diff --git a/src/client/web/package.json b/src/client/web/package.json
index 2a339f0..6596c19 100644
--- a/src/client/web/package.json
+++ b/src/client/web/package.json
@@ -19,6 +19,7 @@
     "@types/assert": "^1.4.2",
     "@types/deep-diff": "^1.0.0",
     "@types/jest": "^27.0.1",
+    "@types/object-hash": "^2.2.1",
     "assert": "^2.0.0",
     "babel-loader": "^8.2.2",
     "deep-diff": "^1.0.2",
@@ -52,6 +53,7 @@
     "css-loader": "^5.0.0",
     "filesize": "^6.1.0",
     "immutable": "^4.0.0-rc.12",
+    "object-hash": "^2.2.0",
     "react": "^16.8.6",
     "react-copy-to-clipboard": "^5.0.1",
     "react-dom": "^16.8.6",
diff --git a/src/client/web/src/app.tsx b/src/client/web/src/app.tsx
index 82177c0..d447c3d 100644
--- a/src/client/web/src/app.tsx
+++ b/src/client/web/src/app.tsx
@@ -14,9 +14,9 @@ window.onerror = (
 ) => {
   const lowerMsg = msg.toLowerCase();
   if (lowerMsg.indexOf("script error") > -1) {
-    ErrorLogger().error(errCorsScript, "Check Browser Console for Detail");
+    ErrorLogger().error("Check Browser Console for Detail");
   }
-  ErrorLogger().error(`${source}:${lineno}:${colno}: ${error.toString()}`, "");
+  ErrorLogger().error(`${source}:${lineno}:${colno}: ${error.toString()}`);
 };
 
 ReactDOM.render(<StateMgr />, document.getElementById("mount"));
diff --git a/src/client/web/src/client/index.ts b/src/client/web/src/client/index.ts
index cf72436..aba783a 100644
--- a/src/client/web/src/client/index.ts
+++ b/src/client/web/src/client/index.ts
@@ -139,6 +139,7 @@ export interface ISettingsClient {
   health: () => Promise<Response>;
   getClientCfg: () => Promise<Response>;
   setClientCfg: (cfg: ClientConfig) => Promise<Response>;
+  reportError: (content: string, version: string) => Promise<Response>;
 }
 
 export interface Response<T = any> {
diff --git a/src/client/web/src/client/settings.ts b/src/client/web/src/client/settings.ts
index 6286bf4..079c193 100644
--- a/src/client/web/src/client/settings.ts
+++ b/src/client/web/src/client/settings.ts
@@ -30,4 +30,15 @@ export class SettingsClient extends BaseClient {
       },
     });
   };
+
+  reportError = (content: string, version: string): Promise<Response> => {
+    return this.do({
+      method: "post",
+      url: `${this.url}/v1/settings/errors`,
+      data: {
+        content,
+        version,
+      },
+    });
+  };
 }
diff --git a/src/client/web/src/client/settings_mock.ts b/src/client/web/src/client/settings_mock.ts
index 99625b1..91bb9a0 100644
--- a/src/client/web/src/client/settings_mock.ts
+++ b/src/client/web/src/client/settings_mock.ts
@@ -7,6 +7,7 @@ export interface SettingsClientResps {
   healthMockResp?: Response;
   setClientCfgMockResp?: Response;
   getClientCfgMockResp?: Response<ClientConfigMsg>;
+  reportErrorResp?: Response;
 }
 
 export const resps = {
@@ -25,9 +26,14 @@ export const resps = {
           position: "clientCfg_bg_position",
           align: "clientCfg_bg_align",
         },
-      }
+      },
     },
   },
+  reportErrorResp: {
+    status: 200,
+    statusText: "",
+    data: {},
+  },
 };
 export class MockSettingsClient {
   private url: string;
@@ -59,4 +65,8 @@ export class MockSettingsClient {
   getClientCfg = (): Promise<Response> => {
     return this.wrapPromise(this.resps.getClientCfgMockResp);
   };
+
+  reportError = (): Promise<Response> => {
+    return this.wrapPromise(this.resps.reportErrorResp);
+  };
 }
diff --git a/src/client/web/src/common/log_error.ts b/src/client/web/src/common/log_error.ts
index d4a3bd2..1fac2e8 100644
--- a/src/client/web/src/common/log_error.ts
+++ b/src/client/web/src/common/log_error.ts
@@ -1,12 +1,27 @@
+import { Map } from "immutable";
+import { sha1 } from "object-hash";
+
 import { ILocalStorage, Storage } from "./localstorage";
 import { ISettingsClient } from "../client";
 import { SettingsClient } from "../client/settings";
+import { ICoreState } from "../components/core_state";
+import { updater } from "../components/state_updater";
+
+const errorVer = "0.0.1";
+const cookieKeyClErrs = "qs_cli_errs";
+
+export interface ClientErrorV001 {
+  version: string;
+  error: string;
+  state: ICoreState;
+}
 
 export interface IErrorLogger {
   setClient: (client: ISettingsClient) => void;
   setStorage: (storage: ILocalStorage) => void;
-  error: (key: string, msg: string) => void;
-  report: () => void;
+  error: (msg: string) => null | Error;
+  report: () => Promise<null | Error>;
+  readErrs: () => Map<string, ClientErrorV001>;
 }
 
 export class ErrorLog {
@@ -25,18 +40,61 @@ export class ErrorLog {
     this.storage = storage;
   }
 
