diff --git a/libs/remix-ui/search/src/lib/components/Exclude.tsx b/libs/remix-ui/search/src/lib/components/Exclude.tsx
index c334116a6c..9047e26ce7 100644
--- a/libs/remix-ui/search/src/lib/components/Exclude.tsx
+++ b/libs/remix-ui/search/src/lib/components/Exclude.tsx
@@ -18,7 +18,7 @@ export const Exclude = props => {
   return (
     <>
       <div className="search_plugin_find-part pl-3">
-        <label>files to exclude</label>
+        <label className='mt-2'>files to exclude</label>
         <input
           id='search_exclude'
           placeholder="Exclude ie .git/**/*"
diff --git a/libs/remix-ui/search/src/lib/components/Include.tsx b/libs/remix-ui/search/src/lib/components/Include.tsx
index bfd0a33596..1d3f8faf96 100644
--- a/libs/remix-ui/search/src/lib/components/Include.tsx
+++ b/libs/remix-ui/search/src/lib/components/Include.tsx
@@ -14,7 +14,7 @@ export const Include = props => {
   return (
     <>
       <div className="search_plugin_find-part pl-3">
-        <label>files to include</label>
+        <label className='mt-2'>Files to include</label>
         <input
           id='search_include'
           placeholder="Include ie contracts/**/*.sol"
diff --git a/libs/remix-ui/search/src/lib/components/Replace.tsx b/libs/remix-ui/search/src/lib/components/Replace.tsx
index 7bbe7f80a9..33d414d4e7 100644
--- a/libs/remix-ui/search/src/lib/components/Replace.tsx
+++ b/libs/remix-ui/search/src/lib/components/Replace.tsx
@@ -12,7 +12,7 @@ export const Replace = props => {
   return (
     <>
       <div className="search_plugin_find-part">
-      <label>replace in files</label>
+      <label className='d-none'>replace in files</label>
         <input
           id='search_replace'
           placeholder="Replace"
diff --git a/libs/remix-ui/search/src/lib/components/Search.tsx b/libs/remix-ui/search/src/lib/components/Search.tsx
index 61760c3705..a8f32ce4d5 100644
--- a/libs/remix-ui/search/src/lib/components/Search.tsx
+++ b/libs/remix-ui/search/src/lib/components/Search.tsx
@@ -8,6 +8,7 @@ import { Exclude } from './Exclude'
 import { Replace } from './Replace'
 import { OverWriteCheck } from './OverWriteCheck'
 import { FindContainer } from './FindContainer'
+import { Undo } from './Undo'
 
 export const SearchTab = props => {
 
@@ -21,6 +22,7 @@ return (
         <Include></Include>
         <Exclude></Exclude>
         <OverWriteCheck></OverWriteCheck>
+        <Undo></Undo>
         <Results></Results>
       </SearchProvider>
     </div>
diff --git a/libs/remix-ui/search/src/lib/components/Undo.tsx b/libs/remix-ui/search/src/lib/components/Undo.tsx
new file mode 100644
index 0000000000..e44cd23c88
--- /dev/null
+++ b/libs/remix-ui/search/src/lib/components/Undo.tsx
@@ -0,0 +1,29 @@
+import { useDialogDispatchers } from "@remix-ui/app"
+import React from "react"
+import { useContext } from "react"
+import { SearchContext } from "../context/context"
+
+export const Undo = () => {
+    const {
+        state,
+        undoReplace
+    } = useContext(SearchContext)
+    const { alert } = useDialogDispatchers()
+
+
+    const undo = async () => {
+        try{
+            await undoReplace(state.undoBuffer[0])
+        }catch(e){
+            alert({ id: 'undo_error', title: 'Cannot undo this change', message: e.message })
+        }
+    }
+
+    return (<>
+        {state.undoBuffer && state.undoBuffer.length > 0 ?
+            <button onClick={async() => await undo()} className="btn btn-primary btn-block">
+                <div className="fas fa-undo mr-2"></div>
+                Undo changes to {state.undoBuffer[0].path}
+            </button> : null}
+    </>)
+}
\ No newline at end of file
diff --git a/libs/remix-ui/search/src/lib/components/results/ResultItem.tsx b/libs/remix-ui/search/src/lib/components/results/ResultItem.tsx
index 0728d220a1..c0d1ee1ff6 100644
--- a/libs/remix-ui/search/src/lib/components/results/ResultItem.tsx
+++ b/libs/remix-ui/search/src/lib/components/results/ResultItem.tsx
@@ -1,3 +1,4 @@
+import { useDialogDispatchers } from '@remix-ui/app'
 import React, { useContext, useEffect, useRef, useState } from 'react'
 import { SearchContext } from '../../context/context'
 import { SearchResult, SearchResultLine } from '../../types'
@@ -9,7 +10,7 @@ interface ResultItemProps {
 }
 
