diff --git a/app/assets/javascripts/ide/components/ide_context_bar.vue b/app/assets/javascripts/ide/components/ide_context_bar.vue
index 5a08718e386..78c01272af6 100644
--- a/app/assets/javascripts/ide/components/ide_context_bar.vue
+++ b/app/assets/javascripts/ide/components/ide_context_bar.vue
@@ -2,11 +2,18 @@
 import { mapGetters, mapState, mapActions } from 'vuex';
 import repoCommitSection from './repo_commit_section.vue';
 import icon from '../../vue_shared/components/icon.vue';
+import panelResizer from '../../vue_shared/components/panel_resizer.vue';
 
 export default {
+  data() {
+    return {
+      width: 290,
+    };
+  },
   components: {
     repoCommitSection,
     icon,
+    panelResizer,
   },
   computed: {
     ...mapState([
@@ -18,10 +25,20 @@ export default {
     currentIcon() {
       return this.rightPanelCollapsed ? 'angle-double-left' : 'angle-double-right';
     },
+    maxSize() {
+      return window.innerWidth / 2;
+    },
+    panelStyle() {
+      if (!this.rightPanelCollapsed) {
+        return { width: `${this.width}px` };
+      }
+      return {};
+    },
   },
   methods: {
     ...mapActions([
       'setPanelCollapsedStatus',
+      'setResizingStatus',
     ]),
     toggleCollapsed() {
       this.setPanelCollapsedStatus({
@@ -29,6 +46,12 @@ export default {
         collapsed: !this.rightPanelCollapsed,
       });
     },
+    resizingStarted() {
+      this.setResizingStatus(true);
+    },
+    resizingEnded() {
+      this.setResizingStatus(false);
+    },
   },
 };
 </script>
@@ -39,6 +62,7 @@ export default {
     :class="{
       'is-collapsed': rightPanelCollapsed,
     }"
+    :style="panelStyle"
   >
     <div 
       class="multi-file-commit-panel-section">
@@ -71,5 +95,14 @@ export default {
       <repo-commit-section 
         class=""/>
     </div>
+    <panel-resizer
+      :size.sync="width"
+      :enabled="!rightPanelCollapsed"
+      :start-size="290"
+      :min-size="200"
+      :max-size="maxSize"
+      @resize-start="resizingStarted"
+      @resize-end="resizingEnded"
+      side="left"/>
   </div>
 </template>
diff --git a/app/assets/javascripts/ide/components/ide_side_bar.vue b/app/assets/javascripts/ide/components/ide_side_bar.vue
index 535398d98c2..269f300a04d 100644
--- a/app/assets/javascripts/ide/components/ide_side_bar.vue
+++ b/app/assets/javascripts/ide/components/ide_side_bar.vue
@@ -2,11 +2,18 @@
 import { mapState, mapActions } from 'vuex';
 import projectTree from './ide_project_tree.vue';
 import icon from '../../vue_shared/components/icon.vue';
+import panelResizer from '../../vue_shared/components/panel_resizer.vue';
 
 export default {
+  data() {
+    return {
+      width: 290,
+    };
+  },
   components: {
     projectTree,
     icon,
+    panelResizer,
   },
   computed: {
     ...mapState([
@@ -16,10 +23,20 @@ export default {
     currentIcon() {
       return this.leftPanelCollapsed ? 'angle-double-right' : 'angle-double-left';
     },
+    maxSize() {
+      return window.innerWidth / 2;
+    },
+    panelStyle() {
+      if (!this.leftPanelCollapsed) {
+        return { width: `${this.width}px` };
+      }
+      return {};
+    },
   },
   methods: {
     ...mapActions([
       'setPanelCollapsedStatus',
+      'setResizingStatus',
     ]),
     toggleCollapsed() {
       this.setPanelCollapsedStatus({
@@ -27,6 +44,12 @@ export default {
         collapsed: !this.leftPanelCollapsed,
       });
     },
+    resizingStarted() {
+      this.setResizingStatus(true);
+    },
+    resizingEnded() {
+      this.setResizingStatus(false);
+    },
   },
 };
 </script>
@@ -37,6 +60,7 @@ export default {
       :class="{
         'is-collapsed': leftPanelCollapsed,
       }"
+      :style="panelStyle"
     >
     <div class="multi-file-commit-panel-inner">
       <project-tree
@@ -58,5 +82,14 @@ export default {
         class="collapse-text"
       >Collapse sidebar</span>
     </button>
+    <panel-resizer
+      :size.sync="width"
+      :enabled="!leftPanelCollapsed"
+      :start-size="290"
+      :min-size="200"
+      :max-size="maxSize"
+      @resize-start="resizingStarted"
+      @resize-end="resizingEnded"
+      side="right"/>
   </div>
 </template>
diff --git a/app/assets/javascripts/ide/components/repo_editor.vue b/app/assets/javascripts/ide/components/repo_editor.vue
index 221be4b9074..343fd0a5300 100644
--- a/app/assets/javascripts/ide/components/repo_editor.vue
+++ b/app/assets/javascripts/ide/components/repo_editor.vue
@@ -90,6 +90,11 @@ export default {
     rightPanelCollapsed() {
       this.editor.updateDimensions();
     },
+    panelResizing(isResizing) {
+      if (isResizing === false) {
+        this.editor.updateDimensions();
+      }
+    },
   },
   computed: {
     ...mapGetters([
@@ -99,6 +104,7 @@ export default {
     ...mapState([
       'leftPanelCollapsed',
       'rightPanelCollapsed',
+      'panelResizing',
     ]),
     shouldHideEditor() {
       return this.activeFile.binary && !this.activeFile.raw;
diff --git a/app/assets/javascripts/ide/stores/actions.js b/app/assets/javascripts/ide/stores/actions.js
index c01046c8c76..335882bb6d7 100644
--- a/app/assets/javascripts/ide/stores/actions.js
+++ b/app/assets/javascripts/ide/stores/actions.js
@@ -63,6 +63,10 @@ export const setPanelCollapsedStatus = ({ commit }, { side, collapsed }) => {
   }
 };
 
