diff --git a/src/cli.ts b/src/cli.ts
index 8a62e03..5956597 100644
--- a/src/cli.ts
+++ b/src/cli.ts
@@ -48,6 +48,7 @@ program
   .option("--no-color", "Disable colored output")
   .option("--output-format <format>", "Output format: text (default) or json", "text")
   .option("--verbose", "Show detailed output from each agent")
+  .option("--whitespace-insensitive", "Ignore whitespace differences in convergence comparison")
   .option("--retry", "Re-run only failed/timed-out agents from the last run")
   .action(async (promptArg: string | undefined, opts) => {
     const testTimeout = parseInt(opts.testTimeout, 10);
@@ -100,6 +101,7 @@ program
         verbose: opts.verbose ?? false,
         outputFormat: opts.outputFormat,
         retry: true,
+        whitespaceInsensitive: opts.whitespaceInsensitive ?? false,
       });
       return;
     }
@@ -131,6 +133,7 @@ program
       scoring: opts.scoring,
       verbose: opts.verbose ?? false,
       outputFormat: opts.outputFormat,
+      whitespaceInsensitive: opts.whitespaceInsensitive ?? false,
     });
   });
 
diff --git a/src/commands/run.ts b/src/commands/run.ts
index 88e0ca2..7bfcade 100644
--- a/src/commands/run.ts
+++ b/src/commands/run.ts
@@ -202,7 +202,7 @@ export async function retry(opts: RunOptions): Promise<void> {
   }
 
   // Phase 5: Convergence analysis on full merged set
-  const convergence = analyzeConvergence(mergedAgents, opts.threshold);
+  const convergence = analyzeConvergence(mergedAgents, opts.threshold, opts.whitespaceInsensitive);
 
   // Phase 6: Recommendation
   const { recommended: weightedRec, scores } = recommend(mergedAgents, testResults, convergence);
@@ -346,7 +346,7 @@ export async function run(opts: RunOptions): Promise<void> {
   }
 
   // Phase 4: Convergence analysis
-  const convergence = analyzeConvergence(agents, opts.threshold);
+  const convergence = analyzeConvergence(agents, opts.threshold, opts.whitespaceInsensitive);
 
   // Phase 5: Recommendation
   const { recommended: weightedRec, scores } = recommend(agents, testResults, convergence);
diff --git a/src/scoring/convergence.ts b/src/scoring/convergence.ts
index e7cdae9..e0c172e 100644
--- a/src/scoring/convergence.ts
+++ b/src/scoring/convergence.ts
@@ -9,13 +9,20 @@ import { pairwiseSimilarity } from "./diff-parser.js";
  * Agents are clustered by diff similarity using single-linkage clustering
  * with a 0.5 similarity threshold.
  */
-export function analyzeConvergence(agents: AgentResult[], threshold = 0.3): ConvergenceGroup[] {
+export function analyzeConvergence(
+  agents: AgentResult[],
+  threshold = 0.3,
+  whitespaceInsensitive = false,
+): ConvergenceGroup[] {
   const completed = agents.filter((a) => a.status === "success" && a.diff.length > 0);
 
   if (completed.length === 0) return [];
 
   // Compute pairwise diff similarity
-  const similarities = pairwiseSimilarity(completed.map((a) => ({ id: a.id, diff: a.diff })));
+  const similarities = pairwiseSimilarity(
+    completed.map((a) => ({ id: a.id, diff: a.diff })),
+    whitespaceInsensitive,
+  );
 