 export const ResultItem = (props: ResultItemProps) => {
-  const { state, findText, disableForceReload, updateCount } = useContext(
+  const { state, findText, disableForceReload, updateCount, replaceAllInFile } = useContext(
     SearchContext
   )
   const [loading, setLoading] = useState<boolean>(false)
@@ -17,7 +18,7 @@ export const ResultItem = (props: ResultItemProps) => {
   const [toggleExpander, setToggleExpander] = useState<boolean>(false)
   const reloadTimeOut = useRef(null)
   const subscribed = useRef(true)
-
+  const { modal } = useDialogDispatchers()
 
   useEffect(() => {
     reload()
@@ -41,10 +42,28 @@ export const ResultItem = (props: ResultItemProps) => {
   useEffect(() => {
     subscribed.current = true
     return () => {
+      updateCount(0, props.file.filename)
       subscribed.current = false
     }
   }, [])
 
+  const confirmReplace = async () => {
+    setLoading(true)
+    try {
+      await replaceAllInFile(props.file)
+    } catch (e) {
+    }
+    setLoading(false)
+  }
+
+  const replace = async () => {
+    if(state.replaceWithOutConfirmation){
+      confirmReplace()
+    }else{
+      modal({ id: 'confirmreplace', title: 'Replace', message: `Are you sure you want to replace '${state.find}' by '${state.replace}' in ${props.file.filename}?`, okLabel: 'Yes', okFn: confirmReplace, cancelLabel: 'No', cancelFn: ()=>{}, data: null })
+    }
+  }
+
   const reload = () => {
     findText(props.file.filename).then(res => {
       if (subscribed.current) {
@@ -85,7 +104,8 @@ export const ResultItem = (props: ResultItemProps) => {
           {loading ? <div className="loading">Loading...</div> : null}
           {!toggleExpander && !loading ? (
             <div className="p-1 search_plugin_wrap_summary">
-              {lines.map((line, index) => (
+              {state.replaceEnabled? <div onClick={async() => replace()} className='btn btn-primary btn-block mb-2 btn-sm'>Replace all</div>:null}
+              {lines.map((line, index) => (   
                 index < state.maxLines ? 
                 <ResultSummary
                   setLoading={setLoading}
diff --git a/libs/remix-ui/search/src/lib/components/results/Results.tsx b/libs/remix-ui/search/src/lib/components/results/Results.tsx
index 66bee34149..3e5472915a 100644
--- a/libs/remix-ui/search/src/lib/components/results/Results.tsx
+++ b/libs/remix-ui/search/src/lib/components/results/Results.tsx
@@ -6,8 +6,8 @@ export const Results = () => {
   const { state } = useContext(SearchContext)
   return (
     <div data-id='search_results' className='mt-2'>
-      {state.find ? <div className='search_plugin_result_count_number badge badge-pill badge-secondary'>{state.count} results</div>: null}
-      {state.find && state.count >= state.maxResults? <div className='alert alert-warning mt-1'>The result set only contains a subset of all matches<br></br>Please narrow down your search.</div>: null}
+      {state.find ? <div className='search_plugin_result_count_number badge badge-pill badge-secondary'>showing {state.count} results {state.fileCount} in files</div>: null}
+      {state.find && state.clipped? <div className='alert alert-warning mt-1'>The result set only shows a subset of all matches<br></br>Please narrow down your search.</div>: null}
       {state.searchResults &&
         state.searchResults.map((result, index) => {
           return index <state.maxFiles? <ResultItem key={index} file={result} />: null
diff --git a/libs/remix-ui/search/src/lib/components/results/SearchHelper.ts b/libs/remix-ui/search/src/lib/components/results/SearchHelper.ts
index 88ae6b1de1..fb6b096df2 100644
--- a/libs/remix-ui/search/src/lib/components/results/SearchHelper.ts
+++ b/libs/remix-ui/search/src/lib/components/results/SearchHelper.ts
@@ -92,6 +92,9 @@ function getEOL(text) {
     return u > w ? '\n' : '\r\n';
 }
 
