": [
+                    "\\n",
+                    "Word",
+                    true,
+                    true,
+                    false,
+                    false,
+                    false
+                ],
+            },
+        ],
+    },
+    {
+        "name": "Diff: Word mode with changes",
+        "input": "hello world\nhello cruel world",
+        "expectedOutput": "hello <ins>cruel </ins>world",
+        "recipeConfig": [
+            {
+                "op": "Diff",
+                "args": [
+                    "\\n",
+                    "Word",
+                    true,
+                    true,
+                    false,
+                    false,
+                    false
+                ],
+            },
+        ],
+    },
+    {
+        "name": "Diff: Line mode basic",
+        "input": "line1\nline2\nline3\n\nline1\nline2\nline3",
+        "expectedOutput": "line1\nline2\nline3",
+        "recipeConfig": [
+            {
+                "op": "Diff",
+                "args": [
+                    "\\n\\n",
+                    "Line",
+                    true,
+                    true,
+                    false,
+                    false,
+                    false
+                ],
+            },
+        ],
+    },
+    {
+        "name": "Diff: Line mode with changes",
+        "input": "line1\nline2\nline3\n\nline1\nline4\nline3",
+        "expectedOutput": "line1\n<del>line2\n</del><ins>line4\n</ins>line3",
+        "recipeConfig": [
+            {
+                "op": "Diff",
+                "args": [
+                    "\\n\\n",
+                    "Line",
+                    true,
+                    true,
+                    false,
+                    false,
+                    false
+                ],
+            },
+        ],
+    },
+    {
+        "name": "Diff: Sentence mode basic",
+        "input": "Hello world.\nHello world.",
+        "expectedOutput": "Hello world.",
+        "recipeConfig": [
+            {
+                "op": "Diff",
+                "args": [
+                    "\\n",
+                    "Sentence",
+                    true,
+                    true,
+                    false,
+                    false,
+                    false
+                ],
+            },
+        ],
+    },
+    {
+        "name": "Diff: Sentence mode with changes",
+        "input": "Hello world.\nHello there.",
+        "expectedOutput": "<del>Hello world.</del><ins>Hello there.</ins>",
+        "recipeConfig": [
+            {
+                "op": "Diff",
+                "args": [
+                    "\\n",
+                    "Sentence",
+                    true,
+                    true,
+                    false,
+                    false,
+                    false
+                ],
+            },
+        ],
+    },
+]);