diff --git a/static/app-strings.json b/static/app-strings.json
index 46815230d..e79a29143 100644
--- a/static/app-strings.json
+++ b/static/app-strings.json
@@ -1307,6 +1307,8 @@
   "Uploading...": "Uploading...",
   "Creating...": "Creating...",
   "Stopped. Duplicate session detected.": "Stopped. Duplicate session detected.",
+  "File being uploaded in another tab or window.": "File being uploaded in another tab or window.",
+  "There are pending uploads.": "There are pending uploads.",
   "Use a URL": "Use a URL",
   "Edit Cover Image": "Edit Cover Image",
   "Cover Image": "Cover Image",
diff --git a/ui/component/app/view.jsx b/ui/component/app/view.jsx
index 3d3f065c1..0ebd85cfe 100644
--- a/ui/component/app/view.jsx
+++ b/ui/component/app/view.jsx
@@ -2,6 +2,7 @@
 import * as PAGES from 'constants/pages';
 import React, { useEffect, useRef, useState, useLayoutEffect } from 'react';
 import { lazyImport } from 'util/lazyImport';
+import { tusUnlockAndNotify, tusHandleTabUpdates } from 'util/tus';
 import classnames from 'classnames';
 import analytics from 'analytics';
 import { setSearchUserId } from 'redux/actions/search';
@@ -231,12 +232,29 @@ function App(props: Props) {
 
   useEffect(() => {
     if (!uploadCount) return;
+
+    const handleUnload = (event) => tusUnlockAndNotify();
     const handleBeforeUnload = (event) => {
       event.preventDefault();
-      event.returnValue = 'magic'; // without setting this to something it doesn't work
+      event.returnValue = __('There are pending uploads.'); // without setting this to something it doesn't work
     };
+
+    window.addEventListener('unload', handleUnload);
     window.addEventListener('beforeunload', handleBeforeUnload);
-    return () => window.removeEventListener('beforeunload', handleBeforeUnload);
+
+    return () => {
+      window.removeEventListener('unload', handleUnload);
+      window.removeEventListener('beforeunload', handleBeforeUnload);
+    };
+  }, [uploadCount]);
+
+  useEffect(() => {
+    if (!uploadCount) return;
+
+    const onStorageUpdate = (e) => tusHandleTabUpdates(e.key);
+    window.addEventListener('storage', onStorageUpdate);
+
+    return () => window.removeEventListener('storage', onStorageUpdate);
   }, [uploadCount]);
 
   // allows user to pause miniplayer using the spacebar without the page scrolling down
diff --git a/ui/component/webUploadList/internal/web-upload-item.jsx b/ui/component/webUploadList/internal/web-upload-item.jsx
index cdf861559..29a4e32e8 100644
--- a/ui/component/webUploadList/internal/web-upload-item.jsx
+++ b/ui/component/webUploadList/internal/web-upload-item.jsx
@@ -5,11 +5,12 @@ import Button from 'component/button';
 import FileThumbnail from 'component/fileThumbnail';
 import * as MODALS from 'constants/modal_types';
 import { serializeFileObj } from 'util/file';
+import { tusIsSessionLocked } from 'util/tus';
 
 type Props = {
   uploadItem: FileUploadItem,
   doPublishResume: (any) => void,
-  doUpdateUploadRemove: (any) => void,
+  doUpdateUploadRemove: (string, any) => void,
   doOpenModal: (string, {}) => void,
 };
 
@@ -18,6 +19,7 @@ export default function WebUploadItem(props: Props) {
   const { params, file, fileFingerprint, progress, status, resumable, uploader } = uploadItem;
 
   const [showFileSelector, setShowFileSelector] = useState(false);
+  const locked = tusIsSessionLocked(params.guid);
 
   function handleFileChange(newFile: WebFile, clearName = true) {
     if (serializeFileObj(newFile) === fileFingerprint) {
@@ -25,7 +27,7 @@ export default function WebUploadItem(props: Props) {
       doPublishResume({ ...params, file_path: newFile });
       if (!params.guid) {
         // Can remove this if-block after January 2022.
-        doUpdateUploadRemove(params);
+        doUpdateUploadRemove('', params);
       }
     } else {
       doOpenModal(MODALS.CONFIRM, {
@@ -52,13 +54,19 @@ export default function WebUploadItem(props: Props) {
             uploader.abort(); // XHR
           }
         }
-        doUpdateUploadRemove(params);
+
+        // The second parameter (params) can be removed after January 2022.
+        doUpdateUploadRemove(params.guid, params);
         closeModal();
       },
     });
   }
 
   function resolveProgressStr() {
+    if (locked) {
+      return __('File being uploaded in another tab or window.');
+    }
+
     if (!uploader) {
       return __('Stopped.');
     }
@@ -85,7 +93,7 @@ export default function WebUploadItem(props: Props) {
   }
 
   function getRetryButton() {
-    if (!resumable) {
+    if (!resumable || locked) {
       return null;
     }
 
