diff --git a/README.md b/README.md
index 1155a81..8ee7a71 100644
--- a/README.md
+++ b/README.md
@@ -249,6 +249,8 @@ browser-cli extract images                   # all <img> tags (src + alt)
 browser-cli extract text                     # all visible text (innerText)
 browser-cli extract json "#data"             # parse JSON inside a CSS selector
 browser-cli extract html                     # full HTML of the active tab
+browser-cli extract markdown                 # main page content as Markdown
+browser-cli extract markdown --selector "article"   # specific DOM subtree as Markdown
 ```
 
 ### Sessions
diff --git a/browser_cli/__init__.py b/browser_cli/__init__.py
index af6b754..d085fee 100644
--- a/browser_cli/__init__.py
+++ b/browser_cli/__init__.py
@@ -247,6 +247,9 @@ class BrowserCLI:
     def extract_json(self, selector: str):
         return self._cmd("extract.json", {"selector": selector})
 
+    def extract_markdown(self, selector: str | None = None) -> str:
+        return self._cmd("extract.markdown", {"selector": selector}) or ""
+
     # ── Session ───────────────────────────────────────────────────────────
 
     def session_save(self, name: str) -> None:
diff --git a/browser_cli/commands/extract.py b/browser_cli/commands/extract.py
index 3c2c89f..34c12e8 100644
--- a/browser_cli/commands/extract.py
+++ b/browser_cli/commands/extract.py
@@ -73,3 +73,11 @@ def extract_html():
     """Print the full HTML of the active tab to stdout."""
     html = _handle("extract.html")
     click.echo(html or "")
+
+
+@extract_group.command("markdown")
+@click.option("--selector", help="Extract only the DOM subtree matching this CSS selector.")
+def extract_markdown(selector):
+    """Extract the page's main content as Markdown."""
+    markdown = _handle("extract.markdown", {"selector": selector})
+    click.echo(markdown or "", nl=not (markdown or "").endswith("\n"))
diff --git a/extension/background.js b/extension/background.js
index fd03615..da75f44 100644
--- a/extension/background.js
+++ b/extension/background.js
@@ -123,6 +123,7 @@ async function dispatch(command, args) {
     case "extract.images": return domOp("extractImages", args);
     case "extract.text":   return domOp("extractText",   args);
     case "extract.json":   return domOp("extractJson",   args);
+    case "extract.markdown": return domOp("extractMarkdown", args);
     case "extract.html":   return tabsHtml({});
 
     // ── Session ───────────────────────────────────────────────────────────
@@ -605,9 +606,229 @@ function contentDispatch(funcName, args) {
     if (!el) throw new Error(`No element: ${selector}`);
     return JSON.parse(el.textContent);
   }
+  function extractMarkdown({ selector }) {
+    const BLOCKS = new Set([
+      "article", "aside", "blockquote", "body", "div", "dl", "fieldset", "figcaption",
+      "figure", "footer", "form", "h1", "h2", "h3", "h4", "h5", "h6", "header", "hr",
+      "li", "main", "nav", "ol", "p", "pre", "section", "table", "tbody", "td", "tfoot",
+      "th", "thead", "tr", "ul"
+    ]);
+
+    function normalizeText(value) {
+      return value.replace(/\s+/g, " ").trim();
+    }
+
+    function normalizeInline(value) {
+      return value
+        .replace(/[ \t]+\n/g, "\n")
+        .replace(/\n[ \t]+/g, "\n")
+        .replace(/\n{3,}/g, "\n\n")
+        .replace(/[ \t]{2,}/g, " ")
+        .trim();
+    }
+
+    function collapseBlankLines(value) {
+      return value
+        .replace(/[ \t]+\n/g, "\n")
+        .replace(/\n{3,}/g, "\n\n")
+        .trim();
+    }
+
+    function escapeMarkdown(text) {
+      return text.replace(/([\\`*_{}\[\]()#+\-!|>])/g, "\\$1");
+    }
+
+    function escapeTableCell(text) {
+      return text.replace(/\|/g, "\\|").replace(/\n+/g, " ").trim();
