diff --git a/browser/components/urlbar/tests/browser/browser.ini b/browser/components/urlbar/tests/browser/browser.ini
index 1109b8b61d1c..3d8ee03fdcd5 100644
--- a/browser/components/urlbar/tests/browser/browser.ini
+++ b/browser/components/urlbar/tests/browser/browser.ini
@@ -251,6 +251,7 @@ support-files =
 [browser_top_sites.js]
 [browser_top_sites_private.js]
 [browser_typed_value.js]
+[browser_unitConversion.js]
 [browser_updateForDomainCompletion.js]
 [browser_urlbar_event_telemetry.js]
 support-files =
diff --git a/browser/components/urlbar/tests/browser/browser_unitConversion.js b/browser/components/urlbar/tests/browser/browser_unitConversion.js
new file mode 100644
index 000000000000..a8cc345d792e
--- /dev/null
+++ b/browser/components/urlbar/tests/browser/browser_unitConversion.js
@@ -0,0 +1,88 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+/**
+ * Tests unit conversion on browser.
+ */
+
+add_task(async function setup() {
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      ["browser.urlbar.unitConversion.enabled", true],
+      // There are cases that URLBar loses focus before assertion of this test.
+      // In that case, this test will be failed since the result is closed
+      // before it. We use this pref so that keep the result even if lose focus.
+      ["ui.popup.disable_autohide", true],
+    ],
+  });
+
+  registerCleanupFunction(function() {
+    SpecialPowers.clipboardCopyString("");
+  });
+});
+
+add_task(async function test_selectByMouse() {
+  // Clear clipboard content.
+  SpecialPowers.clipboardCopyString("");
+
+  const row = await doUnitConversion();
+
+  info("Check if the result is copied to clipboard when selecting by mouse");
+  EventUtils.synthesizeMouseAtCenter(
+    row.querySelector(".urlbarView-no-wrap"),
+    {},
+    window
+  );
+  assertClipboard();
+
+  await UrlbarTestUtils.promisePopupClose(window);
+});
+
+add_task(async function test_selectByKey() {
+  // Clear clipboard content.
+  SpecialPowers.clipboardCopyString("");
+
+  await doUnitConversion();
+
+  // As gURLBar might lost focus,
+  // give focus again in order to enable key event on the result.
+  gURLBar.focus();
+
+  info("Check if the result is copied to clipboard when selecting by key");
+  EventUtils.synthesizeKey("KEY_ArrowDown");
+  EventUtils.synthesizeKey("KEY_Enter");
+  assertClipboard();
+
+  await UrlbarTestUtils.promisePopupClose(window);
+});
+
+function assertClipboard() {
+  Assert.equal(
+    SpecialPowers.getClipboardData("text/unicode"),
+    "100 cm",
+    "The result of conversion is copied to clipboard"
+  );
+}
+
+async function doUnitConversion() {
+  info("Do unit conversion then wait the result");
+
+  await UrlbarTestUtils.promiseAutocompleteResultPopup({
+    window,
+    value: "1m to cm",
+    waitForFocus: SimpleTest.waitForFocus,
+  });
+
+  const row = await UrlbarTestUtils.waitForAutocompleteResultAt(window, 1);
+
+  Assert.ok(row.querySelector(".urlbarView-favicon"), "The icon is displayed");
+  Assert.equal(
+    row.querySelector(".urlbarView-dynamic-unitConversion-output").textContent,
+    "100 cm",
+    "The unit is converted"
+  );
+
+  return row;
+}
diff --git a/browser/components/urlbar/tests/unit/test_unitConversion.js b/browser/components/urlbar/tests/unit/test_unitConversion.js
new file mode 100644
index 000000000000..5c93d0632760
--- /dev/null
+++ b/browser/components/urlbar/tests/unit/test_unitConversion.js
@@ -0,0 +1,497 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Unit test for unit conversion module.
