diff --git a/src/ui/hash.test.ts b/src/ui/hash.test.ts
index c08a4726bd0..251ff3c5db7 100644
--- a/src/ui/hash.test.ts
+++ b/src/ui/hash.test.ts
@@ -63,7 +63,7 @@ describe('hash', () => {
         expect(map.getCenter().lng).toBe(-1);
         expect(map.getCenter().lat).toBe(3);
         expect(map.getZoom()).toBe(10);
-        expect(map.getBearing() === 0 ? 0 : map.getBearing()).toBe(0);
+        expect(map.getBearing()).toBe(0);
         expect(map.getPitch()).toBe(0);
 
         // map is created with `interactive: false`
@@ -124,7 +124,7 @@ describe('hash', () => {
         expect(map.getCenter().lng).toBe(-1);
         expect(map.getCenter().lat).toBe(3);
         expect(map.getZoom()).toBe(10);
-        expect(map.getBearing() === 0 ? 0 : map.getBearing()).toBe(0);
+        expect(map.getBearing()).toBe(0);
         expect(map.getPitch()).toBe(0);
 
         window.location.hash = '';
@@ -134,7 +134,7 @@ describe('hash', () => {
         expect(map.getCenter().lng).toBe(-1);
         expect(map.getCenter().lat).toBe(3);
         expect(map.getZoom()).toBe(10);
-        expect(map.getBearing() === 0 ? 0 : map.getBearing()).toBe(0);
+        expect(map.getBearing()).toBe(0);
         expect(map.getPitch()).toBe(0);
     });
 
@@ -149,7 +149,7 @@ describe('hash', () => {
         expect(map.getCenter().lng).toBe(-1);
         expect(map.getCenter().lat).toBe(3);
         expect(map.getZoom()).toBe(10);
-        expect(map.getBearing() === 0 ? 0 : map.getBearing()).toBe(0);
+        expect(map.getBearing()).toBe(0);
         expect(map.getPitch()).toBe(0);
 
         window.location.hash = '#map&foo=bar';
@@ -170,12 +170,7 @@ describe('hash', () => {
             .addTo(map);
 
         window.location.hash = '#10/3.00/-1.00';
-
-        const currentHash = hash._getCurrentHash();
-
-        expect(currentHash[0]).toBe('10');
-        expect(currentHash[1]).toBe('3.00');
-        expect(currentHash[2]).toBe('-1.00');
+        expect(hash._getCurrentHash()).toStrictEqual(['10', '3.00', '-1.00']);
     });
 
     test('_getCurrentHash named', () => {
@@ -183,27 +178,50 @@ describe('hash', () => {
             .addTo(map);
 
         window.location.hash = '#map=10/3.00/-1.00&foo=bar';
+        expect(hash._getCurrentHash()).toStrictEqual(['10', '3.00', '-1.00']);
 
-        let currentHash = hash._getCurrentHash();
+        window.location.hash = '#baz&map=10/3.00/-1.00';
+        expect(hash._getCurrentHash()).toStrictEqual(['10', '3.00', '-1.00']);
+    });
 
-        expect(currentHash[0]).toBe('10');
-        expect(currentHash[1]).toBe('3.00');
-        expect(currentHash[2]).toBe('-1.00');
+    describe('getHashString', () => {
+        let hash: Hash;
 
-        window.location.hash = '#baz&map=10/3.00/-1.00';
+        beforeEach(() => {
+            hash = createHash()
+                .addTo(map);
+        });
+
+        test('mapFeedback=true', () => {
+            map.setZoom(10);
+            map.setCenter([2.5, 3.75]);
 
-        currentHash = hash._getCurrentHash();
+            const hashStringWithFeedback = hash.getHashString(true);
+            expect(hashStringWithFeedback).toBe('#/2.5/3.75/10');
 