+    }
+
+    function absoluteUrl(attr, fallback) {
+      return attr || fallback || "";
+    }
+
+    function stripNoise(root) {
+      const clone = root.cloneNode(true);
+      clone.querySelectorAll("script, style, noscript, template").forEach(node => node.remove());
+      return clone;
+    }
+
+    function pickRoot() {
+      if (selector) {
+        const matched = document.querySelector(selector);
+        if (!matched) throw new Error(`No element: ${selector}`);
+        return matched;
+      }
+
+      const candidates = Array.from(document.querySelectorAll("main, article, [role='main']"))
+        .filter(node => normalizeText(node.innerText || "").length > 0);
+      if (!candidates.length) return document.body;
+      candidates.sort((a, b) => (b.innerText || "").length - (a.innerText || "").length);
+      return candidates[0];
+    }
+
+    function inlineText(node) {
+      if (node.nodeType === Node.TEXT_NODE) {
+        return escapeMarkdown(node.textContent || "");
+      }
+      if (node.nodeType !== Node.ELEMENT_NODE) return "";
+
+      const tag = node.tagName.toLowerCase();
+      if (tag === "script" || tag === "style" || tag === "noscript" || tag === "template") return "";
+      if (tag === "br") return "\n";
+      if (tag === "img") {
+        const src = absoluteUrl(node.getAttribute("src"), node.src);
+        if (!src) return "";
+        const alt = normalizeText(node.getAttribute("alt") || "");
+        return alt ? `![${escapeMarkdown(alt)}](${src})` : `![](${src})`;
+      }
+      if (tag === "a") {
+        const text = normalizeInline(Array.from(node.childNodes).map(inlineText).join(""));
+        const href = absoluteUrl(node.getAttribute("href"), node.href);
+        if (!href) return text;
+        return `[${text || href}](${href})`;
+      }
+      if (tag === "code") {
+        const text = normalizeInline(Array.from(node.childNodes).map(inlineText).join(""));
+        return text ? `\`${text.replace(/`/g, "\\`")}\`` : "";
+      }
+      if (tag === "strong" || tag === "b") {
+        const text = normalizeInline(Array.from(node.childNodes).map(inlineText).join(""));
+        return text ? `**${text}**` : "";
+      }
+      if (tag === "em" || tag === "i") {
+        const text = normalizeInline(Array.from(node.childNodes).map(inlineText).join(""));
+        return text ? `*${text}*` : "";
+      }
+
+      const chunks = [];
+      for (const child of node.childNodes) {
+        const rendered = inlineText(child);
+        if (!rendered) continue;
+        chunks.push(rendered);
+        if (child.nodeType === Node.ELEMENT_NODE && BLOCKS.has(child.tagName.toLowerCase())) {
+          chunks.push("\n");
+        }
+      }
+      return chunks.join("");
+    }
+
+    function textBlock(node) {
+      return collapseBlankLines(normalizeInline(Array.from(node.childNodes).map(inlineText).join("")));
+    }
+
+    function tableToMarkdown(table) {
+      const rows = Array.from(table.querySelectorAll("tr"))
+        .map(row => Array.from(row.children)
+          .filter(cell => cell.tagName === "TD" || cell.tagName === "TH")
+          .map(cell => escapeTableCell(textBlock(cell)))
+        )
+        .filter(cells => cells.length > 0);
+      if (!rows.length) return "";
+
+      const widths = rows.reduce((max, row) => Math.max(max, row.length), 0);
+      const normalizedRows = rows.map(row => {
+        const next = row.slice();
+        while (next.length < widths) next.push("");
+        return next;
+      });
+
+      let headers = normalizedRows[0];
+      let bodyRows = normalizedRows.slice(1);
+      const firstRow = table.querySelector("tr");
+      const thead = table.querySelector("thead");