+ */
+
+XPCOMUtils.defineLazyModuleGetters(this, {
+  UrlbarProviderUnitConversion:
+    "resource:///modules/UrlbarProviderUnitConversion.jsm",
+});
+
+const TEST_DATA = [
+  {
+    category: "angle",
+    cases: [
+      { queryString: "1 d to d", expected: "1 deg" },
+      { queryString: "1 d in d", expected: "1 deg" },
+      { queryString: "1 d = d", expected: "1 deg" },
+      { queryString: "1 D=D", expected: "1 deg" },
+      { queryString: "1 d to degree", expected: "1 deg" },
+      { queryString: "2 d to degree", expected: "2 deg" },
+      {
+        queryString: "1 d to radian",
+        expected: `${round(Math.PI / 180)} radian`,
+      },
+      {
+        queryString: "2 d to radian",
+        expected: `${round((Math.PI / 180) * 2)} radian`,
+      },
+      { queryString: "1 d to rad", expected: `${round(Math.PI / 180)} radian` },
+      { queryString: "1 d to r", expected: `${round(Math.PI / 180)} radian` },
+      { queryString: "1 d to gradian", expected: `${round(1 / 0.9)} gradian` },
+      { queryString: "1 d to g", expected: `${round(1 / 0.9)} gradian` },
+      { queryString: "1 d to minute", expected: "60 min" },
+      { queryString: "1 d to min", expected: "60 min" },
+      { queryString: "1 d to m", expected: "60 min" },
+      { queryString: "1 d to second", expected: "3,600 sec" },
+      { queryString: "1 d to sec", expected: "3,600 sec" },
+      { queryString: "1 d to s", expected: "3,600 sec" },
+      { queryString: "1 d to sign", expected: `${round(1 / 30)} sign` },
+      { queryString: "1 d to mil", expected: `${round(1 / 0.05625)} mil` },
+      {
+        queryString: "1 d to revolution",
+        expected: `${round(1 / 360)} revolution`,
+      },
+      { queryString: "1 d to circle", expected: `${round(1 / 360)} circle` },
+      { queryString: "1 d to turn", expected: `${round(1 / 360)} turn` },
+      { queryString: "1 d to quadrant", expected: `${round(1 / 90)} quadrant` },
+      {
+        queryString: "1 d to rightangle",
+        expected: `${round(1 / 90)} rightangle`,
+      },
+      { queryString: "1 d to sextant", expected: `${round(1 / 60)} sextant` },
+      { queryString: "1 degree to d", expected: "1 deg" },
+      { queryString: "1 radian to d", expected: `${round(180 / Math.PI)} deg` },
+      {
+        queryString: "1 r to g",
+        expected: `${round(180 / Math.PI / 0.9)} gradian`,
+      },
+    ],
+  },
+  {
+    category: "force",
+    cases: [
+      { queryString: "1 n to n", expected: "1 newton" },
+      { queryString: "1 n in n", expected: "1 newton" },
+      { queryString: "1 n = n", expected: "1 newton" },
+      { queryString: "1 N=N", expected: "1 newton" },
+      { queryString: "1 n to newton", expected: "1 newton" },
+      { queryString: "1 n to kilonewton", expected: "0.001 kilonewton" },
+      { queryString: "1 n to kn", expected: "0.001 kilonewton" },
+      {
+        queryString: "1 n to gram-force",
+        expected: `${round(101.9716213)} gram-force`,
+      },
+      {
+        queryString: "1 n to gf",
+        expected: `${round(101.9716213)} gram-force`,
+      },
+      {
+        queryString: "1 n to kilogram-force",
+        expected: `${round(0.1019716213)} kilogram-force`,
+      },
+      {
+        queryString: "1 n to kgf",
+        expected: `${round(0.1019716213)} kilogram-force`,
+      },
+      {
+        queryString: "1 n to ton-force",
+        expected: `${round(0.0001019716213)} ton-force`,
+      },
+      {
+        queryString: "1 n to tf",
+        expected: `${round(0.0001019716213)} ton-force`,
+      },
+      {
