diff --git a/data_visualization/js/visualization.js b/data_visualization/js/visualization.js
new file mode 100644
index 0000000..65bb8c3
--- /dev/null
+++ b/data_visualization/js/visualization.js
@@ -0,0 +1,145 @@
+"use strict";
+
+/**
+ * Visualization module for replication analysis dashboard.
+ * Responsible for rendering charts and updating tables dynamically.
+ */
+
+/**
+ * @typedef {Object} RunComparison
+ * @property {string} run_id
+ * @property {Object} metrics
+ * @property {number[]} metrics.bandwidth
+ * @property {number[]} metrics.retry_tailp99
+ * @property {string[]} segments
+ */
+
+/**
+ * Render bandwidth chart based on provided run data.
+ * @param {RunComparison} data
+ */
+export function renderBandwidthChart(data) {
+  const container = document.getElementById('bandwidth-chart');
+  if (!container) return;
+
+  container.innerHTML = '';
+
+  const canvas = document.createElement('canvas');
+  canvas.setAttribute('aria-label', 'Bandwidth Chart');
+  canvas.setAttribute('role', 'img');
+  container.appendChild(canvas);
+
+  const ctx = canvas.getContext('2d');
+  const bandwidth = data.metrics?.bandwidth ?? [];
+  if (!bandwidth.length) {
+    ctx.font = '16px sans-serif';
+    ctx.fillText('No bandwidth data available', 10, 30);
+    return;
+  }
+
+  const spacing = canvas.width / bandwidth.length || 5;
+  const maxValue = Math.max(...bandwidth);
+  const scale = (canvas.height - 20) / maxValue;
+
+  ctx.strokeStyle = '#3366cc';
+  ctx.beginPath();
+  bandwidth.forEach((val, i) => {
+    const x = i * spacing + 10;
+    const y = canvas.height - val * scale - 10;
+    if (i === 0) ctx.moveTo(x, y);
+    else ctx.lineTo(x, y);
+  });
+  ctx.stroke();
+}
+
+/**
+ * Render retry_tailp99 chart as a trend visualization.
+ * @param {RunComparison} data
+ */
+export function renderRetryTailChart(data) {
+  const container = document.getElementById('retry-tailp99-chart');
+  if (!container) return;
+
+  container.innerHTML = '';
+
+  const canvas = document.createElement('canvas');
+  canvas.setAttribute('aria-label', 'Retry Tailp99 Trend');
+  canvas.setAttribute('role', 'img');
+  container.appendChild(canvas);
+
+  const ctx = canvas.getContext('2d');
+  const retries = data.metrics?.retry_tailp99 ?? [];
+  if (!retries.length) {
+    ctx.font = '16px sans-serif';
+    ctx.fillText('No retry_tailp99 data available', 10, 30);
+    return;
+  }
+
+  const spacing = canvas.width / retries.length || 5;
+  const maxValue = Math.max(...retries);
+  const scale = (canvas.height - 20) / maxValue;
+
+  ctx.strokeStyle = '#cc3333';
+  ctx.beginPath();
+  retries.forEach((val, i) => {
+    const x = i * spacing + 10;
+    const y = canvas.height - val * scale - 10;
+    if (i === 0) ctx.moveTo(x, y);
+    else ctx.lineTo(x, y);
+  });
+  ctx.stroke();
+}
+
+/**
+ * Update results table with latest run metrics.
+ * @param {RunComparison} data
+ */
+export function updateResultsTable(data) {
+  const table = document.getElementById('results-table');
+  if (!table) return;
+
+  table.innerHTML = '';
+
+  const headerRow = document.createElement('tr');
+  ['Segment', 'Bandwidth', 'Retry Tail p99'].forEach(h => {
+    const th = document.createElement('th');
+    th.textContent = h;
+    headerRow.appendChild(th);
+  });
+  table.appendChild(headerRow);
+
+  const {segments = [], metrics: {bandwidth = [], retry_tailp99 = []} = {}} = data;
+  const len = Math.max(segments.length, bandwidth.length, retry_tailp99.length);
+
+  for (let i = 0; i < len; i++) {
+    const row = document.createElement('tr');
+    const seg = document.createElement('td');
+    seg.textContent = segments[i] ?? '-';
+
+    const bw = document.createElement('td');
+    bw.textContent = bandwidth[i]?.toFixed(2) ?? '-';
+
+    const rt = document.createElement('td');
+    rt.textContent = retry_tailp99[i]?.toFixed(2) ?? '-';
+
+    row.appendChild(seg);
+    row.appendChild(bw);
+    row.appendChild(rt);
+    table.appendChild(row);
+  }
+}
+
+/**
+ * Ensure responsiveness on resize.
+ */
+window.addEventListener('resize', () => {
+  const dataAttr = document.body.dataset.runComparison;
+  if (!dataAttr) return;
+  try {
+    const data = JSON.parse(dataAttr);
+    renderBandwidthChart(data);
+    renderRetryTailChart(data);
+  } catch (err) {
+    console.error('Failed to re-render charts on resize:', err);
+  }
+});
\ No newline at end of file