@@ -113,7 +121,9 @@ export default function WebUploadItem(props: Props) {
   }
 
   function getCancelButton() {
-    return <Button label={__('Cancel')} button="link" onClick={handleCancel} />;
+    if (!locked) {
+      return <Button label={__('Cancel')} button="link" onClick={handleCancel} />;
+    }
   }
 
   function getFileSelector() {
diff --git a/ui/component/webUploadList/view.jsx b/ui/component/webUploadList/view.jsx
index 89b4ad85e..58c2dba3a 100644
--- a/ui/component/webUploadList/view.jsx
+++ b/ui/component/webUploadList/view.jsx
@@ -7,7 +7,7 @@ type Props = {
   currentUploads: { [key: string]: FileUploadItem },
   uploadCount: number,
   doPublishResume: (any) => void,
-  doUpdateUploadRemove: (any) => void,
+  doUpdateUploadRemove: (string, any) => void,
   doOpenModal: (string, {}) => void,
 };
 
diff --git a/ui/constants/storage.js b/ui/constants/storage.js
new file mode 100644
index 000000000..7b21fea0a
--- /dev/null
+++ b/ui/constants/storage.js
@@ -0,0 +1,3 @@
+// Local Storage keys
+export const TUS_LOCKED_UPLOADS = 'tusLockedUploads';
+export const TUS_REMOVED_UPLOADS = 'tusRemovedUploads';
diff --git a/ui/redux/actions/publish.js b/ui/redux/actions/publish.js
index 471fe1269..591abac2c 100644
--- a/ui/redux/actions/publish.js
+++ b/ui/redux/actions/publish.js
@@ -702,21 +702,28 @@ export function doUpdateUploadAdd(
   };
 }
 
-export const doUpdateUploadProgress = (props: {
-  params: { [key: string]: any },
-  progress?: string,
-  status?: string,
-}) => (dispatch: Dispatch) =>
+export const doUpdateUploadProgress = (props: { guid: string, progress?: string, status?: string }) => (
+  dispatch: Dispatch
+) =>
   dispatch({
     type: ACTIONS.UPDATE_UPLOAD_PROGRESS,
     data: props,
   });
 
-export function doUpdateUploadRemove(params: { [key: string]: any }) {
+/**
+ * doUpdateUploadRemove
+ *
+ * @param guid
+ * @param params Optional. Retain to allow removal of old keys, which are
+ *               derived from `name#channel` instead of using a guid.
+ *               Can be removed after January 2022.
+ * @returns {(function(Dispatch, GetState): void)|*}
+ */
+export function doUpdateUploadRemove(guid: string, params?: { [key: string]: any }) {
   return (dispatch: Dispatch, getState: GetState) => {
     dispatch({
       type: ACTIONS.UPDATE_UPLOAD_REMOVE,
-      data: { params },
+      data: { guid, params },
     });
   };
 }
diff --git a/ui/redux/reducers/publish.js b/ui/redux/reducers/publish.js
index 2d961c1db..8422cfe80 100644
--- a/ui/redux/reducers/publish.js
+++ b/ui/redux/reducers/publish.js
@@ -2,6 +2,7 @@
 import { handleActions } from 'util/redux-utils';
 import { buildURI } from 'util/lbryURI';
 import { serializeFileObj } from 'util/file';
+import { tusLockAndNotify, tusUnlockAndNotify, tusRemoveAndNotify, tusClearRemovedUploads } from 'util/tus';
 import * as ACTIONS from 'constants/action_types';
 import * as THUMBNAIL_STATUSES from 'constants/thumbnail_upload_statuses';
 import { CHANNEL_ANONYMOUS } from 'constants/claim';
@@ -154,10 +155,14 @@ export const publishReducer = handleActions(
       return { ...state, currentUploads };
     },
     [ACTIONS.UPDATE_UPLOAD_PROGRESS]: (state: PublishState, action) => {
-      const { params, progress, status } = action.data;
-      const key = params.guid || getOldKeyFromParam(params);
+      const { guid, progress, status } = action.data;
+      const key = guid;
       const currentUploads = Object.assign({}, state.currentUploads);
 