+        queryString: "1 n to exanewton",
+        expected: `${round(1.0e-18)} exanewton`,
+      },
+      { queryString: "1 n to en", expected: `${round(1.0e-18)} exanewton` },
+      {
+        queryString: "1 n to petanewton",
+        expected: `${round(1.0e-15)} petanewton`,
+      },
+      { queryString: "1 n to PN", expected: `${round(1.0e-15)} petanewton` },
+      { queryString: "1 n to Pn", expected: `${round(1.0e-15)} petanewton` },
+      {
+        queryString: "1 n to teranewton",
+        expected: `${round(1.0e-12)} teranewton`,
+      },
+      { queryString: "1 n to tn", expected: `${round(1.0e-12)} teranewton` },
+      {
+        queryString: "1 n to giganewton",
+        expected: `${round(1.0e-9)} giganewton`,
+      },
+      { queryString: "1 n to gn", expected: `${round(1.0e-9)} giganewton` },
+      { queryString: "1 n to meganewton", expected: "0.000001 meganewton" },
+      { queryString: "1 n to MN", expected: "0.000001 meganewton" },
+      { queryString: "1 n to Mn", expected: "0.000001 meganewton" },
+      { queryString: "1 n to hectonewton", expected: "0.01 hectonewton" },
+      { queryString: "1 n to hn", expected: "0.01 hectonewton" },
+      { queryString: "1 n to dekanewton", expected: "0.1 dekanewton" },
+      { queryString: "1 n to dan", expected: "0.1 dekanewton" },
+      { queryString: "1 n to decinewton", expected: "10 decinewton" },
+      { queryString: "1 n to dn", expected: "10 decinewton" },
+      { queryString: "1 n to centinewton", expected: "100 centinewton" },
+      { queryString: "1 n to cn", expected: "100 centinewton" },
+      { queryString: "1 n to millinewton", expected: "1000 millinewton" },
+      { queryString: "1 n to mn", expected: "1000 millinewton" },
+      { queryString: "1 n to micronewton", expected: "1000000 micronewton" },
+      { queryString: "1 n to µn", expected: "1000000 micronewton" },
+      {
+        queryString: "1 n to nanonewton",
+        expected: "1000000000 nanonewton",
+      },
+      { queryString: "1 n to nn", expected: "1000000000 nanonewton" },
+      {
+        queryString: "1 n to piconewton",
+        expected: "1000000000000 piconewton",
+      },
+      { queryString: "1 n to pn", expected: "1000000000000 piconewton" },
+      {
+        queryString: "1 n to femtonewton",
+        expected: "1000000000000000 femtonewton",
+      },
+      { queryString: "1 n to fn", expected: "1000000000000000 femtonewton" },
+      {
+        queryString: "1 n to attonewton",
+        expected: "1000000000000000000 attonewton",
+      },
+      { queryString: "1 n to an", expected: "1000000000000000000 attonewton" },
+      { queryString: "1 n to dyne", expected: "100000 dyne" },
+      { queryString: "1 n to dyn", expected: "100000 dyne" },
+      { queryString: "1 n to joule/meter", expected: "1 joule/meter" },
+      { queryString: "1 n to j/m", expected: "1 joule/meter" },
+      {
+        queryString: "1 n to joule/centimeter",
+        expected: "100 joule/centimeter",
+      },
+      { queryString: "1 n to j/cm", expected: "100 joule/centimeter" },
+      {
+        queryString: "1 n to ton-force-short",
+        expected: `${round(0.0001124045)} ton-force-short`,
+      },
+      {
+        queryString: "1 n to short",
+        expected: `${round(0.0001124045)} ton-force-short`,
+      },
+      {
+        queryString: "1 n to ton-force-long",
+        expected: `${round(0.0001003611)} ton-force-long`,
+      },
+      {
+        queryString: "1 n to tonf",
+        expected: `${round(0.0001003611)} ton-force-long`,
+      },
+      {
+        queryString: "1 n to kip-force",