+      const firstRowHasTh = firstRow && Array.from(firstRow.children).some(cell => cell.tagName === "TH");
+      if (!(thead || firstRowHasTh)) {
+        headers = new Array(widths).fill("");
+        bodyRows = normalizedRows;
+      }
+
+      const separator = new Array(widths).fill("---");
+      const lines = [
+        `| ${headers.join(" | ")} |`,
+        `| ${separator.join(" | ")} |`,
+      ];
+      for (const row of bodyRows) {
+        lines.push(`| ${row.join(" | ")} |`);
+      }
+      return lines.join("\n");
+    }
+
+    function listToMarkdown(list, depth = 0) {
+      const ordered = list.tagName.toLowerCase() === "ol";
+      const items = [];
+      const children = Array.from(list.children).filter(child => child.tagName === "LI");
+      children.forEach((item, index) => {
+        const marker = ordered ? `${index + 1}. ` : "- ";
+        const indent = "  ".repeat(depth);
+        const nested = [];
+        const content = [];
+
+        for (const child of item.childNodes) {
+          if (child.nodeType === Node.ELEMENT_NODE && (child.tagName === "UL" || child.tagName === "OL")) {
+            nested.push(listToMarkdown(child, depth + 1));
+          } else {
+            content.push(inlineText(child));
+          }
+        }
+
+        const line = collapseBlankLines(normalizeInline(content.join("")));
+        if (line) items.push(`${indent}${marker}${line}`);
+        nested.filter(Boolean).forEach(block => items.push(block));
+      });
+      return items.join("\n");
+    }
+
+    function blockToMarkdown(node) {
+      if (node.nodeType === Node.TEXT_NODE) {
+        return normalizeText(node.textContent || "");
+      }
+      if (node.nodeType !== Node.ELEMENT_NODE) return "";
+
+      const tag = node.tagName.toLowerCase();
+      if (tag === "script" || tag === "style" || tag === "noscript" || tag === "template") return "";
+      if (tag === "table") return tableToMarkdown(node);
+      if (tag === "ul" || tag === "ol") return listToMarkdown(node);
+      if (tag === "pre") {
+        const code = node.innerText.replace(/\n$/, "");
+        return code ? `\`\`\`\n${code}\n\`\`\`` : "";
+      }
+      if (tag === "blockquote") {
+        const content = collapseBlankLines(Array.from(node.childNodes).map(blockToMarkdown).join("\n\n"));
+        return content
+          .split("\n")
+          .map(line => line ? `> ${line}` : ">")
+          .join("\n");
+      }
+      if (/^h[1-6]$/.test(tag)) {
+        const level = Number(tag.slice(1));
+        const text = textBlock(node);
+        return text ? `${"#".repeat(level)} ${text}` : "";
+      }
+      if (tag === "p" || tag === "figcaption") {
+        return textBlock(node);
+      }
+      if (tag === "hr") {
+        return "---";
+      }
+      if (tag === "img") {
+        return inlineText(node);
+      }
+
+      const childBlocks = Array.from(node.childNodes)
+        .map(child => blockToMarkdown(child))
+        .filter(Boolean);
+      if (childBlocks.length) return collapseBlankLines(childBlocks.join("\n\n"));
+
+      return textBlock(node);
+    }
+
+    const root = stripNoise(pickRoot());
+    const markdown = blockToMarkdown(root);
+    return collapseBlankLines(markdown);
+  }
 
   const fns = { domQuery, domClick, domType, domAttr, domText, domExists,
-                 extractLinks, extractImages, extractText, extractJson };
+                 extractLinks, extractImages, extractText, extractJson, extractMarkdown };
   const fn = fns[funcName];
   if (!fn) throw new Error(`Unknown content function: ${funcName}`);
   return fn(args);
diff --git a/pyproject.toml b/pyproject.toml
index 0fa9f9c..6724caf 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "browser-cli"
-version = "0.4.1"