-        expect(currentHash[0]).toBe('10');
-        expect(currentHash[1]).toBe('3.00');
-        expect(currentHash[2]).toBe('-1.00');
+            map.setBearing(45);
+            map.setPitch(30);
+
+            const hashStringWithRotationAndFeedback = hash.getHashString(true);
+            expect(hashStringWithRotationAndFeedback).toBe('#/2.5/3.75/10/45/30');
+        });
+
+        test('mapFeedback=false', () => {
+            map.setZoom(10);
+            map.setCenter([2.5, 3.75]);
+
+            const hashStringWithoutFeedback = hash.getHashString(false);
+            expect(hashStringWithoutFeedback).toBe('#10/3.75/2.5');
+
+            map.setBearing(45);
+            map.setPitch(30);
+
+            const hashStringWithRotationAndWithoutFeedback = hash.getHashString(false);
+            expect(hashStringWithRotationAndWithoutFeedback).toBe('#10/3.75/2.5/45/30');
+        });
     });
 
     test('_updateHash', () => {
-        function getHash() {
-            return window.location.hash.split('/');
-        }
-
         createHash()
             .addTo(map);
 
@@ -212,36 +230,15 @@ describe('hash', () => {
         map.setZoom(3);
         map.setCenter([2.0, 1.0]);
 
-        expect(window.location.hash).toBeTruthy();
-
-        let newHash = getHash();
-
-        expect(newHash).toHaveLength(3);
-        expect(newHash[0]).toBe('#3');
-        expect(newHash[1]).toBe('1');
-        expect(newHash[2]).toBe('2');
+        expect(window.location.hash).toBe('#3/1/2');
 
         map.setPitch(60);
 
-        newHash = getHash();
-
-        expect(newHash).toHaveLength(5);
-        expect(newHash[0]).toBe('#3');
-        expect(newHash[1]).toBe('1');
-        expect(newHash[2]).toBe('2');
-        expect(newHash[3]).toBe('0');
-        expect(newHash[4]).toBe('60');
+        expect(window.location.hash).toBe('#3/1/2/0/60');
 
         map.setBearing(135);
 
-        newHash = getHash();
-
-        expect(newHash).toHaveLength(5);
-        expect(newHash[0]).toBe('#3');
-        expect(newHash[1]).toBe('1');
-        expect(newHash[2]).toBe('2');
-        expect(newHash[3]).toBe('135');
-        expect(newHash[4]).toBe('60');
+        expect(window.location.hash).toBe('#3/1/2/135/60');
     });
 
     test('_updateHash named', () => {
@@ -279,50 +276,67 @@ describe('hash', () => {
         expect(window.location.hash).toBe('#baz&map=7/1/2/135/60&foo=bar');
     });
 
-    test('_removeHash', () => {
-        const hash = createHash()
-            .addTo(map);
+    describe('_removeHash without a name', () => {
+        let hash: Hash;
 
-        map.setZoom(3);
-        map.setCenter([2.0, 1.0]);
+        beforeEach(() => {
+            hash = createHash()
+                .addTo(map);
+        });
 
-        expect(window.location.hash).toBe('#3/1/2');
+        test('removes hash when hash is only map hash', () => {
+            map.setZoom(3);
+            map.setCenter([2.0, 1.0]);
 
-        hash._removeHash();
+            expect(window.location.hash).toBe('#3/1/2');
 
-        expect(window.location.hash).toBe('');
+            hash._removeHash();
+
+            expect(window.location.hash).toBe('');
+        });
 
-        window.location.hash = '#3/1/2&foo=bar';
+        test('removes hash when hash contains other parameters', () => {
+            window.location.hash = '#3/1/2&foo=bar';
 
-        hash._removeHash();
+            hash._removeHash();
 
-        expect(window.location.hash).toBe('#foo=bar');
+            expect(window.location.hash).toBe('#foo=bar');
+        });
     });
 
-    test('_removeHash named', () => {
-        const hash = createHash('map')
-            .addTo(map);
+    describe('_removeHash with a name', () => {
+        let hash: Hash;
 
