diff --git a/bookmarks/frontend/components/dev-tool.js b/bookmarks/frontend/components/dev-tool.js
new file mode 100644
index 0000000..3e51509
--- /dev/null
+++ b/bookmarks/frontend/components/dev-tool.js
@@ -0,0 +1,257 @@
+import { LitElement, html, css } from "lit";
+
+class DevTool extends LitElement {
+  static properties = {
+    profile: { type: Object, state: true },
+    formAction: { type: String, attribute: "data-form-action" },
+    csrfToken: { type: String, attribute: "data-csrf-token" },
+    isOpen: { type: Boolean, state: true },
+  };
+
+  static styles = css`
+    :host {
+      position: fixed;
+      bottom: 1rem;
+      right: 1rem;
+      z-index: 10000;
+    }
+
+    .button {
+      background: var(--btn-primary-bg-color);
+      color: var(--btn-primary-text-color);
+      border: none;
+      padding: var(--unit-2);
+      border-radius: var(--border-radius);
+      box-shadow: var(--btn-box-shadow);
+      cursor: pointer;
+      height: auto;
+      line-height: 0;
+    }
+
+    .overlay {
+      display: none;
+      position: absolute;
+      bottom: 100%;
+      right: 0;
+      background: var(--body-color);
+      color: var(--text-color);
+      border: 1px solid var(--border-color);
+      border-radius: var(--border-radius);
+      padding: var(--unit-2);
+      margin-bottom: var(--unit-2);
+      min-width: 220px;
+      box-shadow: var(--box-shadow-lg);
+      font-size: var(--font-size-sm);
+    }
+
+    :host([open]) .overlay {
+      display: block;
+    }
+
+    h3 {
+      margin: 0 0 var(--unit-2) 0;
+    }
+
+    label {
+      display: flex;
+      align-items: center;
+      gap: var(--unit-1);
+      cursor: pointer;
+    }
+
+    label:has(select) {
+      margin-bottom: var(--unit-1);
+    }
+
+    label:has(select) span {
+      min-width: 100px;
+    }
+
+    hr {
+      margin: var(--unit-2) 0;
+      border: none;
+      border-top: 1px solid var(--border-color);
+    }
+  `;
+
+  static fields = [
+    {
+      type: "select",
+      key: "theme",
+      label: "Theme",
+      options: [
+        { value: "auto", label: "Auto" },
+        { value: "light", label: "Light" },
+        { value: "dark", label: "Dark" },
+      ],
+    },
+    {
+      type: "select",
+      key: "bookmark_date_display",
+      label: "Date",
+      options: [
+        { value: "relative", label: "Relative" },
+        { value: "absolute", label: "Absolute" },
+        { value: "hidden", label: "Hidden" },
+      ],
+    },
+    {
+      type: "select",
+      key: "bookmark_description_display",
+      label: "Description",
+      options: [
+        { value: "inline", label: "Inline" },
+        { value: "separate", label: "Separate" },
+      ],
+    },
+    { type: "checkbox", key: "enable_favicons", label: "Favicons" },
+    { type: "checkbox", key: "enable_preview_images", label: "Preview images" },
+    { type: "checkbox", key: "display_url", label: "Display URL" },
+    { type: "checkbox", key: "permanent_notes", label: "Permanent notes" },
+    { type: "checkbox", key: "collapse_side_panel", label: "Collapse sidebar" },
+    { type: "checkbox", key: "sticky_pagination", label: "Sticky pagination" },
+    { type: "checkbox", key: "hide_bundles", label: "Hide bundles" },
+  ];
+
+  constructor() {
+    super();
+    this.isOpen = false;
+    this.profile = {};
+    this._onOutsideClick = this._onOutsideClick.bind(this);
+  }
+
+  connectedCallback() {
+    super.connectedCallback();
+    const profileData = document.getElementById("json_profile");
