diff --git a/client/utils/parseURLParams.test.js b/client/utils/parseURLParams.test.js
deleted file mode 100644
index 56e0b52611..0000000000
--- a/client/utils/parseURLParams.test.js
+++ /dev/null
@@ -1,51 +0,0 @@
-import { parseUrlParams } from './parseURLParams';
-import { currentP5Version } from '../../common/p5Versions';
-
-describe('parseUrlParams', () => {
-  test('returns defaults when no params are provided', () => {
-    const url = 'https://example.com';
-    const result = parseUrlParams(url);
-
-    expect(result).toEqual({
-      version: currentP5Version,
-      sound: true,
-      preload: false,
-      shapes: false,
-      data: false
-    });
-  });
-
-  test('parses a valid p5 version and falls back for invalid versions', () => {
-    const good = parseUrlParams('https://example.com?version=1.4.0');
-    expect(good.version).toBe('1.4.0');
-
-    const bad = parseUrlParams('https://example.com?version=9.9.9');
-    expect(bad.version).toBe(currentP5Version);
-  });
-
-  test('parses boolean-like params for sound/preload/shapes/data (true variants)', () => {
-    const trueVariants = ['on', 'true', '1', 'ON', 'True'];
-
-    trueVariants.forEach((v) => {
-      const url = `https://example.com?sound=${v}&preload=${v}&shapes=${v}&data=${v}`;
-      const result = parseUrlParams(url);
-      expect(result.sound).toBe(true);
-      expect(result.preload).toBe(true);
-      expect(result.shapes).toBe(true);
-      expect(result.data).toBe(true);
-    });
-  });
-
-  test('parses boolean-like params for sound/preload/shapes/data (false variants)', () => {
-    const falseVariants = ['off', 'false', '0', 'OFF', 'False'];
-
-    falseVariants.forEach((v) => {
-      const url = `https://example.com?sound=${v}&preload=${v}&shapes=${v}&data=${v}`;
-      const result = parseUrlParams(url);
-      expect(result.sound).toBe(false);
-      expect(result.preload).toBe(false);
-      expect(result.shapes).toBe(false);
-      expect(result.data).toBe(false);
-    });
-  });
-});
diff --git a/client/utils/parseURLParams.test.ts b/client/utils/parseURLParams.test.ts
new file mode 100644
index 0000000000..6a6cf8e151
--- /dev/null
+++ b/client/utils/parseURLParams.test.ts
@@ -0,0 +1,118 @@
+import { parseUrlParams, p5VersionStrings } from './parseURLParams';
+import { currentP5Version } from '../../common/p5Versions';
+
+describe('parseUrlParams', () => {
+  describe('default behavior', () => {
+    test('returns defaults when no params are provided', () => {
+      const url = 'https://example.com';
+      const result = parseUrlParams(url);
+
+      expect(result).toEqual({
+        version: currentP5Version,
+        sound: true,
+        preload: false,
+        shapes: false,
+        data: false
+      });
+    });
+
+    test('falls back to defaults for unsupported inputs', () => {
+      const url =
+        'https://example.com?version=A&sound=A&preload=A&shapes=A&data=A';
+      const result = parseUrlParams(url);
+
+      expect(result).toEqual({
+        version: currentP5Version,
+        sound: true,
+        preload: false,
+        shapes: false,
+        data: false
+      });
+    });
+  });
+
+  describe('version parsing', () => {
+    // Uses regex since p5Versions may be updated over time.
+    // Checks to ensure version is valid too.
+
+    test('parses a valid p5 version and falls back for invalid versions', () => {
+      const good = parseUrlParams('https://example.com?version=1.4.0');
+      expect(good.version).toBe('1.4.0');
+
+      const bad = parseUrlParams('https://example.com?version=9.9.9');
+      expect(bad.version).toBe(currentP5Version);
+    });
+
+    test('parses major.minor version 0.5.x to newest patch', () => {
+      const url = 'https://example.com?version=0.5';
+      const result = parseUrlParams(url);
+
+      expect(result.version).toMatch(/^0\.5\.\d+$/);
+      expect(p5VersionStrings).toContain(result.version);
+    });
+
+    test('parses major version 0 to newest 0.x version', () => {
+      const url = 'https://example.com?version=0';
+      const result = parseUrlParams(url);
+
+      expect(result.version).toMatch(/^0\.\d+\.\d+$/);
+      expect(p5VersionStrings).toContain(result.version);
+    });
+
+    test('parses major version 1 to newest 1.x version', () => {
+      const url = 'https://example.com?version=1';
+      const result = parseUrlParams(url);
+      expect(result.version).toMatch(/^1\.\d+\.\d+$/);
+      expect(p5VersionStrings).toContain(result.version);
+    });
+
+    test('parses major.minor version 1.1.x to newest patch', () => {
+      const url = 'https://example.com?version=1.1';
+      const result = parseUrlParams(url);
+      expect(result.version).toMatch(/^1\.1\.\d+$/);
+      expect(p5VersionStrings).toContain(result.version);
+    });
+
+    test('parses major version 2 to newest 2.x version', () => {
+      const url = 'https://example.com?version=2';
+      const result = parseUrlParams(url);
+      expect(result.version).toMatch(/^2\.\d+\.\d+$/);
+      expect(p5VersionStrings).toContain(result.version);
+    });
+
+    test('parses major.minor version 2.0.x to newest patch', () => {
+      const url = 'https://example.com?version=2.0';
+      const result = parseUrlParams(url);
+      expect(result.version).toMatch(/^2\.0\.\d+$/);
+      expect(p5VersionStrings).toContain(result.version);
+    });
+  });
+
+  describe('boolean param parsing', () => {
+    test('parses boolean-like params for sound/preload/shapes/data (true variants)', () => {
+      const trueVariants = ['on', 'true', '1', 'ON', 'True'];
+
+      trueVariants.forEach((v) => {
+        const url = `https://example.com?sound=${v}&preload=${v}&shapes=${v}&data=${v}`;
+        const result = parseUrlParams(url);
+        expect(result.sound).toBe(true);
+        expect(result.preload).toBe(true);
+        expect(result.shapes).toBe(true);
+        expect(result.data).toBe(true);
+      });
+    });
+
+    test('parses boolean-like params for sound/preload/shapes/data (false variants)', () => {
+      const falseVariants = ['off', 'false', '0', 'OFF', 'False'];
+
+      falseVariants.forEach((v) => {
+        const url = `https://example.com?sound=${v}&preload=${v}&shapes=${v}&data=${v}`;
+        const result = parseUrlParams(url);
+        expect(result.sound).toBe(false);
+        expect(result.preload).toBe(false);
+        expect(result.shapes).toBe(false);
+        expect(result.data).toBe(false);
+      });
+    });
+  });
+});
diff --git a/client/utils/parseURLParams.js b/client/utils/parseURLParams.ts
similarity index 70%
rename from client/utils/parseURLParams.js
rename to client/utils/parseURLParams.ts
index 3770c918e3..5e47683818 100644
--- a/client/utils/parseURLParams.js
+++ b/client/utils/parseURLParams.ts
@@ -1,5 +1,13 @@
 import { p5Versions, currentP5Version } from '../../common/p5Versions';
 