+        expected: `${round(0.0002248089)} kip-force`,
+      },
+      {
+        queryString: "1 n to kipf",
+        expected: `${round(0.0002248089)} kip-force`,
+      },
+      {
+        queryString: "1 n to pound-force",
+        expected: `${round(0.2248089431)} pound-force`,
+      },
+      {
+        queryString: "1 n to lbf",
+        expected: `${round(0.2248089431)} pound-force`,
+      },
+      {
+        queryString: "1 n to ounce-force",
+        expected: `${round(3.5969430896)} ounce-force`,
+      },
+      {
+        queryString: "1 n to ozf",
+        expected: `${round(3.5969430896)} ounce-force`,
+      },
+      {
+        queryString: "1 n to poundal",
+        expected: `${round(7.2330138512)} poundal`,
+      },
+      { queryString: "1 n to pdl", expected: `${round(7.2330138512)} poundal` },
+      { queryString: "1 n to pond", expected: `${round(101.9716213)} pond` },
+      { queryString: "1 n to p", expected: `${round(101.9716213)} pond` },
+      {
+        queryString: "1 n to kilopond",
+        expected: `${round(0.1019716213)} kilopond`,
+      },
+      { queryString: "1 n to kp", expected: `${round(0.1019716213)} kilopond` },
+      { queryString: "1 kilonewton to n", expected: "1000 newton" },
+    ],
+  },
+  {
+    category: "length",
+    cases: [
+      { queryString: "1 meter to meter", expected: "1 m" },
+      { queryString: "1 meter in meter", expected: "1 m" },
+      { queryString: "1 meter = meter", expected: "1 m" },
+      { queryString: "1 METER=METER", expected: "1 m" },
+      { queryString: "1 m to meter", expected: "1 m" },
+      { queryString: "1 m to nanometer", expected: "1000000000 nanometer" },
+      { queryString: "1 m to micrometer", expected: "1000000 micrometer" },
+      { queryString: "1 m to millimeter", expected: "1,000 mm" },
+      { queryString: "1 m to mm", expected: "1,000 mm" },
+      { queryString: "1 m to centimeter", expected: "100 cm" },
+      { queryString: "1 m to cm", expected: "100 cm" },
+      { queryString: "1 m to kilometer", expected: "0.001 km" },
+      { queryString: "1 m to km", expected: "0.001 km" },
+      { queryString: "1 m to mile", expected: `${round(0.0006213689)} mi` },
+      { queryString: "1 m to mi", expected: `${round(0.0006213689)} mi` },
+      { queryString: "1 m to yard", expected: `${round(1.0936132983)} yd` },
+      { queryString: "1 m to yd", expected: `${round(1.0936132983)} yd` },
+      { queryString: "1 m to foot", expected: `${round(3.280839895)} ft` },
+      { queryString: "1 m to ft", expected: `${round(3.280839895)} ft` },
+      { queryString: "1 m to inch", expected: `${round(39.37007874)} in` },
+      { queryString: "1 inch to m", expected: `${round(1 / 39.37007874)} m` },
+    ],
+  },
+  {
+    category: "mass",
+    cases: [
+      { queryString: "1 kg to kg", expected: "1 kg" },
+      { queryString: "1 kg in kg", expected: "1 kg" },
+      { queryString: "1 kg = kg", expected: "1 kg" },
+      { queryString: "1 KG=KG", expected: "1 kg" },
+      { queryString: "1 kg to kilogram", expected: "1 kg" },
+      { queryString: "1 kg to gram", expected: "1,000 g" },
+      { queryString: "1 kg to g", expected: "1,000 g" },
+      { queryString: "1 kg to milligram", expected: "1000000 milligram" },
+      { queryString: "1 kg to mg", expected: "1000000 milligram" },
+      { queryString: "1 kg to ton", expected: "0.001 ton" },
+      { queryString: "1 kg to t", expected: "0.001 ton" },
+      {
+        queryString: "1 kg to longton",
+        expected: `${round(0.0009842073)} longton`,
+      },