+export const replaceAllInFile = (string: string, re:RegExp, newText: string) => {
+  return string.replace(re, newText)
+}
 
 export const replaceTextInLine = (str: string, searchResultLine: SearchResultLineLine, newText: string) => {
     return str
diff --git a/libs/remix-ui/search/src/lib/context/context.tsx b/libs/remix-ui/search/src/lib/context/context.tsx
index 267fa2a92e..9d131ba620 100644
--- a/libs/remix-ui/search/src/lib/context/context.tsx
+++ b/libs/remix-ui/search/src/lib/context/context.tsx
@@ -3,6 +3,7 @@ import { createContext, useReducer } from 'react'
 import {
   findLinesInStringWithMatch,
   getDirectory,
+  replaceAllInFile,
   replaceTextInLine
 } from '../components/results/SearchHelper'
 import { SearchReducer } from '../reducers/Reducer'
@@ -11,7 +12,8 @@ import {
   SearchResult,
   SearchResultLine,
   SearchResultLineLine,
-  SearchingInitialState
+  SearchingInitialState,
+  undoBufferRecord
 } from '../types'
 import { filePathFilter } from '@jsdevtools/file-path-filter'
 import { escapeRegExp } from 'lodash'
@@ -29,7 +31,7 @@ export interface SearchingStateInterface {
   setSearchResults: (value: SearchResult[]) => void
   findText: (path: string) => Promise<SearchResultLine[]>
   hightLightInPath: (result: SearchResult, line: SearchResultLineLine) => void
-  replaceText: (result: SearchResult, line: SearchResultLineLine) => void
+  replaceText: (result: SearchResult, line: SearchResultLineLine) => Promise<void>
   reloadFile: (file: string) => void
   toggleCaseSensitive: () => void
   toggleMatchWholeWord: () => void
@@ -37,6 +39,9 @@ export interface SearchingStateInterface {
   setReplaceWithoutConfirmation: (value: boolean) => void
   disableForceReload: (file: string) => void
   updateCount: (count: number, file: string) => void
+  replaceAllInFile: (result: SearchResult) => Promise<void> 
+  undoReplace: (buffer: undoBufferRecord) => Promise<void>
+  clearUndo: () => void
 }
 