+      if (guid === 'force--update') {
+        return { ...state, currentUploads };
+      }
+
       if (!currentUploads[key]) {
         return state;
       }
@@ -166,10 +171,16 @@ export const publishReducer = handleActions(
         currentUploads[key].progress = progress;
         delete currentUploads[key].status;
 
-        if (currentUploads[key].uploader.url && !currentUploads[key].params.uploadUrl) {
-          // TUS has finally obtained an upload url from the server. Stash that to check later when resuming.
-          // Ignoring immutable-update requirement (probably doesn't matter to the GUI).
-          currentUploads[key].params.uploadUrl = currentUploads[key].uploader.url;
+        if (currentUploads[key].uploader.url) {
+          // TUS has finally obtained an upload url from the server...
+          if (!currentUploads[key].params.uploadUrl) {
+            // ... Stash that to check later when resuming.
+            // Ignoring immutable-update requirement (probably doesn't matter to the GUI).
+            currentUploads[key].params.uploadUrl = currentUploads[key].uploader.url;
+          }
+
+          // ... lock this tab as the active uploader.
+          tusLockAndNotify(key);
         }
       } else if (status) {
         currentUploads[key].status = status;
@@ -181,11 +192,19 @@ export const publishReducer = handleActions(
       return { ...state, currentUploads };
     },
     [ACTIONS.UPDATE_UPLOAD_REMOVE]: (state: PublishState, action) => {
-      const { params } = action.data;
-      const key = params.guid || getOldKeyFromParam(params);
-      const currentUploads = Object.assign({}, state.currentUploads);
-      delete currentUploads[key];
-      return { ...state, currentUploads };
+      const { guid, params } = action.data;
+      const key = guid || getOldKeyFromParam(params);
+
+      if (state.currentUploads[key]) {
+        const currentUploads = Object.assign({}, state.currentUploads);
+        delete currentUploads[key];
+        tusUnlockAndNotify(key);
+        tusRemoveAndNotify(key);
+
+        return { ...state, currentUploads };
+      }
+
+      return state;
     },
     [ACTIONS.REHYDRATE]: (state: PublishState, action) => {
       if (action && action.payload && action.payload.publish) {
@@ -193,14 +212,20 @@ export const publishReducer = handleActions(
 
         // Cleanup for 'publish::currentUploads'
         if (newPublish.currentUploads) {
-          Object.keys(newPublish.currentUploads).forEach((key) => {
-            const params = newPublish.currentUploads[key].params;
-            if (!params || Object.keys(params).length === 0) {
-              delete newPublish.currentUploads[key];
-            } else {
-              delete newPublish.currentUploads[key].uploader;
-            }
-          });
+          const uploadKeys = Object.keys(newPublish.currentUploads);
+          if (uploadKeys.length > 0) {
+            // Clear uploader and corrupted params
+            uploadKeys.forEach((key) => {
+              const params = newPublish.currentUploads[key].params;
+              if (!params || Object.keys(params).length === 0) {
+                delete newPublish.currentUploads[key];
+              } else {
+                delete newPublish.currentUploads[key].uploader;
+              }
+            });
+          } else {
+            tusClearRemovedUploads();
+          }
         }
 