+      {
+        queryString: "1 kg to l.t.",
+        expected: `${round(0.0009842073)} longton`,
+      },
+      {
+        queryString: "1 kg to l/t",
+        expected: `${round(0.0009842073)} longton`,
+      },
+      {
+        queryString: "1 kg to shortton",
+        expected: `${round(0.0011023122)} shortton`,
+      },
+      {
+        queryString: "1 kg to s.t.",
+        expected: `${round(0.0011023122)} shortton`,
+      },
+      {
+        queryString: "1 kg to s/t",
+        expected: `${round(0.0011023122)} shortton`,
+      },
+      {
+        queryString: "1 kg to pound",
+        expected: `${round(2.2046244202)} lb`,
+      },
+      { queryString: "1 kg to lbs", expected: `${round(2.2046244202)} lb` },
+      {
+        queryString: "1 kg to lb",
+        expected: `${round(2.2046244202)} lb`,
+      },
+      {
+        queryString: "1 kg to ounce",
+        expected: `${round(35.273990723)} oz`,
+      },
+      { queryString: "1 kg to oz", expected: `${round(35.273990723)} oz` },
+      { queryString: "1 kg to carat", expected: "5000 carat" },
+      { queryString: "1 kg to ffd", expected: "5000 ffd" },
+      { queryString: "1 ffd to kg", expected: `${round(1 / 5000)} kg` },
+    ],
+  },
+  {
+    category: "temperature",
+    cases: [
+      { queryString: "0 c to c", expected: "0°C" },
+      { queryString: "0 c in c", expected: "0°C" },
+      { queryString: "0 c = c", expected: "0°C" },
+      { queryString: "0 C=C", expected: "0°C" },
+      { queryString: "0 c to celsius", expected: "0°C" },
+      { queryString: "0 c to kelvin", expected: "273.15 kelvin" },
+      { queryString: "0 c to k", expected: "273.15 kelvin" },
+      { queryString: "10 c to k", expected: "283.15 kelvin" },
+      { queryString: "0 c to fahrenheit", expected: `${32 * 1.8}°F` },
+      { queryString: "0 c to f", expected: `${32 * 1.8}°F` },
+      { queryString: "10 c to f", expected: `${round((10 + 32) * 1.8)}°F` },
+      {
+        queryString: "10 f to kelvin",
+        expected: `${round((10 - 32) / 1.8 + 273.15)} kelvin`,
+      },
+    ],
+  },
+  {
+    category: "timezone",
+    cases: [
+      { queryString: "0 utc to utc", expected: "00:00 UTC" },
+      { queryString: "0 utc in utc", expected: "00:00 UTC" },
+      { queryString: "0 utc = utc", expected: "00:00 UTC" },
+      { queryString: "0 UTC=UTC", expected: "00:00 UTC" },
+      { queryString: "11 pm utc to utc", expected: "11:00 PM UTC" },
+      { queryString: "11 am utc to utc", expected: "11:00 AM UTC" },
+      { queryString: "11:30 utc to utc", expected: "11:30 UTC" },
+      { queryString: "11:30 PM utc to utc", expected: "11:30 PM UTC" },
+      { queryString: "1 utc to idlw", expected: "13:00 IDLW" },
+      { queryString: "1 pm utc to idlw", expected: "1:00 AM IDLW" },
+      { queryString: "1 am utc to idlw", expected: "1:00 PM IDLW" },
+      { queryString: "1 utc to idlw", expected: "13:00 IDLW" },
+      { queryString: "1 PM utc to idlw", expected: "1:00 AM IDLW" },
+      { queryString: "0 utc to nt", expected: "13:00 NT" },
+      { queryString: "0 utc to hst", expected: "14:00 HST" },
+      { queryString: "0 utc to akst", expected: "15:00 AKST" },
+      { queryString: "0 utc to pst", expected: "16:00 PST" },
+      { queryString: "0 utc to akdt", expected: "16:00 AKDT" },
+      { queryString: "0 utc to mst", expected: "17:00 MST" },
+      { queryString: "0 utc to pdt", expected: "17:00 PDT" },
+      { queryString: "0 utc to cst", expected: "18:00 CST" },
+      { queryString: "0 utc to mdt", expected: "18:00 MDT" },