 export const SearchContext = createContext<SearchingStateInterface>(null)
@@ -145,7 +150,7 @@ export const SearchProvider = ({
     updateCount: (count: number, file: string) => {
       dispatch({
         type: 'UPDATE_COUNT',
-        payload: {count, file}
+        payload: { count, file }
       })
     },
     findText: async (path: string) => {
@@ -153,15 +158,9 @@ export const SearchProvider = ({
       try {
         if (state.find.length < 1) return
         const text = await plugin.call('fileManager', 'readFile', path)
-        let flags = 'g'
-        let find = state.find
-        if (!state.casesensitive) flags += 'i'
-        if (!state.useRegExp) find = escapeRegExp(find)
-        if (state.matchWord) find = `\\b${find}\\b`
-        const re = new RegExp(find, flags)
-        const result: SearchResultLine[] = findLinesInStringWithMatch(text, re)
+        const result: SearchResultLine[] = findLinesInStringWithMatch(text, createRegExFromFind())
         return result
-      } catch (e) {}
+      } catch (e) { }
     },
     hightLightInPath: async (
       result: SearchResult,
@@ -180,26 +179,81 @@ export const SearchProvider = ({
           'readFile',
           result.path
         )
-
+        const replaced = replaceTextInLine(content, line, state.replace)
         await plugin.call(
           'fileManager',
           'setFile',
           result.path,
-          replaceTextInLine(content, line, state.replace)
+          replaced
         )
+        setUndoState(content, replaced, result.path)
       } catch (e) {
         throw new Error(e)
       }
+    },
+    replaceAllInFile: async (result: SearchResult) => {
+      await plugin.call('editor', 'discardHighlight')
+      const content = await plugin.call(
+        'fileManager',
+        'readFile',
+        result.path
+      )
+      const replaced = replaceAllInFile(content, createRegExFromFind(), state.replace)
+      await plugin.call(
+        'fileManager',
+        'setFile',
+        result.path,
+        replaced
+      )
+      await plugin.call(
+        'fileManager',
+        'open',
+        result.path
+      )
+      setUndoState(content, replaced, result.path)
+    },
+    undoReplace: async (buffer: undoBufferRecord) => {
+      const content = await plugin.call(
+        'fileManager',
+        'readFile',
+        buffer.path
+      )
+      if (buffer.newContent !== content) {
+        value.clearUndo()
+        throw new Error('Can not undo replace, file has been changed.')
+
+      }
+      await plugin.call(
+        'fileManager',
+        'setFile',
+        buffer.path,
+        buffer.oldContent
+      )
+      await plugin.call(
+        'fileManager',
+        'open',
+        buffer.path
+      )
+      value.clearUndo()
+    },
+    clearUndo: () => {
+      dispatch ({
+        type: 'CLEAR_UNDO',
+        payload: undefined
+      })
     }
   }
 
+
+
   const reloadStateForFile = async (file: string) => {
-      await value.reloadFile(file)
+    await value.reloadFile(file)
   }
 
   useEffect(() => {
     plugin.on('filePanel', 'setWorkspace', () => {
       value.setSearchResults(null)
+      value.clearUndo()
     })
     plugin.on('fileManager', 'fileSaved', async file => {
       await reloadStateForFile(file)
@@ -215,22 +269,46 @@ export const SearchProvider = ({
     const results = []
     paths.split(',').forEach(path => {
       path = path.trim()
-      if(path.startsWith('*.')) path = path.replace(/(\*\.)/g, '**/*.')
-      if(path.endsWith('/*') && !path.endsWith('/**/*')) path = path.replace(/(\*)/g, '**/*.*')
+      if (path.startsWith('*.')) path = path.replace(/(\*\.)/g, '**/*.')
+      if (path.endsWith('/*') && !path.endsWith('/**/*')) path = path.replace(/(\*)/g, '**/*.*')
       results.push(path)
     })
     return results
   }
 
