diff --git a/shared/modules/network.utils.test.ts b/shared/modules/network.utils.test.ts
new file mode 100644
index 000000000..ee4ef3f83
--- /dev/null
+++ b/shared/modules/network.utils.test.ts
@@ -0,0 +1,86 @@
+import { MAX_SAFE_CHAIN_ID } from '../constants/network';
+import {
+  isSafeChainId,
+  isPrefixedFormattedHexString,
+  isTokenDetectionEnabledForNetwork,
+} from './network.utils';
+
+describe('network utils', () => {
+  describe('isSafeChainId', () => {
+    it('returns true given an integer greater than 0 and less than or equal to the max safe chain ID', () => {
+      expect(isSafeChainId(3)).toBe(true);
+    });
+
+    it('returns true given the max safe chain ID', () => {
+      expect(isSafeChainId(MAX_SAFE_CHAIN_ID)).toBe(true);
+    });
+
+    it('returns false given something other than an integer', () => {
+      expect(isSafeChainId('not-an-integer')).toBe(false);
+    });
+
+    it('returns false given a negative integer', () => {
+      expect(isSafeChainId(-1)).toBe(false);
+    });
+
+    it('returns false given an integer greater than the max safe chain ID', () => {
+      expect(isSafeChainId(MAX_SAFE_CHAIN_ID + 1)).toBe(false);
+    });
+  });
+
+  describe('isPrefixedFormattedHexString', () => {
+    it('returns true given a string that matches a hex number formatted as a "0x"-prefixed, non-zero, non-zero-padded string', () => {
+      expect(isPrefixedFormattedHexString('0x1')).toBe(true);
+      expect(isPrefixedFormattedHexString('0xa')).toBe(true);
+      expect(isPrefixedFormattedHexString('0xabc123')).toBe(true);
+    });
+
+    it('returns true given a "0x"-prefixed hex string that contains uppercase characters', () => {
+      expect(isPrefixedFormattedHexString('0XABC123')).toBe(true);
+    });
+
+    it('returns false given a "0x"-prefixed hex string that evaluates to zero', () => {
+      expect(isPrefixedFormattedHexString('0x0')).toBe(false);
+    });
+
+    it('returns false given a "0x"-prefixed hex string that does not evaluate to zero but is zero-padded', () => {
+      expect(isPrefixedFormattedHexString('0x01')).toBe(false);
+    });
+
+    it('returns false given a hex number that is simply a string but not "0x"-prefixed', () => {
+      expect(isPrefixedFormattedHexString('abc123')).toBe(false);
+    });
+
+    it('returns false if given something other than a string', () => {
+      expect(isPrefixedFormattedHexString({ something: 'else' })).toBe(false);
+    });
+  });
+
+  describe('isTokenDetectionEnabledForNetwork', () => {
+    it('returns true given the chain ID for Mainnet', () => {
+      expect(isTokenDetectionEnabledForNetwork('0x1')).toBe(true);
+    });
+
+    it('returns true given the chain ID for BSC', () => {
+      expect(isTokenDetectionEnabledForNetwork('0x38')).toBe(true);
+    });
+
+    it('returns true given the chain ID for Polygon', () => {
+      expect(isTokenDetectionEnabledForNetwork('0x89')).toBe(true);
+    });
+
+    it('returns true given the chain ID for Avalanche', () => {
+      expect(isTokenDetectionEnabledForNetwork('0xa86a')).toBe(true);
+    });
+
+    it('returns false given a string that is not the chain ID for Mainnet, BSC, Polygon, or Avalanche', () => {
+      expect(isTokenDetectionEnabledForNetwork('some other chain ID')).toBe(
+        false,
+      );
+    });
+
+    it('returns false given undefined', () => {
+      expect(isTokenDetectionEnabledForNetwork(undefined)).toBe(false);
+    });
+  });
+});
diff --git a/shared/modules/network.utils.js b/shared/modules/network.utils.ts
similarity index 52%
rename from shared/modules/network.utils.js
rename to shared/modules/network.utils.ts
index 05723b3ac..13fca471d 100644
--- a/shared/modules/network.utils.js
+++ b/shared/modules/network.utils.ts
@@ -5,24 +5,22 @@ import { CHAIN_IDS, MAX_SAFE_CHAIN_ID } from '../constants/network';
  * Because some cryptographic libraries we use expect the chain ID to be a
  * number primitive, it must not exceed a certain size.
  *
- * @param {number} chainId - The chain ID to check for safety.
- * @returns {boolean} Whether the given chain ID is safe.
+ * @param chainId - The chain ID to check for safety.
+ * @returns Whether the given chain ID is safe.
  */
-export function isSafeChainId(chainId) {
-  return (
-    Number.isSafeInteger(chainId) && chainId > 0 && chainId <= MAX_SAFE_CHAIN_ID
-  );
+export function isSafeChainId(chainId: unknown): boolean {
+  return isSafeInteger(chainId) && chainId > 0 && chainId <= MAX_SAFE_CHAIN_ID;
 }
 
 /**
  * Checks whether the given value is a 0x-prefixed, non-zero, non-zero-padded,
  * hexadecimal string.
  *
- * @param {any} value - The value to check.
- * @returns {boolean} True if the value is a correctly formatted hex string,
+ * @param value - The value to check.
+ * @returns True if the value is a correctly formatted hex string,
  * false otherwise.
  */
-export function isPrefixedFormattedHexString(value) {
+export function isPrefixedFormattedHexString(value: unknown) {
   if (typeof value !== 'string') {
     return false;
   }
@@ -35,7 +33,7 @@ export function isPrefixedFormattedHexString(value) {
  * @param chainId - ChainID of network
  * @returns Whether the current network supports token detection
  */
-export function isTokenDetectionEnabledForNetwork(chainId) {
+export function isTokenDetectionEnabledForNetwork(chainId: string | undefined) {
   switch (chainId) {
     case CHAIN_IDS.MAINNET:
     case CHAIN_IDS.BSC:
@@ -46,3 +44,14 @@ export function isTokenDetectionEnabledForNetwork(chainId) {
       return false;
   }
 }
+
+/**
+ * Like {@link Number.isSafeInteger}, but types the input as a `number` if it is
+ * indeed a safe integer.
+ *
+ * @param value - The value to check.
+ * @returns True if the value is a safe integer, false otherwise.
+ */
+function isSafeInteger(value: unknown): value is number {
+  return Number.isSafeInteger(value);
+}