+      { queryString: "0 utc to est", expected: "19:00 EST" },
+      { queryString: "0 utc to cdt", expected: "19:00 CDT" },
+      { queryString: "0 utc to edt", expected: "20:00 EDT" },
+      { queryString: "0 utc to ast", expected: "20:00 AST" },
+      { queryString: "0 utc to guy", expected: "21:00 GUY" },
+      { queryString: "0 utc to adt", expected: "21:00 ADT" },
+      { queryString: "0 utc to at", expected: "22:00 AT" },
+      { queryString: "0 utc to gmt", expected: "00:00 GMT" },
+      { queryString: "0 utc to z", expected: "00:00 Z" },
+      { queryString: "0 utc to wet", expected: "00:00 WET" },
+      { queryString: "0 utc to west", expected: "01:00 WEST" },
+      { queryString: "0 utc to cet", expected: "01:00 CET" },
+      { queryString: "0 utc to bst", expected: "01:00 BST" },
+      { queryString: "0 utc to ist", expected: "01:00 IST" },
+      { queryString: "0 utc to cest", expected: "02:00 CEST" },
+      { queryString: "0 utc to eet", expected: "02:00 EET" },
+      { queryString: "0 utc to eest", expected: "03:00 EEST" },
+      { queryString: "0 utc to msk", expected: "03:00 MSK" },
+      { queryString: "0 utc to msd", expected: "04:00 MSD" },
+      { queryString: "0 utc to zp4", expected: "04:00 ZP4" },
+      { queryString: "0 utc to zp5", expected: "05:00 ZP5" },
+      { queryString: "0 utc to zp6", expected: "06:00 ZP6" },
+      { queryString: "0 utc to wast", expected: "07:00 WAST" },
+      { queryString: "0 utc to awst", expected: "08:00 AWST" },
+      { queryString: "0 utc to wst", expected: "08:00 WST" },
+      { queryString: "0 utc to jst", expected: "09:00 JST" },
+      { queryString: "0 utc to acst", expected: "09:30 ACST" },
+      { queryString: "0 utc to aest", expected: "10:00 AEST" },
+      { queryString: "0 utc to acdt", expected: "10:30 ACDT" },
+      { queryString: "0 utc to aedt", expected: "11:00 AEDT" },
+      { queryString: "0 utc to nzst", expected: "12:00 NZST" },
+      { queryString: "0 utc to idle", expected: "12:00 IDLE" },
+      { queryString: "0 utc to nzd", expected: "13:00 NZD" },
+      { queryString: "9:00 jst to utc", expected: "00:00 UTC" },
+      { queryString: "8:00 jst to utc", expected: "23:00 UTC" },
+      { queryString: "8:00 am jst to utc", expected: "11:00 PM UTC" },
+      { queryString: "9:00 jst to pdt", expected: "17:00 PDT" },
+      {
+        queryString: "0:00 utc to here",
+        timezone: "EST5EDT",
+        expected: "20:00 UTC-400",
+      },
+      {
+        queryString: "0:00 utc to here",
+        timezone: "PST8PDT",
+        expected: "17:00 UTC-700",
+      },
+      {
+        queryString: "9:00 to utc",
+        timezone: "EST5EDT",
+        expected: "13:00 UTC",
+      },
+      {
+        queryString: "9 am to utc",
+        timezone: "EST5EDT",
+        expected: "1:00 PM UTC",
+      },
+      {
+        queryString: "now to utc",
+        timezone: "EST5EDT",
+        assertResult: output => {
+          const nowDate = new Date();
+          nowDate.setUTCMinutes(nowDate.getUTCMinutes() + 60 * 4);
+          const outputRegexResult = /([0-2]?[0-9]):([0-5][0-9])/.exec(output);
+          const outputDate = new Date();
+          outputDate.setUTCFullYear(nowDate.getUTCFullYear());
+          outputDate.setUTCMonth(nowDate.getUTCMonth());
+          outputDate.setUTCDate(nowDate.getUTCDate());
+          outputDate.setUTCHours(parseInt(outputRegexResult[1]));
+          outputDate.setUTCMinutes(parseInt(outputRegexResult[2]));
+
+          // The timing that output was evaluated is different,
+          // we have a buffer (1sec) for it, just to be safe.