+  const setUndoState = async (oldContent: string, newContent: string, path: string) => {
+    const workspace = await plugin.call('filePanel', 'getCurrentWorkspace')
+    const undo = {
+      oldContent,
+      newContent,
+      path,
+      workspace
+    }
+    dispatch({
+      type: 'SET_UNDO',
+      payload: undo
+    })
+  }
+
+  const createRegExFromFind = () => {
+    let flags = 'g'
+    let find = state.find
+    if (!state.casesensitive) flags += 'i'
+    if (!state.useRegExp) find = escapeRegExp(find)
+    if (state.matchWord) find = `\\b${find}\\b`
+    const re = new RegExp(find, flags)
+    return re
+  }
+
   useEffect(() => {
     if (state.find) {
       (async () => {
         const files = await getDirectory('/', plugin)
         const pathFilter: any = {}
-        if (state.include){
+        if (state.include) {
           pathFilter.include = setGlobalExpression(state.include)
         }
-        if (state.exclude){
+        if (state.exclude) {
           pathFilter.exclude = setGlobalExpression(state.exclude)
         }
         const filteredFiles = files.filter(filePathFilter(pathFilter)).map(file => {
diff --git a/libs/remix-ui/search/src/lib/reducers/Reducer.ts b/libs/remix-ui/search/src/lib/reducers/Reducer.ts
index 47b9cef21f..b40d8ab4c6 100644
--- a/libs/remix-ui/search/src/lib/reducers/Reducer.ts
+++ b/libs/remix-ui/search/src/lib/reducers/Reducer.ts
@@ -1,4 +1,4 @@
-import { Action, SearchingInitialState, SearchState } from "../types"
+import { Action, SearchingInitialState, SearchState, undoBufferRecord } from "../types"
 
 export const SearchReducer = (state: SearchState = SearchingInitialState, action: Action) => {
     switch (action.type) {
@@ -41,21 +41,50 @@ export const SearchReducer = (state: SearchState = SearchingInitialState, action
                 searchResults: action.payload,
                 count: 0
             }
+        case 'SET_UNDO': {
+            const undoState = {
+                newContent : action.payload.newContent,
+                oldContent: action.payload.oldContent,
+                path: action.payload.path,
+                workspace: action.payload.workspace,
+                timeStamp: Date.now()
+            }
+            state.undoBuffer = [undoState]
+            return {
+                ...state,
+            }    
+        }
+        case 'CLEAR_UNDO': {
+            state.undoBuffer = []
+            return {
+                ...state,
+            }
+        }
         case 'UPDATE_COUNT':
             if (state.searchResults) {
                 const findFile = state.searchResults.find(file => file.filename === action.payload.file)
                 let count = 0
+                let fileCount = 0
+                let clipped = false
                 if (findFile) {
                     findFile.count = action.payload.count
                 }
                 state.searchResults.forEach(file => {
-                    if (file.count) {
-                        count += file.count
+                    if (file.count) {          
+                        if(file.count > state.maxLines) {
+                            clipped = true
+                            count += state.maxLines
+                        }else{
+                            count += file.count   
+                        }   
+                        fileCount++
                     }
                 })
                 return {
                     ...state,
-                    count: count
+                    count: count,
+                    fileCount,
+                    clipped
                 }
             } else {
                 return state
diff --git a/libs/remix-ui/search/src/lib/types/index.ts b/libs/remix-ui/search/src/lib/types/index.ts
index 05f2200b1d..aa11435099 100644
--- a/libs/remix-ui/search/src/lib/types/index.ts
+++ b/libs/remix-ui/search/src/lib/types/index.ts
@@ -35,6 +35,14 @@ export interface SearchResult {
     count: number
 }
 
+export interface undoBufferRecord {
+    workspace: string,
+    path: string,
+    newContent: string,
+    timeStamp: number,
+    oldContent: string
+}
+
 export interface SearchState {
     find: string,
     searchResults: SearchResult[],
@@ -48,9 +56,11 @@ export interface SearchState {
     useRegExp: boolean,
     timeStamp: number,
     count: number,
-    maxResults: number
+    fileCount: number,
     maxFiles: number,
     maxLines: number
+    clipped: boolean,
+    undoBuffer: undoBufferRecord[],
 }
 
 export const SearchingInitialState: SearchState = {
@@ -66,7 +76,9 @@ export const SearchingInitialState: SearchState = {
     replaceWithOutConfirmation: false,
     timeStamp: 0,
     count: 0,
-    maxResults: 1500,
-    maxFiles: 100,
-    maxLines: 200
+    fileCount: 0,
+    maxFiles: 5000,
+    maxLines: 5000,
+    clipped: false,
+    undoBuffer: null
 }
\ No newline at end of file