-        map.setZoom(3);
-        map.setCenter([2.0, 1.0]);
+        beforeEach(() => {
+            hash = createHash('map')
+                .addTo(map);
+        });
 
-        expect(window.location.hash).toBe('#map=3/1/2');
+        test('removes hash when hash is only map hash', () => {
+            map.setZoom(3);
+            map.setCenter([2.0, 1.0]);
+            expect(window.location.hash).toBe('#map=3/1/2');
 
-        hash._removeHash();
+            hash._removeHash();
 
-        expect(window.location.hash).toBe('');
+            expect(window.location.hash).toBe('');
+        });
 
-        window.location.hash = '#map=3/1/2&foo=bar';
+        test('removes hash when hash contains other parameters at end', () => {
+            window.location.hash = '#map=3/1/2&foo=bar';
 
-        hash._removeHash();
+            hash._removeHash();
 
-        expect(window.location.hash).toBe('#foo=bar');
+            expect(window.location.hash).toBe('#foo=bar');
+        });
 
-        window.location.hash = '#baz&map=7/2/1/135/60&foo=bar';
+        test('removes hash when hash contains other parameters at start and end', () => {
+            window.location.hash = '#baz&map=7/2/1/135/60&foo=bar';
 
-        hash._removeHash();
+            hash._removeHash();
 
-        expect(window.location.hash).toBe('#baz&foo=bar');
+            expect(window.location.hash).toBe('#baz&foo=bar');
+        });
     });
 
     describe('_isValidHash', () => {
@@ -359,6 +373,18 @@ describe('hash', () => {
             expect(hash._isValidHash(hash._getCurrentHash())).toBeFalsy();
         });
 
+        test('invalidate hash, only one value', () => {
+            window.location.hash = '#24';
+
+            expect(hash._isValidHash(hash._getCurrentHash())).toBeFalsy();
+        });
+
+        test('invalidate hash, only two values', () => {
+            window.location.hash = '#24/3.00';
+
+            expect(hash._isValidHash(hash._getCurrentHash())).toBeFalsy();
+        });
+
         test('invalidate hash, zoom greater than maxZoom', () => {
             window.location.hash = '#24/3.00/-1.00';
 
@@ -386,80 +412,269 @@ describe('hash', () => {
 
             expect(hash._isValidHash(hash._getCurrentHash())).toBeFalsy();
         });
+
+        test('invalidate hash, slashes encoded as %2F are not recognised', () => {
+            window.location.hash = '#10%2F3.00%2F-1.00';
+
+            expect(hash._isValidHash(hash._getCurrentHash())).toBeFalsy();
+        });
     });
 