-  error = (key: string, msg: string) => {
-    const existKey = this.storage.get(key);
-    if (existKey === "") {
-      this.storage.set(key, msg);
-    }
+  private getErrorSign = (errMsg: string): string => {
+    return `e:${sha1(errMsg)}`;
   };
 
-  report = () => {
-    // TODO:
-    // check last submitting, and set submit time
-    // report all errors to backend
-    // clean storage
+  readErrs = (): Map<string, ClientErrorV001> => {
+    const errsStr = this.storage.get(cookieKeyClErrs);
+    const errsObj = JSON.parse(errsStr);
+    return Map(errsObj);
+  };
+
+  private writeErrs = (errs: Map<string, ClientErrorV001>) => {
+    const errsObj = errs.toObject();
+    const errsStr = JSON.stringify(errsObj);
+    this.storage.set(cookieKeyClErrs, errsStr);
+  };
+
+  error = (msg: string): null | Error => {
+    try {
+      const sign = this.getErrorSign(msg);
+      const clientErr: ClientErrorV001 = {
+        version: errorVer,
+        error: msg,
+        state: updater().props,
+      };
+      let errs = this.readErrs();
+      if (!errs.has(sign)) {
+        errs = errs.set(sign, clientErr);
+        this.writeErrs(errs);
+      }
+    } catch (err: any) {
+      return Error(`failed to save err log: ${err}`);
+    }
+
+    return null;
+  };
+
+  report = async (): Promise<null | Error> => {
+    try {
+      const errs = this.readErrs();
+
+      for (let sign of errs.keySeq().toArray()) {
+        const err = errs.get(sign);
+        const resp = await this.client.reportError(sign, JSON.stringify(err));
+        if (resp.status !== 200) {
+          return Error(`failed to report error: ${resp.data}`);
+        }
+      }
+
+      // truncate errors
+      this.writeErrs(Map());
+    } catch (e: any) {
+      return Error(e);
+    }
+
+    return null;
   };
 }
 
diff --git a/yarn.lock b/yarn.lock
index a2a6a5c..3c5a17c 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1320,6 +1320,11 @@
   resolved "https://registry.yarnpkg.com/@types/node/-/node-16.9.2.tgz#81f5a039d6ed1941f8cc57506c74e7c2b8fc64b9"
   integrity sha512-ZHty/hKoOLZvSz6BtP1g7tc7nUeJhoCf3flLjh8ZEv1vFKBWHXcnMbJMyN/pftSljNyy0kNW/UqI3DccnBnZ8w==
 
+"@types/object-hash@^2.2.1":
+  version "2.2.1"
+  resolved "https://registry.yarnpkg.com/@types/object-hash/-/object-hash-2.2.1.tgz#67c169f8f033e0b62abbf81df2d00f4598d540b9"
+  integrity sha512-i/rtaJFCsPljrZvP/akBqEwUP2y5cZLOmvO+JaYnz01aPknrQ+hB5MRcO7iqCUsFaYfTG8kGfKUyboA07xeDHQ==
+
 "@types/prettier@^2.1.5":
   version "2.3.2"
   resolved "https://registry.yarnpkg.com/@types/prettier/-/prettier-2.3.2.tgz#fc8c2825e4ed2142473b4a81064e6e081463d1b3"
@@ -3768,6 +3773,11 @@ object-assign@^4.1.1:
   resolved "https://registry.yarnpkg.com/object-assign/-/object-assign-4.1.1.tgz#2109adc7965887cfc05cbbd442cac8bfbb360863"
   integrity sha1-IQmtx5ZYh8/AXLvUQsrIv7s2CGM=
 
+object-hash@^2.2.0:
+  version "2.2.0"
+  resolved "https://registry.yarnpkg.com/object-hash/-/object-hash-2.2.0.tgz#5ad518581eefc443bd763472b8ff2e9c2c0d54a5"
+  integrity sha512-gScRMn0bS5fH+IuwyIFgnh9zBdo4DV+6GhygmWM9HyNJSgS0hScp1f5vjtm7oIIOiT9trXrShAkLFSc2IqKNgw==
+
 object-inspect@^1.11.0, object-inspect@^1.9.0:
   version "1.11.0"
   resolved "https://registry.yarnpkg.com/object-inspect/-/object-inspect-1.11.0.tgz#9dceb146cedd4148a0d9e51ab88d34cf509922b1"