diff --git a/ts/editor/BUILD.bazel b/ts/editor/BUILD.bazel
index d6fa1f88d..83770ab61 100644
--- a/ts/editor/BUILD.bazel
+++ b/ts/editor/BUILD.bazel
@@ -21,7 +21,7 @@ ts_library(
     srcs = glob(["*.ts"]),
     tsconfig = "//qt/aqt/data/web/js:tsconfig.json",
     deps = [
-        "@npm//@types/jquery",
+        "//ts/html-filter",
     ],
 )
 
diff --git a/ts/editor/helpers.ts b/ts/editor/helpers.ts
index 7493f6698..9281af818 100644
--- a/ts/editor/helpers.ts
+++ b/ts/editor/helpers.ts
@@ -7,10 +7,6 @@ export function nodeIsElement(node: Node): node is Element {
     return node.nodeType === Node.ELEMENT_NODE;
 }
 
-export function isHTMLElement(elem: Element): elem is HTMLElement {
-    return elem instanceof HTMLElement;
-}
-
 const INLINE_TAGS = [
     "A",
     "ABBR",
@@ -81,7 +77,3 @@ export function caretToEnd(currentField: EditingArea): void {
     selection.removeAllRanges();
     selection.addRange(range);
 }
-
-export function isNightMode(): boolean {
-    return document.body.classList.contains("nightMode");
-}
diff --git a/ts/editor/index.ts b/ts/editor/index.ts
index 0f0c87f2e..b6488e9b6 100644
--- a/ts/editor/index.ts
+++ b/ts/editor/index.ts
@@ -1,9 +1,10 @@
 /* Copyright: Ankitects Pty Ltd and contributors
  * License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html */
 
+import { filterHTML } from "html-filter/index";
+
 import { caretToEnd } from "./helpers";
 import { saveField } from "./changeTimer";
-import { filterHTML } from "./htmlFilter";
 import { updateButtonState, disableButtons } from "./toolbar";
 
 import { EditorField } from "./editorField";
diff --git a/ts/html-filter/BUILD.bazel b/ts/html-filter/BUILD.bazel
new file mode 100644
index 000000000..d2d5c49ef
--- /dev/null
+++ b/ts/html-filter/BUILD.bazel
@@ -0,0 +1,31 @@
+load("@npm//@bazel/typescript:index.bzl", "ts_library")
+load("//ts:prettier.bzl", "prettier_test")
+load("//ts:eslint.bzl", "eslint_test")
+
+ts_library(
+    name = "html-filter",
+    srcs = glob(["*.ts"]),
+    module_name = "html-filter",
+    tsconfig = "//qt/aqt/data/web/js:tsconfig.json",
+    visibility = ["//visibility:public"],
+    deps = [],
+)
+
+# Tests
+################
+
+prettier_test(
+    name = "format_check",
+    srcs = glob([
+        "*.ts",
+    ]),
+)
+
+eslint_test(
+    name = "eslint",
+    srcs = glob(
+        [
+            "*.ts",
+        ],
+    ),
+)
diff --git a/ts/editor/htmlFilterElement.ts b/ts/html-filter/element.ts
similarity index 85%
rename from ts/editor/htmlFilterElement.ts
rename to ts/html-filter/element.ts
index 90b314de1..ff454959b 100644
--- a/ts/editor/htmlFilterElement.ts
+++ b/ts/html-filter/element.ts
@@ -1,10 +1,10 @@
-import { isNightMode, isHTMLElement } from "./helpers";
-import { removeNode as removeElement } from "./htmlFilterNode";
+import { isHTMLElement, isNightMode } from "./helpers";
+import { removeNode as removeElement } from "./node";
 import {
     filterStylingNightMode,
     filterStylingLightMode,
     filterStylingInternal,
-} from "./htmlFilterStyling";
+} from "./styling";
 
 interface TagsAllowed {
     [tagName: string]: FilterMethod;
@@ -29,13 +29,11 @@ function blockAll(element: Element): void {
     filterOutAttributes(() => true, element);
 }
 