+export const setResizingStatus = ({ commit }, resizing) => {
+  commit(types.SET_RESIZING_STATUS, resizing);
+};
+
 export const checkCommitStatus = ({ state }) =>
   service
     .getBranchData(state.currentProjectId, state.currentBranchId)
diff --git a/app/assets/javascripts/ide/stores/mutation_types.js b/app/assets/javascripts/ide/stores/mutation_types.js
index 4e3c10972ba..69b218a5e7d 100644
--- a/app/assets/javascripts/ide/stores/mutation_types.js
+++ b/app/assets/javascripts/ide/stores/mutation_types.js
@@ -5,6 +5,7 @@ export const SET_ROOT = 'SET_ROOT';
 export const SET_LAST_COMMIT_DATA = 'SET_LAST_COMMIT_DATA';
 export const SET_LEFT_PANEL_COLLAPSED = 'SET_LEFT_PANEL_COLLAPSED';
 export const SET_RIGHT_PANEL_COLLAPSED = 'SET_RIGHT_PANEL_COLLAPSED';
+export const SET_RESIZING_STATUS = 'SET_RESIZING_STATUS';
 
 // Project Mutation Types
 export const SET_PROJECT = 'SET_PROJECT';
diff --git a/app/assets/javascripts/ide/stores/mutations.js b/app/assets/javascripts/ide/stores/mutations.js
index 2fed9019cb6..03d81be10a1 100644
--- a/app/assets/javascripts/ide/stores/mutations.js
+++ b/app/assets/javascripts/ide/stores/mutations.js
@@ -49,6 +49,11 @@ export default {
       rightPanelCollapsed: collapsed,
     });
   },
+  [types.SET_RESIZING_STATUS](state, resizing) {
+    Object.assign(state, {
+      panelResizing: resizing,
+    });
+  },
   [types.SET_LAST_COMMIT_DATA](state, { entry, lastCommit }) {
     Object.assign(entry.lastCommit, {
       id: lastCommit.commit.id,
diff --git a/app/assets/javascripts/ide/stores/state.js b/app/assets/javascripts/ide/stores/state.js
index 539e382830f..61d12096946 100644
--- a/app/assets/javascripts/ide/stores/state.js
+++ b/app/assets/javascripts/ide/stores/state.js
@@ -19,4 +19,5 @@ export default () => ({
   projects: {},
   leftPanelCollapsed: false,
   rightPanelCollapsed: true,
+  panelResizing: false,
 });
diff --git a/app/assets/javascripts/vue_shared/components/panel_resizer.vue b/app/assets/javascripts/vue_shared/components/panel_resizer.vue
new file mode 100644
index 00000000000..4371534d345
--- /dev/null
+++ b/app/assets/javascripts/vue_shared/components/panel_resizer.vue
@@ -0,0 +1,91 @@
+<script>
+export default {
+  props: {
+    startSize: {
+      type: Number,
+      required: true,
+    },
+    side: {
+      type: String,
+      required: true,
+    },
+    minSize: {
+      type: Number,
+      required: false,
+      default: 0,
+    },
+    maxSize: {
+      type: Number,
+      required: false,
+      default: Number.MAX_VALUE,
+    },
+    enabled: {
+      type: Boolean,
+      required: false,
+      default: true,
+    },
+  },
+  data() {
+    return {
+      size: this.startSize,
+    };
+  },
+  computed: {
+    className() {
+      return `drag${this.side}`;
+    },
+    cursorStyle() {
+      if (this.enabled) {
+        return { cursor: 'ew-resize' };
+      }
+      return {};
+    },
+  },
+  methods: {
+    resetSize(e) {
+      e.preventDefault();
+      this.size = this.startSize;
+      this.$emit('update:size', this.size);
+    },
+    startDrag(e) {
+      if (this.enabled) {
+        e.preventDefault();
+        this.startPos = e.clientX;
+        this.currentStartSize = this.size;
+        document.addEventListener('mousemove', this.drag);
+        document.addEventListener('mouseup', this.endDrag, { once: true });
+        this.$emit('resize-start', this.size);
+      }
+    },
+    drag(e) {
+      e.preventDefault();
+      let moved = e.clientX - this.startPos;
+      if (this.side === 'left') moved = -moved;
+      let newSize = this.currentStartSize + moved;
+      if (newSize < this.minSize) {
+        newSize = this.minSize;
+      } else if (newSize > this.maxSize) {
+        newSize = this.maxSize;
+      }
+      this.size = newSize;
+
+      this.$emit('update:size', newSize);
+    },
+    endDrag(e) {
+      e.preventDefault();
+      document.removeEventListener('mousemove', this.drag);
+      this.$emit('resize-end', this.size);
+    },
+  },
+};
+</script>
+
+<template>
+  <div 
+    class="dragHandle"
+    :class="className"
+    :style="cursorStyle"
+    @mousedown="startDrag"
+    @dblclick="resetSize"
+  ></div>
+</template>
diff --git a/app/assets/stylesheets/pages/repo.scss b/app/assets/stylesheets/pages/repo.scss
index 51cc1729d9a..d01cbadebcc 100644
--- a/app/assets/stylesheets/pages/repo.scss
+++ b/app/assets/stylesheets/pages/repo.scss
@@ -36,10 +36,6 @@
   }
 }
 