+    this.profile = JSON.parse(profileData.textContent || "{}");
+    document.addEventListener("click", this._onOutsideClick);
+  }
+
+  disconnectedCallback() {
+    super.disconnectedCallback();
+    document.removeEventListener("click", this._onOutsideClick);
+  }
+
+  _onOutsideClick(e) {
+    if (!this.contains(e.target) && this.isOpen) {
+      this.isOpen = false;
+      this.removeAttribute("open");
+    }
+  }
+
+  _toggle() {
+    this.isOpen = !this.isOpen;
+    if (this.isOpen) {
+      this.setAttribute("open", "");
+    } else {
+      this.removeAttribute("open");
+    }
+  }
+
+  _handleChange(key, value) {
+    this.profile = { ...this.profile, [key]: value };
+    if (key === "theme") {
+      const themeLinks = document.head.querySelectorAll('link[href*="theme"]');
+      themeLinks.forEach((link) => link.remove());
+    }
+    this._submitForm();
+  }
+
+  _renderField(field) {
+    switch (field.type) {
+      case "checkbox":
+        return html`
+          <label>
+            <input
+              type="checkbox"
+              .checked=${this.profile[field.key] || false}
+              @change=${(e) => this._handleChange(field.key, e.target.checked)}
+            />
+            ${field.label}
+          </label>
+        `;
+      case "select":
+        return html`
+          <label>
+            <span>${field.label}:</span>
+            <select
+              @change=${(e) => this._handleChange(field.key, e.target.value)}
+            >
+              ${field.options.map(
+                (opt) => html`
+                  <option
+                    value=${opt.value}
+                    ?selected=${this.profile[field.key] === opt.value}
+                  >
+                    ${opt.label}
+                  </option>
+                `,
+              )}
+            </select>
+          </label>
+        `;
+      case "divider":
+        return html`<hr />`;
+      default:
+        return null;
+    }
+  }
+
+  async _submitForm() {
+    const formData = new FormData();
+    formData.append("csrfmiddlewaretoken", this.csrfToken);
+
+    // Profile fields
+    for (const [key, value] of Object.entries(this.profile)) {
+      if (typeof value === "boolean" && value) {
+        formData.append(key, "on");
+      } else if (typeof value !== "boolean") {
+        formData.append(key, value);
+      }
+    }
+
+    // Submit button name that settings.update expects
+    formData.append("update_profile", "1");
+
+    await fetch(this.formAction, {
+      method: "POST",
+      body: formData,
+    });
+
+    const url = new URL(window.location);
+    url.searchParams.set("ts", Date.now().toString());
+    window.history.replaceState({}, "", url);
+
+    Turbo.visit(url.toString());
+  }
+
+  render() {
+    return html`
+      <button class="button" @click=${() => this._toggle()}>
+        <svg
+          xmlns="http://www.w3.org/2000/svg"
+          width="24"
+          height="24"
+          viewBox="0 0 24 24"
+          fill="none"
+          stroke="currentColor"
+          stroke-width="2"
+          stroke-linecap="round"
+          stroke-linejoin="round"
+        >
+          <path stroke="none" d="M0 0h24v24H0z" fill="none" />
+          <path
+            d="M10.325 4.317c.426 -1.756 2.924 -1.756 3.35 0a1.724 1.724 0 0 0 2.573 1.066c1.543 -.94 3.31 .826 2.37 2.37a1.724 1.724 0 0 0 1.065 2.572c1.756 .426 1.756 2.924 0 3.35a1.724 1.724 0 0 0 -1.066 2.573c.94 1.543 -.826 3.31 -2.37 2.37a1.724 1.724 0 0 0 -2.572 1.065c-.426 1.756 -2.924 1.756 -3.35 0a1.724 1.724 0 0 0 -2.573 -1.066c-1.543 .94 -3.31 -.826 -2.37 -2.37a1.724 1.724 0 0 0 -1.065 -2.572c-1.756 -.426 -1.756 -2.924 0 -3.35a1.724 1.724 0 0 0 1.066 -2.573c-.94 -1.543 .826 -3.31 2.37 -2.37c1 .608 2.296 .07 2.572 -1.065"