         return newPublish;
diff --git a/ui/util/storage.js b/ui/util/storage.js
new file mode 100644
index 000000000..54bbf386e
--- /dev/null
+++ b/ui/util/storage.js
@@ -0,0 +1,15 @@
+export function isLocalStorageAvailable() {
+  try {
+    return Boolean(window.localStorage);
+  } catch (e) {
+    return false;
+  }
+}
+
+export function isSessionStorageAvailable() {
+  try {
+    return Boolean(window.sessionStorage);
+  } catch (e) {
+    return false;
+  }
+}
diff --git a/ui/util/tus.js b/ui/util/tus.js
new file mode 100644
index 000000000..557bc553c
--- /dev/null
+++ b/ui/util/tus.js
@@ -0,0 +1,129 @@
+// @flow
+
+/**
+ * This serves a bridge between tabs using localStorage to indicate whether an
+ * upload is currently in progress (locked) or removed.
+ *
+ * An alternative is to sync the redux's 'publish::currentUploads' through the
+ * wallet's sync process, but let's not pollute the wallet for now.
+ */
+
+import { v4 as uuid } from 'uuid';
+import { TUS_LOCKED_UPLOADS, TUS_REMOVED_UPLOADS } from 'constants/storage';
+import { isLocalStorageAvailable } from 'util/storage';
+import { doUpdateUploadRemove, doUpdateUploadProgress } from 'redux/actions/publish';
+
+const localStorageAvailable = isLocalStorageAvailable();
+
+let gTabId: string = '';
+
+function getTabId() {
+  if (!gTabId) {
+    // We want to maximize bootup speed, so only initialize
+    // the tab ID on first use instead when declared.
+    gTabId = uuid();
+  }
+  return gTabId;
+}
+
+// ****************************************************************************
+// Locked
+// ****************************************************************************
+
+function getLockedUploads() {
+  if (localStorageAvailable) {
+    const storedValue = window.localStorage.getItem(TUS_LOCKED_UPLOADS);
+    return storedValue ? JSON.parse(storedValue) : {};
+  }
+  return {};
+}
+
+export function tusIsSessionLocked(guid: string) {
+  const lockedUploads = getLockedUploads();
+  return lockedUploads[guid] && lockedUploads[guid] !== getTabId();
+}
+
+export function tusLockAndNotify(guid: string) {
+  const lockedUploads = getLockedUploads();
+  if (!lockedUploads[guid] && localStorageAvailable) {
+    lockedUploads[guid] = getTabId();
+    window.localStorage.setItem(TUS_LOCKED_UPLOADS, JSON.stringify(lockedUploads));
+  }
+}
+
+/**
+ * tusUnlockAndNotify
+ *
+ * @param guid The upload session to unlock and notify other tabs of.
+ *             Passing 'undefined' will clear all sessions locked by this tab.
+ */
+export function tusUnlockAndNotify(guid?: string) {
+  if (!localStorageAvailable) return;
+
+  const lockedUploads = getLockedUploads();
+
+  if (guid) {
+    delete lockedUploads[guid];
+  } else {
+    const ourTabId = getTabId();
+    const lockedUploadsEntries = Object.entries(lockedUploads);
+    lockedUploadsEntries.forEach(([lockedGuid, tabId]) => {
+      if (tabId === ourTabId) {
+        delete lockedUploads[lockedGuid];
+      }
+    });
+  }
+
+  if (Object.keys(lockedUploads).length > 0) {
+    window.localStorage.setItem(TUS_LOCKED_UPLOADS, JSON.stringify(lockedUploads));
+  } else {
+    window.localStorage.removeItem(TUS_LOCKED_UPLOADS);
+  }
+}
+
+// ****************************************************************************
+// Removed
+// ****************************************************************************
+
+function getRemovedUploads() {
+  if (localStorageAvailable) {
+    const storedValue = window.localStorage.getItem(TUS_REMOVED_UPLOADS);
+    return storedValue ? storedValue.split(',') : [];
+  }
+  return [];
+}
+
+export function tusRemoveAndNotify(guid: string) {
+  if (!localStorageAvailable) return;
+  const removedUploads = getRemovedUploads();
+  removedUploads.push(guid);
+  window.localStorage.setItem(TUS_REMOVED_UPLOADS, removedUploads.join(','));
+}
+
+export function tusClearRemovedUploads() {
+  if (!localStorageAvailable) return;
+  window.localStorage.removeItem(TUS_REMOVED_UPLOADS);
+}
+
+// ****************************************************************************
+// Respond to changes from other tabs.
+// ****************************************************************************
+
+export function tusHandleTabUpdates(storageKey: string) {
+  switch (storageKey) {
+    case TUS_LOCKED_UPLOADS:
+      // The locked IDs are in localStorage, but related GUI is unaware.
+      // Send a redux update to force an update.
+      window.store.dispatch(doUpdateUploadProgress({ guid: 'force--update' }));
+      break;
+
+    case TUS_REMOVED_UPLOADS:
+      // The other tab's store has removed this upload, so it's safe to do the
+      // same without affecting rehydration.
+      if (localStorageAvailable) {
+        const removedUploads = getRemovedUploads();
+        removedUploads.forEach((guid) => window.store.dispatch(doUpdateUploadRemove(guid)));
+      }
+      break;
+  }
+}
diff --git a/web/setup/publish-v1.js b/web/setup/publish-v1.js
index 9a9fe85fe..66195cbf0 100644
--- a/web/setup/publish-v1.js
+++ b/web/setup/publish-v1.js
@@ -49,18 +49,18 @@ export function makeUploadRequest(
     xhr.responseType = 'json';
     xhr.upload.onprogress = (e) => {
       const percentage = ((e.loaded / e.total) * 100).toFixed(2);
-      window.store.dispatch(doUpdateUploadProgress({ params, progress: percentage }));
+      window.store.dispatch(doUpdateUploadProgress({ guid, progress: percentage }));
     };
     xhr.onload = () => {
-      window.store.dispatch(doUpdateUploadRemove(params));
+      window.store.dispatch(doUpdateUploadRemove(guid));
       resolve(xhr);
     };
     xhr.onerror = () => {
-      window.store.dispatch(doUpdateUploadProgress({ params, status: 'error' }));
+      window.store.dispatch(doUpdateUploadProgress({ guid, status: 'error' }));
       reject(new Error(__('There was a problem with your upload. Please try again.')));
     };
     xhr.onabort = () => {
-      window.store.dispatch(doUpdateUploadRemove(params));
+      window.store.dispatch(doUpdateUploadRemove(guid));
     };
 