+          Assert.ok(outputDate.getTime() <= nowDate.getTime() + 1000);
+        },
+      },
+      {
+        queryString: "now to here",
+        assertResult: output => {
+          const nowDate = new Date();
+          const outputRegexResult = /([0-2]?[0-9]):([0-5][0-9])/.exec(output);
+          const outputDate = new Date();
+          outputDate.setUTCFullYear(nowDate.getUTCFullYear());
+          outputDate.setUTCMonth(nowDate.getUTCMonth());
+          outputDate.setUTCDate(nowDate.getUTCDate());
+          outputDate.setUTCHours(parseInt(outputRegexResult[1]));
+          outputDate.setUTCMinutes(parseInt(outputRegexResult[2]));
+          Assert.ok(outputDate.getTime() <= nowDate.getTime() + 1000);
+        },
+      },
+    ],
+  },
+  {
+    category: "invalid",
+    cases: [
+      { queryString: "1 to cm" },
+      { queryString: "1cm to newton" },
+      { queryString: "1cm to foo" },
+      { queryString: "0:00:00 utc to jst" },
+    ],
+  },
+];
+
+add_task(function() {
+  // Enable unit conversion.
+  Services.prefs.setBoolPref("browser.urlbar.unitConversion.enabled", true);
+  registerCleanupFunction(() => {
+    Services.prefs.clearUserPref("browser.urlbar.unitConversion.enabled");
+  });
+
+  for (const { category, cases } of TEST_DATA) {
+    for (const { queryString, timezone, expected, assertResult } of cases) {
+      info(`Test "${queryString}" in ${category}`);
+
+      let originalTimezone;
+      if (timezone) {
+        originalTimezone = Cu.getJSTestingFunctions().getTimeZone();
+        info(`Set timezone ${timezone}`);
+        Cu.getJSTestingFunctions().setTimeZone(timezone);
+      }
+
+      const context = createContext(queryString);
+      const isActive = UrlbarProviderUnitConversion.isActive(context);
+      Assert.equal(isActive, !!expected || !!assertResult);
+
+      if (isActive) {
+        UrlbarProviderUnitConversion.startQuery(context, (module, result) => {
+          Assert.equal(result.type, UrlbarUtils.RESULT_TYPE.DYNAMIC);
+          Assert.equal(result.source, UrlbarUtils.RESULT_SOURCE.OTHER_LOCAL);
+          Assert.equal(result.suggestedIndex, 1);
+          Assert.equal(result.payload.input, queryString);
+
+          if (expected) {
+            Assert.equal(result.payload.output, expected);
+          } else {
+            assertResult(result.payload.output);
+          }
+        });
+      }
+
+      if (originalTimezone) {
+        Cu.getJSTestingFunctions().setTimeZone(originalTimezone);
+      }
+    }
+  }
+});
+
+function round(number) {
+  return parseFloat(number.toPrecision(10));
+}
diff --git a/browser/components/urlbar/tests/unit/xpcshell.ini b/browser/components/urlbar/tests/unit/xpcshell.ini
index 9ebebaaa4e35..4a30cf94deeb 100644
--- a/browser/components/urlbar/tests/unit/xpcshell.ini
+++ b/browser/components/urlbar/tests/unit/xpcshell.ini
@@ -45,6 +45,7 @@ skip-if = os == 'linux' # bug 1474616
 [test_quicksuggest_keywordtree.js]
 [test_tokenizer.js]
 [test_trimming.js]
+[test_unitConversion.js]
 [test_UrlbarController_integration.js]
 [test_UrlbarController_telemetry.js]
 [test_UrlbarController_unit.js]