+          />
+          <path d="M9 12a3 3 0 1 0 6 0a3 3 0 0 0 -6 0" />
+        </svg>
+      </button>
+      <div class="overlay">
+        <h3>Dev Tools</h3>
+        ${DevTool.fields.map((field) => this._renderField(field))}
+      </div>
+    `;
+  }
+}
+
+customElements.define("ld-dev-tool", DevTool);
diff --git a/bookmarks/frontend/index.js b/bookmarks/frontend/index.js
index 5639a52..3b5d3f8 100644
--- a/bookmarks/frontend/index.js
+++ b/bookmarks/frontend/index.js
@@ -3,6 +3,7 @@ import "./components/bookmark-page.js";
 import "./components/clear-button.js";
 import "./components/confirm-dropdown.js";
 import "./components/details-modal.js";
+import "./components/dev-tool.js";
 import "./components/dropdown.js";
 import "./components/filter-drawer.js";
 import "./components/form.js";
diff --git a/bookmarks/templates/shared/dev_tool.html b/bookmarks/templates/shared/dev_tool.html
new file mode 100644
index 0000000..b932cda
--- /dev/null
+++ b/bookmarks/templates/shared/dev_tool.html
@@ -0,0 +1,9 @@
+{% load shared %}
+{% if debug and request.user.is_authenticated %}
+  {{ request.user.profile|model_to_dict|json_script:"json_profile" }}
+  <ld-dev-tool id="dev-tool"
+               data-csrf-token="{{ csrf_token }}"
+               data-form-action="{% url 'linkding:settings.update' %}"
+               data-turbo-permanent>
+  </ld-dev-tool>
+{% endif %}
diff --git a/bookmarks/templates/shared/layout.html b/bookmarks/templates/shared/layout.html
index 3500694..0a44714 100644
--- a/bookmarks/templates/shared/layout.html
+++ b/bookmarks/templates/shared/layout.html
@@ -46,5 +46,6 @@
     <div class="modals">
       {% block overlays %}{% endblock %}
     </div>
+    {% include 'shared/dev_tool.html' %}
   </body>
 </html>
diff --git a/bookmarks/templatetags/shared.py b/bookmarks/templatetags/shared.py
index 40676ab..04a3d8a 100644
--- a/bookmarks/templatetags/shared.py
+++ b/bookmarks/templatetags/shared.py
@@ -5,6 +5,7 @@ import markdown
 from bleach.linkifier import DEFAULT_CALLBACKS, Linker
 from bleach_allowlist import markdown_attrs, markdown_tags
 from django import template
+from django.forms.models import model_to_dict
 from django.utils.safestring import mark_safe
 
 from bookmarks import utils
@@ -60,6 +61,12 @@ def humanize_relative_date(value):
     return utils.humanize_relative_date(value)
 
 
+@register.filter(name="model_to_dict")
+def model_to_dict_filter(value):
+    result = model_to_dict(value)
+    return result
+
+
 @register.tag
 def htmlmin(parser, token):
     nodelist = parser.parse(("endhtmlmin",))
diff --git a/rollup.config.mjs b/rollup.config.mjs
index 7394394..17e9b0e 100644
--- a/rollup.config.mjs
+++ b/rollup.config.mjs
@@ -3,6 +3,17 @@ import terser from '@rollup/plugin-terser';
 
 const production = !process.env.ROLLUP_WATCH;
 
+// Custom plugin to exclude dev-tool.js from production builds
+const excludeDevTool = {
+  name: 'exclude-dev-tool',
+  load(id) {
+    if (production && id.endsWith('dev-tool.js')) {
+      return '';
+    }
+    return null;
+  },
+};
+
 export default {
   input: 'bookmarks/frontend/index.js',
   output: {
@@ -13,6 +24,7 @@ export default {
     file: 'bookmarks/static/bundle.js',
   },
   plugins: [
+    excludeDevTool,
     // If you have external dependencies installed from
     // npm, you'll most likely need these plugins. In
     // some cases you'll need additional configuration —