-    test('initialize http://localhost/#', () => {
-        window.location.href = 'http://localhost/#';
-        createHash().addTo(map);
-        map.setZoom(3);
-        expect(window.location.hash).toBe('#3/0/0');
-        expect(window.location.href).toBe('http://localhost/#3/0/0');
-        map.setCenter([2.0, 1.0]);
-        expect(window.location.hash).toBe('#3/1/2');
-        expect(window.location.href).toBe('http://localhost/#3/1/2');
+    describe('initialization', () => {
+        test('http://localhost/#', () => {
+            window.location.href = 'http://localhost/#';
+            createHash().addTo(map);
+            map.setZoom(3);
+            expect(window.location.hash).toBe('#3/0/0');
+            expect(window.location.href).toBe('http://localhost/#3/0/0');
+            map.setCenter([2.0, 1.0]);
+            expect(window.location.hash).toBe('#3/1/2');
+            expect(window.location.href).toBe('http://localhost/#3/1/2');
+        });
+
+        test('http://localhost/##', () => {
+            window.location.href = 'http://localhost/##';
+            createHash().addTo(map);
+            map.setZoom(3);
+            expect(window.location.hash).toBe('#3/0/0');
+            expect(window.location.href).toBe('http://localhost/#3/0/0');
+            map.setCenter([2.0, 1.0]);
+            expect(window.location.hash).toBe('#3/1/2');
+            expect(window.location.href).toBe('http://localhost/#3/1/2');
+        });
+
+        test('http://localhost#', () => {
+            window.location.href = 'http://localhost#';
+            createHash().addTo(map);
+            map.setZoom(4);
+            expect(window.location.hash).toBe('#4/0/0');
+            expect(window.location.href).toBe('http://localhost/#4/0/0');
+            map.setCenter([2.0, 1.0]);
+            expect(window.location.hash).toBe('#4/1/2');
+            expect(window.location.href).toBe('http://localhost/#4/1/2');
+        });
+
+        test('http://localhost/', () => {
+            window.location.href = 'http://localhost/';
+            createHash().addTo(map);
+            map.setZoom(5);
+            expect(window.location.hash).toBe('#5/0/0');
+            expect(window.location.href).toBe('http://localhost/#5/0/0');
+            map.setCenter([2.0, 1.0]);
+            expect(window.location.hash).toBe('#5/1/2');
+            expect(window.location.href).toBe('http://localhost/#5/1/2');
+        });
+
+        test('default value for window.location.href', () => {
+            createHash().addTo(map);
+            map.setZoom(5);
+            expect(window.location.hash).toBe('#5/0/0');
+            expect(window.location.href).toBe('http://localhost/#5/0/0');
+            map.setCenter([2.0, 1.0]);
+            expect(window.location.hash).toBe('#5/1/2');
+            expect(window.location.href).toBe('http://localhost/#5/1/2');
+        });
+
+        test('http://localhost', () => {
+            window.location.href = 'http://localhost';
+            createHash().addTo(map);
+            map.setZoom(4);
+            expect(window.location.hash).toBe('#4/0/0');
+            expect(window.location.href).toBe('http://localhost/#4/0/0');
+            map.setCenter([2.0, 1.0]);
+            expect(window.location.hash).toBe('#4/1/2');
+            expect(window.location.href).toBe('http://localhost/#4/1/2');
+        });
     });
 
-    test('initialize http://localhost/##', () => {
-        window.location.href = 'http://localhost/##';
-        createHash().addTo(map);
-        map.setZoom(3);
-        expect(window.location.hash).toBe('#3/0/0');
-        expect(window.location.href).toBe('http://localhost/#3/0/0');
-        map.setCenter([2.0, 1.0]);
-        expect(window.location.hash).toBe('#3/1/2');
-        expect(window.location.href).toBe('http://localhost/#3/1/2');
+    test('map.remove', () => {
+        const container = window.document.createElement('div');
+        Object.defineProperty(container, 'clientWidth', {value: 512});
+        Object.defineProperty(container, 'clientHeight', {value: 512});
+
+        map.remove();
+
     });
 
-    test('initialize http://localhost#', () => {
-        window.location.href = 'http://localhost#';
-        createHash().addTo(map);
-        map.setZoom(4);
-        expect(window.location.hash).toBe('#4/0/0');
-        expect(window.location.href).toBe('http://localhost/#4/0/0');
-        map.setCenter([2.0, 1.0]);
-        expect(window.location.hash).toBe('#4/1/2');
-        expect(window.location.href).toBe('http://localhost/#4/1/2');
+    test('hash with URL in other parameter does not change', () => {
+        const hash = createHash('map')
+            .addTo(map);
+
+        // Set up hash with URL in another parameter
+        window.location.hash = '#map=10/3/-1&returnUrl=https://example.com&filter=a&b=';
+        map.setZoom(5);
+        map.setCenter([1.0, 2.0]);
+
+        expect(window.location.hash).toBe('#map=5/2/1&returnUrl=https://example.com&filter=a&b=');
+
+        window.location.hash = '#search=foo&map=7/4/2&redirect=/path?query=value';
+        hash._onHashChange();
+        expect(map.getZoom()).toBe(7);
+        expect(map.getCenter().lat).toBe(4);
+        expect(map.getCenter().lng).toBe(2);
     });
 