   // Single-linkage clustering: merge agents with similarity >= threshold
   const clusters = clusterAgents(
diff --git a/src/scoring/diff-parser.test.ts b/src/scoring/diff-parser.test.ts
index d6028c1..7caa0ba 100644
--- a/src/scoring/diff-parser.test.ts
+++ b/src/scoring/diff-parser.test.ts
@@ -121,6 +121,65 @@ describe("diffSimilarity", () => {
   it("returns 1 for two empty diffs", () => {
     assert.equal(diffSimilarity("", ""), 1);
   });
+
+  it("treats reformatted code as different by default", () => {
+    const diffA = `diff --git a/a.ts b/a.ts
+--- a/a.ts
++++ b/a.ts
+@@ -1 +1 @@
++if (x) {  return  true; }`;
+    const diffB = `diff --git a/a.ts b/a.ts
+--- a/a.ts
++++ b/a.ts
+@@ -1 +1 @@
++if (x) { return true; }`;
+    const sim = diffSimilarity(diffA, diffB);
+    assert.ok(sim < 1, "default mode should see whitespace differences");
+  });
+
+  it("whitespace-insensitive mode treats reformatted code as identical", () => {
+    const diffA = `diff --git a/a.ts b/a.ts
+--- a/a.ts
++++ b/a.ts
+@@ -1 +1 @@
++if (x) {  return  true; }`;
+    const diffB = `diff --git a/a.ts b/a.ts
+--- a/a.ts
++++ b/a.ts
+@@ -1 +1 @@
++if (x) { return true; }`;
+    assert.equal(diffSimilarity(diffA, diffB, true), 1);
+  });
+
+  it("whitespace-insensitive mode normalizes indentation differences", () => {
+    const diffA = `diff --git a/a.ts b/a.ts
+--- a/a.ts
++++ b/a.ts
+@@ -1 +1 @@
++    const x = 1;
++        const y = 2;`;
+    const diffB = `diff --git a/a.ts b/a.ts
+--- a/a.ts
++++ b/a.ts
+@@ -1 +1 @@
++  const x = 1;
++  const y = 2;`;
+    assert.equal(diffSimilarity(diffA, diffB, true), 1);
+  });
+
+  it("whitespace-insensitive mode still detects real code differences", () => {
+    const diffA = `diff --git a/a.ts b/a.ts
+--- a/a.ts
++++ b/a.ts
+@@ -1 +1 @@
++const x = 1;`;
+    const diffB = `diff --git a/a.ts b/a.ts
+--- a/a.ts
++++ b/a.ts
+@@ -1 +1 @@
++const y = 2;`;
+    assert.equal(diffSimilarity(diffA, diffB, true), 0);
+  });
 });
 
 describe("pairwiseSimilarity", () => {
diff --git a/src/scoring/diff-parser.ts b/src/scoring/diff-parser.ts
index 7fd83ea..2fb0d94 100644
--- a/src/scoring/diff-parser.ts
+++ b/src/scoring/diff-parser.ts
@@ -54,11 +54,23 @@ export function parseDiff(diff: string): DiffFile[] {
   return files;
 }
 
+function normalizeLine(line: string, whitespaceInsensitive: boolean): string {
+  const trimmed = line.trim();
+  return whitespaceInsensitive ? trimmed.replace(/\s+/g, " ") : trimmed;
+}
+
 /**
  * Compute similarity between two diffs using Jaccard similarity
  * on the set of added lines. Returns 0-1 where 1 = identical changes.
+ *
+ * When whitespaceInsensitive is true, interior whitespace is collapsed
+ * before comparison so formatting-only differences don't lower scores.
  */
-export function diffSimilarity(diffA: string, diffB: string): number {
+export function diffSimilarity(
+  diffA: string,
+  diffB: string,
+  whitespaceInsensitive = false,
+): number {
   const filesA = parseDiff(diffA);
   const filesB = parseDiff(diffB);
 
@@ -68,12 +80,12 @@ export function diffSimilarity(diffA: string, diffB: string): number {
 
   for (const f of filesA) {
     for (const line of f.addedLines) {
-      setA.add(`${f.path}:${line.trim()}`);
+      setA.add(`${f.path}:${normalizeLine(line, whitespaceInsensitive)}`);
     }
   }
   for (const f of filesB) {
     for (const line of f.addedLines) {
-      setB.add(`${f.path}:${line.trim()}`);
+      setB.add(`${f.path}:${normalizeLine(line, whitespaceInsensitive)}`);
     }
   }
 
@@ -95,6 +107,7 @@ export function diffSimilarity(diffA: string, diffB: string): number {
  */
 export function pairwiseSimilarity(
   agents: Array<{ id: number; diff: string }>,
+  whitespaceInsensitive = false,
 ): Map<string, number> {
   const matrix = new Map<string, number>();
 
@@ -102,7 +115,7 @@ export function pairwiseSimilarity(
     for (let j = i + 1; j < agents.length; j++) {
       const a = agents[i]!;
       const b = agents[j]!;
-      const sim = diffSimilarity(a.diff, b.diff);
+      const sim = diffSimilarity(a.diff, b.diff, whitespaceInsensitive);
       matrix.set(`${a.id}-${b.id}`, sim);
     }
   }
diff --git a/src/types.ts b/src/types.ts
index a9c2f6b..ceae3ae 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -11,6 +11,7 @@ export interface RunOptions {
   scoring: "weighted" | "copeland";
   outputFormat: "text" | "json";
   retry?: boolean;
+  whitespaceInsensitive?: boolean;
 }
 
 export interface AgentResult {