+export interface ParsedUrlParams {
+  version: string;
+  sound: boolean;
+  preload: boolean;
+  shapes: boolean;
+  data: boolean;
+}
+
 const DEFAULTS = {
   sound: true,
   preload: false,
@@ -7,12 +15,15 @@ const DEFAULTS = {
   data: false
 };
 
-/**
- * Sorts version strings in descending order and returns the highest version
- * @param {string[]} versions - Array of version strings (e.g., ['1.11.2', '1.11.1'])
- * @returns {string} The highest version from the array
- */
-function getNewestVersion(versions) {
+function getVersionString(
+  item: string | { version: string; label: string }
+): string {
+  return typeof item === 'string' ? item : item.version;
+}
+
+export const p5VersionStrings = p5Versions.map(getVersionString);
+
+function getNewestVersion(versions: string[]): string {
   return versions.sort((a, b) => {
     const pa = a.split('.').map((n) => parseInt(n, 10));
     const pb = b.split('.').map((n) => parseInt(n, 10));
@@ -25,18 +36,18 @@ function getNewestVersion(versions) {
   })[0];
 }
 
-function validateVersion(version) {
+function validateVersion(version: string | null): string {
   if (!version) return currentP5Version;
 
   const ver = String(version).trim();
 
-  if (p5Versions.includes(ver)) return ver;
+  if (p5VersionStrings.includes(ver)) return ver;
 
   // if only major.minor provided like "1.11"
   const majorMinorMatch = /^(\d+)\.(\d+)$/.exec(ver);
   if (majorMinorMatch) {
     const [, major, minor] = majorMinorMatch;
-    const matches = p5Versions.filter((v) => {
+    const matches = p5VersionStrings.filter((v) => {
       const parts = v.split('.');
       return parts[0] === major && parts[1] === minor;
     });
@@ -49,7 +60,7 @@ function validateVersion(version) {
   const majorOnlyMatch = /^(\d+)$/.exec(ver);
   if (majorOnlyMatch) {
     const [, major] = majorOnlyMatch;
-    const matches = p5Versions.filter((v) => v.split('.')[0] === major);
+    const matches = p5VersionStrings.filter((v) => v.split('.')[0] === major);
     if (matches.length) {
       return getNewestVersion(matches);
     }
@@ -58,7 +69,7 @@ function validateVersion(version) {
   return currentP5Version;
 }
 
-function validateBool(value, defaultValue) {
+function validateBool(value: string | null, defaultValue: boolean): boolean {
   if (!value) return defaultValue;
 
   const v = String(value).trim().toLowerCase();
@@ -72,7 +83,7 @@ function validateBool(value, defaultValue) {
   return defaultValue;
 }
 
-export function parseUrlParams(url) {
+export function parseUrlParams(url: string): ParsedUrlParams {
   const params = new URLSearchParams(
     new URL(url, 'https://dummy.origin').search
   );