     if (!isPreview) {
diff --git a/web/setup/publish-v2.js b/web/setup/publish-v2.js
index ba096af93..41eabfb33 100644
--- a/web/setup/publish-v2.js
+++ b/web/setup/publish-v2.js
@@ -69,7 +69,7 @@ export function makeResumableUploadRequest(
         filetype: file instanceof File ? file.type : undefined,
       },
       onShouldRetry: (err, retryAttempt, options) => {
-        window.store.dispatch(doUpdateUploadProgress({ params, status: 'retry' }));
+        window.store.dispatch(doUpdateUploadProgress({ guid, status: 'retry' }));
         const status = err.originalResponse ? err.originalResponse.getStatus() : 0;
         return !inStatusCategory(status, 400);
       },
@@ -78,17 +78,17 @@ export function makeResumableUploadRequest(
         const errMsg = typeof err === 'string' ? err : err.message;
 
         if (status === STATUS_CONFLICT || status === STATUS_LOCKED || errMsg === 'file currently locked') {
-          window.store.dispatch(doUpdateUploadProgress({ params, status: 'conflict' }));
+          window.store.dispatch(doUpdateUploadProgress({ guid, status: 'conflict' }));
           // prettier-ignore
           reject(new Error(`${status}: concurrent upload detected. Uploading the same file from multiple tabs or windows is not allowed.`));
         } else {
-          window.store.dispatch(doUpdateUploadProgress({ params, status: 'error' }));
+          window.store.dispatch(doUpdateUploadProgress({ guid, status: 'error' }));
           reject(new Error(err));
         }
       },
       onProgress: (bytesUploaded, bytesTotal) => {
         const percentage = ((bytesUploaded / bytesTotal) * 100).toFixed(2);
-        window.store.dispatch(doUpdateUploadProgress({ params, progress: percentage }));
+        window.store.dispatch(doUpdateUploadProgress({ guid, progress: percentage }));
       },
       onSuccess: () => {
         let retries = 1;
@@ -101,7 +101,7 @@ export function makeResumableUploadRequest(
           xhr.setRequestHeader(X_LBRY_AUTH_TOKEN, token);
           xhr.responseType = 'json';
           xhr.onload = () => {
-            window.store.dispatch(doUpdateUploadRemove(params));
+            window.store.dispatch(doUpdateUploadRemove(guid));
             resolve(xhr);
           };
           xhr.onerror = () => {
@@ -110,12 +110,12 @@ export function makeResumableUploadRequest(
               analytics.error('notify: first attempt failed (status=0). Retrying after 10s...');
               setTimeout(() => makeNotifyRequest(), 10000); // Auto-retry after 10s delay.
             } else {
-              window.store.dispatch(doUpdateUploadProgress({ params, status: 'error' }));
+              window.store.dispatch(doUpdateUploadProgress({ guid, status: 'error' }));
               reject(new Error(`There was a problem in the processing. Please retry. (${xhr.status})`));
             }
           };
           xhr.onabort = () => {
-            window.store.dispatch(doUpdateUploadRemove(params));
+            window.store.dispatch(doUpdateUploadRemove(guid));
           };
 
           xhr.send(jsonPayload);