-    test('initialize http://localhost/', () => {
-        window.location.href = 'http://localhost/';
-        createHash().addTo(map);
+    test('hash with URL+path in other parameter does not change', () => {
+        const hash = createHash('map')
+            .addTo(map);
+
+        // Set up hash with URL in another parameter
+        window.location.hash = '#map=10/3/-1&returnUrl=https://example.com/abcd/ef&filter=a&b=';
         map.setZoom(5);
-        expect(window.location.hash).toBe('#5/0/0');
-        expect(window.location.href).toBe('http://localhost/#5/0/0');
-        map.setCenter([2.0, 1.0]);
-        expect(window.location.hash).toBe('#5/1/2');
-        expect(window.location.href).toBe('http://localhost/#5/1/2');
+        map.setCenter([1.0, 2.0]);
+
+        expect(window.location.hash).toBe('#map=5/2/1&returnUrl=https://example.com/abcd/ef&filter=a&b=');
+
+        window.location.hash = '#search=foo&map=7/4/2&redirect=/path?query=value';
+        hash._onHashChange();
+        expect(map.getZoom()).toBe(7);
+        expect(map.getCenter().lat).toBe(4);
+        expect(map.getCenter().lng).toBe(2);
+    });
+
+    test('hash with trailing ampersand gets removed', () => {
+        const hash = createHash('map')
+            .addTo(map);
+
+        window.location.hash = '#map=10/3/-1&foo=bar&';
+        hash._onHashChange();
+        map.setZoom(11);
+        expect(window.location.hash).toBe('#map=11/3/-1&foo=bar');
+
+    });
+
+    test('hash with double ampersand', () => {
+        const hash = createHash('map')
+            .addTo(map);
+
+        window.location.hash = '#map=10/3/-1&&foo=bar';
+        hash._onHashChange();
+        map.setZoom(12);
+        expect(window.location.hash).toBe('#map=12/3/-1&foo=bar');
+
+    });
+
+    test('hash with leading ampersand removes leading ampersand', () => {
+        const hash = createHash('map')
+            .addTo(map);
+
+        window.location.hash = '#&map=10/3/-1&foo=bar';
+        hash._onHashChange();
+        map.setZoom(13);
+        expect(window.location.hash).toBe('#map=13/3/-1&foo=bar');
+    });
+
+    test('hash with empty parameter values should be invalid', () => {
+        const hash = createHash('map')
+            .addTo(map);
+
+        window.location.hash = '#map=&foo=bar';
+        expect(hash._onHashChange()).toBeFalsy();
+
     });
 
-    test('initialize default value for window.location.href', () => {
-        createHash().addTo(map);
+    test('update to hash with empty parameter values is kept as-is', () => {
+        const hash = createHash('map')
+            .addTo(map);
+
+        window.location.hash = '#map=10/3/-1&empty=';
+        hash._onHashChange();
+        expect(map.getZoom()).toBe(10);
+
         map.setZoom(5);
-        expect(window.location.hash).toBe('#5/0/0');
-        expect(window.location.href).toBe('http://localhost/#5/0/0');
-        map.setCenter([2.0, 1.0]);
-        expect(window.location.hash).toBe('#5/1/2');
-        expect(window.location.href).toBe('http://localhost/#5/1/2');
+        expect(window.location.hash).toBe('#map=5/3/-1&empty=');
     });
 