-.with-performance-bar .ide-view {
-  height: calc(100vh - #{$header-height});
-}
-
 .ide-file-list {
   flex: 1;
 
@@ -242,12 +238,13 @@ table.table tr td.multi-file-table-name {
 
 .multi-file-commit-panel {
   display: flex;
+  position: relative;
   flex-direction: column;
   height: 100%;
   width: 290px;
   padding: 0;
   background-color: $gray-light;
-  border-left: 1px solid $white-dark;
+  padding-right: 3px;
 
   .projects-sidebar {
     display: flex;
@@ -496,3 +493,30 @@ table.table tr td.multi-file-table-name {
   margin-top: $header-height;
   margin-bottom: 0;
 }
+
+.with-performance-bar {
+  .ide-flash-container.flash-container {
+    margin-top: $header-height + $performance-bar-height;
+  }
+
+  .ide-view {
+    height: calc(100vh - #{$header-height + $performance-bar-height});
+  }
+}
+
+
+.dragHandle {
+  position: absolute;
+  top: 0;
+  bottom: 0;
+  width: 3px;
+  background-color: $white-dark;
+
+  &.dragright {
+    right: 0;
+  }
+
+  &.dragleft {
+    left: 0;
+  }
+}
diff --git a/spec/javascripts/vue_shared/components/panel_resizer_spec.js b/spec/javascripts/vue_shared/components/panel_resizer_spec.js
new file mode 100644
index 00000000000..70ce3dffaba
--- /dev/null
+++ b/spec/javascripts/vue_shared/components/panel_resizer_spec.js
@@ -0,0 +1,59 @@
+import Vue from 'vue';
+import panelResizer from '~/vue_shared/components/panel_resizer.vue';
+import mountComponent from '../../helpers/vue_mount_component_helper';
+
+describe('Panel Resizer component', () => {
+  let vm;
+  let PanelResizer;
+
+  const triggerEvent = (eventName, el = vm.$el, clientX = 0) => {
+    const event = document.createEvent('MouseEvents');
+    event.initMouseEvent(eventName, true, true, window, 1, clientX, 0, clientX, 0, false, false,
+                         false, false, 0, null);
+
+    el.dispatchEvent(event);
+  };
+
+  beforeEach(() => {
+    PanelResizer = Vue.extend(panelResizer);
+  });
+
+  afterEach(() => {
+    vm.$destroy();
+  });
+
+  it('should render a div element with the correct classes and styles', () => {
+    vm = mountComponent(PanelResizer, {
+      startSize: 100,
+      side: 'left',
+    });
+
+    expect(vm.$el.tagName).toEqual('DIV');
+    expect(vm.$el.getAttribute('class')).toBe('dragHandle dragleft');
+    expect(vm.$el.getAttribute('style')).toBe('cursor: ew-resize;');
+  });
+
+  it('should render a div element with the correct classes for a right side panel', () => {
+    vm = mountComponent(PanelResizer, {
+      startSize: 100,
+      side: 'right',
+    });
+
+    expect(vm.$el.tagName).toEqual('DIV');
+    expect(vm.$el.getAttribute('class')).toBe('dragHandle dragright');
+  });
+
+  it('drag the resizer', () => {
+    vm = mountComponent(PanelResizer, {
+      startSize: 100,
+      side: 'left',
+    });
+
+    spyOn(vm, '$emit');
+    triggerEvent('mousedown', vm.$el);
+    triggerEvent('mousemove', document);
+    triggerEvent('mouseup', document);
+    expect(vm.$emit.calls.allArgs()).toEqual([['resize-start', 100], ['update:size', 100], ['resize-end', 100]]);
+    expect(vm.size).toBe(100);
+  });
+});