+version = "0.5.0"
 description = "Control your real running browser from the terminal via a Chrome extension"
 requires-python = ">=3.10"
 dependencies = [
diff --git a/tests/test_api.py b/tests/test_api.py
index 2199592..9cdc336 100644
--- a/tests/test_api.py
+++ b/tests/test_api.py
@@ -182,6 +182,21 @@ class TestSearch:
         assert mock_send.call_args[0][1]["background"] is True
 
 
+class TestExtract:
+    def test_extract_markdown_default(self, b, mock_send):
+        mock_send.return_value = "# Title"
+
+        result = b.extract_markdown()
+
+        assert result == "# Title"
+        mock_send.assert_called_once_with("extract.markdown", {"selector": None}, profile=None)
+
+    def test_extract_markdown_selector(self, b, mock_send):
+        b.extract_markdown("article")
+
+        mock_send.assert_called_once_with("extract.markdown", {"selector": "article"}, profile=None)
+
+
 # ── Tabs ──────────────────────────────────────────────────────────────────────
 
 class TestTabs:
diff --git a/tests/test_cli.py b/tests/test_cli.py
index 74c771f..0485378 100644
--- a/tests/test_cli.py
+++ b/tests/test_cli.py
@@ -54,3 +54,19 @@ def test_clients_exits_cleanly_when_registry_is_missing():
 
     assert result.exit_code == 1
     assert "No browser clients found" in result.output
+
+def test_extract_markdown_command():
+    with patch("browser_cli.commands.extract.send_command", return_value="# Title\n") as send_command:
+        result = CliRunner().invoke(main, ["extract", "markdown"])
+
+    assert result.exit_code == 0
+    assert result.output == "# Title\n"
+    send_command.assert_called_once_with("extract.markdown", {"selector": None})
+
+def test_extract_markdown_command_with_selector():
+    with patch("browser_cli.commands.extract.send_command", return_value="## Post\n") as send_command:
+        result = CliRunner().invoke(main, ["extract", "markdown", "--selector", "article"])
+
+    assert result.exit_code == 0
+    assert result.output == "## Post\n"
+    send_command.assert_called_once_with("extract.markdown", {"selector": "article"})
diff --git a/tests/test_extract.py b/tests/test_extract.py
index b1e26ee..df9a6fb 100644
--- a/tests/test_extract.py
+++ b/tests/test_extract.py
@@ -7,18 +7,24 @@ def test_extract_links(browser, http_tab):
     browser("tabs.active", {"tabId": http_tab["id"]})
     links = browser("extract.links")
     assert isinstance(links, list)
+    hrefs = []
     for lnk in links:
         assert "href" in lnk
         assert "text" in lnk
+        hrefs.append(lnk["href"])
+    assert len(hrefs) == len(set(hrefs))
 
 
 def test_extract_images(browser, http_tab):
     browser("tabs.active", {"tabId": http_tab["id"]})
     images = browser("extract.images")
     assert isinstance(images, list)
+    sources = []
     for img in images:
         assert "src" in img
         assert img["src"] != ""
+        sources.append(img["src"])
+    assert len(sources) == len(set(sources))
 
 
 def test_extract_text(browser, http_tab):
@@ -35,6 +41,19 @@ def test_extract_html(browser, http_tab):
     assert "<" in html
 
 
+def test_extract_markdown(browser, http_tab):
+    browser("tabs.active", {"tabId": http_tab["id"]})
+    markdown = browser("extract.markdown")
+    assert isinstance(markdown, str)
+    assert len(markdown.strip()) > 0
+
+
+def test_extract_markdown_missing_selector_errors(browser, http_tab):
+    browser("tabs.active", {"tabId": http_tab["id"]})
+    with pytest.raises(RuntimeError, match="No element"):
+        browser("extract.markdown", {"selector": ".browser-cli-definitely-missing"})
+
+
 def test_dom_exists(browser, http_tab):
     browser("tabs.active", {"tabId": http_tab["id"]})
     result = browser("dom.exists", {"selector": "body"})