-    test('initialize http://localhost', () => {
-        window.location.href = 'http://localhost';
-        createHash().addTo(map);
-        map.setZoom(4);
-        expect(window.location.hash).toBe('#4/0/0');
-        expect(window.location.href).toBe('http://localhost/#4/0/0');
-        map.setCenter([2.0, 1.0]);
-        expect(window.location.hash).toBe('#4/1/2');
-        expect(window.location.href).toBe('http://localhost/#4/1/2');
+    describe('geographic boundary values', () => {
+        let hash: Hash;
+
+        beforeEach(() => {
+            hash = createHash()
+                .addTo(map);
+        });
+
+        test('Near south pole, dateline', () => {
+            window.location.hash = '#10/-85.05/-180';
+            hash._onHashChange();
+            expect(map.getZoom()).toBe(10);
+
+            expect(Math.abs(map.getCenter().lat)).toBeCloseTo(85.05, 1);
+            expect(Math.abs(map.getCenter().lng)).toBeCloseTo(180, 2);
+        });
+
+        test('Near north pole, positive dateline', () => {
+            window.location.hash = '#10/85.05/180';
+            hash._onHashChange();
+            expect(map.getZoom()).toBe(10);
+            expect(map.getCenter().lat).toBeCloseTo(85.05, 1);
+            expect(map.getCenter().lng).toBeCloseTo(180, 2);
+        });
+
+        test('Bearing at exact ±180° boundary', () => {
+            window.location.hash = '#10/0/-180/180/60';
+            hash._onHashChange();
+            expect(Math.abs(map.getCenter().lng)).toBeCloseTo(180, 2);
+            expect(map.getPitch()).toBe(60);
+        });
+
+        test('Bearing at exact -180° boundary', () => {
+            map.dragRotate.enable();
+            map.touchZoomRotate.enable();
+            window.location.hash = '#10/0/0/-180';
+            hash._onHashChange();
+            expect(map.getBearing()).toBe(180);
+        });
+
+        test('Zero zoom', () => {
+            window.location.hash = '#0/0/0';
+            hash._onHashChange();
+            expect(map.getZoom()).toBe(0);
+        });
     });
 
-    test('map.remove', () => {
-        const container = window.document.createElement('div');
-        Object.defineProperty(container, 'clientWidth', {value: 512});
-        Object.defineProperty(container, 'clientHeight', {value: 512});
+    test('multiple hash instances on same page', () => {
+        const container1 = window.document.createElement('div');
+        Object.defineProperty(container1, 'clientWidth', {value: 512});
+        Object.defineProperty(container1, 'clientHeight', {value: 512});
+        const map1 = globalCreateMap({container: container1});
 
-        map.remove();
+        const container2 = window.document.createElement('div');
+        Object.defineProperty(container2, 'clientWidth', {value: 512});
+        Object.defineProperty(container2, 'clientHeight', {value: 512});
+        const map2 = globalCreateMap({container: container2});
+
+        const hash1 = createHash('map1').addTo(map1);
+        const hash2 = createHash('map2').addTo(map2);
+
+        // Update first map
+        map1.setZoom(5);
+        map1.setCenter([1.0, 2.0]);
+
+        expect(window.location.hash).toBe('#map1=5/2/1');
+
+        // Update second map
+        map2.setZoom(10);
+        map2.setCenter([3.0, 4.0]);
+
+        expect(window.location.hash).toBe('#map1=5/2/1&map2=10/4/3');
+
+        // Update hash externally and verify both maps respond
+        window.location.hash = '#map1=7/5/6&map2=12/7/8';
+
+        hash1._onHashChange();
+        expect(map1.getZoom()).toBe(7);
+        expect(map1.getCenter().lat).toBe(5);
+        expect(map1.getCenter().lng).toBe(6);
+
+        hash2._onHashChange();
+        expect(map2.getZoom()).toBe(12);
+        expect(map2.getCenter().lat).toBe(7);
+        expect(map2.getCenter().lng).toBe(8);
 
-        expect(map).toBeTruthy();
+        // Clean up
+        hash1.remove();
+        hash2.remove();
+        map1.remove();
+        map2.remove();
     });
 });