-function blockExcept(attrs: string[]): FilterMethod {
-    return (element: Element) =>
-        filterOutAttributes(
-            (attributeName: string) => !attrs.includes(attributeName),
-            element
-        );
-}
+const blockExcept = (attrs: string[]): FilterMethod => (element: Element): void =>
+    filterOutAttributes(
+        (attributeName: string) => !attrs.includes(attributeName),
+        element
+    );
 
 function unwrapElement(element: Element): void {
     element.outerHTML = element.innerHTML;
@@ -95,7 +93,7 @@ const filterElementTagsAllowed = (tagsAllowed: TagsAllowed) => (
 ): void => {
     const tagName = element.tagName;
 
-    if (tagsAllowed.hasOwnProperty(tagName)) {
+    if (Object.prototype.hasOwnProperty.call(tagsAllowed, tagName)) {
         tagsAllowed[tagName](element);
     } else if (element.innerHTML) {
         removeElement(element);
diff --git a/ts/html-filter/helpers.ts b/ts/html-filter/helpers.ts
new file mode 100644
index 000000000..7945d8942
--- /dev/null
+++ b/ts/html-filter/helpers.ts
@@ -0,0 +1,7 @@
+export function isHTMLElement(elem: Element): elem is HTMLElement {
+    return elem instanceof HTMLElement;
+}
+
+export function isNightMode(): boolean {
+    return document.body.classList.contains("nightMode");
+}
diff --git a/ts/editor/htmlFilter.ts b/ts/html-filter/index.ts
similarity index 94%
rename from ts/editor/htmlFilter.ts
rename to ts/html-filter/index.ts
index 60528c70e..cec3835e2 100644
--- a/ts/editor/htmlFilter.ts
+++ b/ts/html-filter/index.ts
@@ -5,8 +5,8 @@ import {
     filterElementBasic,
     filterElementExtended,
     filterElementInternal,
-} from "./htmlFilterElement";
-import { filterNode } from "./htmlFilterNode";
+} from "./element";
+import { filterNode } from "./node";
 
 enum FilterMode {
     Basic,
diff --git a/ts/editor/htmlFilterNode.ts b/ts/html-filter/node.ts
similarity index 97%
rename from ts/editor/htmlFilterNode.ts
rename to ts/html-filter/node.ts
index ee32dcd4c..735e52fff 100644
--- a/ts/editor/htmlFilterNode.ts
+++ b/ts/html-filter/node.ts
@@ -29,6 +29,6 @@ export const filterNode = (elementFilter: (element: Element) => void) => (
             break;
 
         default:
-            // do nothing
+        // do nothing
     }
 };
diff --git a/ts/editor/htmlFilterStyling.ts b/ts/html-filter/styling.ts
similarity index 93%
rename from ts/editor/htmlFilterStyling.ts
rename to ts/html-filter/styling.ts
index 818e266df..4295f5015 100644
--- a/ts/editor/htmlFilterStyling.ts
+++ b/ts/html-filter/styling.ts
@@ -27,7 +27,8 @@ const stylingInternal: BlockProperties = [
 const allowPropertiesBlockValues = (
     allowBlock: AllowPropertiesBlockValues
 ): StylingPredicate => (property: string, value: string): boolean =>
-    allowBlock.hasOwnProperty(property) && !allowBlock[property].includes(value);
+    Object.prototype.hasOwnProperty.call(allowBlock, property) &&
+    !allowBlock[property].includes(value);
 
 const blockProperties = (block: BlockProperties): StylingPredicate => (
     property: string
diff --git a/ts/tsconfig.json b/ts/tsconfig.json
index eb5ce06d4..9189b9acc 100644
--- a/ts/tsconfig.json
+++ b/ts/tsconfig.json
@@ -7,7 +7,8 @@
         "baseUrl": ".",
         "paths": {
             "anki/*": ["../bazel-bin/ts/lib/*"],
-            "sveltelib/*": ["../bazel-bin/ts/sveltelib/*"]
+            "sveltelib/*": ["../bazel-bin/ts/sveltelib/*"],
+            "html-filter/*": ["../bazel-bin/ts/html-filter/*"]
         },
         "importsNotUsedAsValues": "error",
         "outDir": "dist",