diff --git a/app/assets/javascripts/pages/projects/compare/index/index.js b/app/assets/javascripts/pages/projects/compare/index/index.js
new file mode 100644
index 0000000000000000000000000000000000000000..b86c9ec442fc1b49578f710c7d2584a80382d92d
--- /dev/null
+++ b/app/assets/javascripts/pages/projects/compare/index/index.js
@@ -0,0 +1,3 @@
+import initCompareSelector from '~/projects/compare';
+
+initCompareSelector();
diff --git a/app/assets/javascripts/projects/compare/components/app.vue b/app/assets/javascripts/projects/compare/components/app.vue
new file mode 100644
index 0000000000000000000000000000000000000000..05bd0f1370b85b3a4c6cd24720be1c8f37e64aaf
--- /dev/null
+++ b/app/assets/javascripts/projects/compare/components/app.vue
@@ -0,0 +1,89 @@
+<script>
+import { GlButton } from '@gitlab/ui';
+import csrf from '~/lib/utils/csrf';
+import RevisionDropdown from './revision_dropdown.vue';
+
+export default {
+  csrf,
+  components: {
+    RevisionDropdown,
+    GlButton,
+  },
+  props: {
+    projectCompareIndexPath: {
+      type: String,
+      required: true,
+    },
+    refsProjectPath: {
+      type: String,
+      required: true,
+    },
+    paramsFrom: {
+      type: String,
+      required: false,
+      default: null,
+    },
+    paramsTo: {
+      type: String,
+      required: false,
+      default: null,
+    },
+    projectMergeRequestPath: {
+      type: String,
+      required: true,
+    },
+    createMrPath: {
+      type: String,
+      required: true,
+    },
+  },
+  methods: {
+    onSubmit() {
+      this.$refs.form.submit();
+    },
+  },
+};
+</script>
+
+<template>
+  <form
+    ref="form"
+    class="form-inline js-requires-input js-signature-container"
+    method="POST"
+    :action="projectCompareIndexPath"
+  >
+    <input :value="$options.csrf.token" type="hidden" name="authenticity_token" />
+    <revision-dropdown
+      :refs-project-path="refsProjectPath"
+      revision-text="Source"
+      params-name="to"
+      :params-branch="paramsTo"
+    />
+    <div class="compare-ellipsis gl-display-inline" data-testid="ellipsis">...</div>
+    <revision-dropdown
+      :refs-project-path="refsProjectPath"
+      revision-text="Target"
+      params-name="from"
+      :params-branch="paramsFrom"
+    />
+    <gl-button category="primary" variant="success" class="gl-ml-3" @click="onSubmit">
+      {{ s__('CompareRevisions|Compare') }}
+    </gl-button>
+    <a
+      v-if="projectMergeRequestPath"
+      :href="projectMergeRequestPath"
+      data-testid="projectMrButton"
+      class="btn btn-default gl-button gl-ml-3"
+    >
+      {{ s__('CompareRevisions|View open merge request') }}
+    </a>
+    <a
+      v-else-if="createMrPath"
+      :href="createMrPath"
+      data-testid="createMrButton"
+      class="btn btn-default gl-button gl-ml-3"
+    >
+      {{ s__('CompareRevisions|Create merge request') }}
+    </a>
+  </form>
+</template>
diff --git a/app/assets/javascripts/projects/compare/components/revision_dropdown.vue b/app/assets/javascripts/projects/compare/components/revision_dropdown.vue
new file mode 100644
index 0000000000000000000000000000000000000000..f657f36322d318c236d34675be12e5ad00622a77
--- /dev/null
+++ b/app/assets/javascripts/projects/compare/components/revision_dropdown.vue
@@ -0,0 +1,145 @@
+<script>
+import { GlDropdown, GlDropdownItem, GlSearchBoxByType, GlDropdownSectionHeader } from '@gitlab/ui';
+import axios from '~/lib/utils/axios_utils';
+import createFlash from '~/flash';
+import { s__ } from '~/locale';
+
+export default {
+  components: {
+    GlDropdown,
+    GlDropdownItem,
+    GlDropdownSectionHeader,
+    GlSearchBoxByType,
+  },
+  props: {
+    refsProjectPath: {
+      type: String,
+      required: true,
+    },
+    revisionText: {
+      type: String,
+      required: true,
+    },
+    paramsName: {
+      type: String,
+      required: true,
+    },
+    paramsBranch: {
+      type: String,
+      required: false,
+      default: null,
+    },
+  },
+  data() {
+    return {
+      branches: [],
+      tags: [],
+      loading: true,
+      searchTerm: '',
+      selectedRevision: this.getDefaultBranch(),
+    };
+  },
+  computed: {
+    filteredBranches() {
+      return this.branches.filter((branch) =>
+        branch.toLowerCase().includes(this.searchTerm.toLowerCase()),
+      );
+    },
+    hasFilteredBranches() {
+      return this.filteredBranches.length;
+    },
+    filteredTags() {
+      return this.tags.filter((tag) => tag.toLowerCase().includes(this.searchTerm.toLowerCase()));
+    },
+    hasFilteredTags() {
+      return this.filteredTags.length;
+    },
+  },
+  mounted() {
+    this.fetchBranchesAndTags();
+  },
+  methods: {
+    fetchBranchesAndTags() {
+      const endpoint = this.refsProjectPath;
+
+      return axios
+        .get(endpoint)
+        .then(({ data }) => {
+          this.branches = data.Branches;
+          this.tags = data.Tags;
+        })
+        .catch(() => {
+          createFlash({
+            message: `${s__(
+              'CompareRevisions|There was an error while updating the branch/tag list. Please try again.',
+            )}`,
+          });
+        })
+        .finally(() => {
+          this.loading = false;
+        });
+    },
+    getDefaultBranch() {
+      return this.paramsBranch || s__('CompareRevisions|Select branch/tag');
+    },
+    onClick(revision) {
+      this.selectedRevision = revision;
+    },
+    onSearchEnter() {
+      this.selectedRevision = this.searchTerm;
+    },
+  },
+};
+</script>
+
+<template>
+  <div class="form-group compare-form-group" :class="`js-compare-${paramsName}-dropdown`">
+    <div class="input-group inline-input-group">
+      <span class="input-group-prepend">
+        <div class="input-group-text">
+          {{ revisionText }}
+        </div>
+      </span>
+      <input type="hidden" :name="paramsName" :value="selectedRevision" />
+      <gl-dropdown
+        class="gl-flex-grow-1 gl-flex-basis-0 gl-min-w-0 gl-font-monospace"
+        toggle-class="form-control compare-dropdown-toggle js-compare-dropdown gl-min-w-0 gl-rounded-top-left-none! gl-rounded-bottom-left-none!"
+        :text="selectedRevision"
+        header-text="Select Git revision"
+        :loading="loading"
+      >
+        <template #header>
+          <gl-search-box-by-type
+            v-model.trim="searchTerm"
+            :placeholder="s__('CompareRevisions|Filter by Git revision')"
+            @keyup.enter="onSearchEnter"
+          />
+        </template>
+        <gl-dropdown-section-header v-if="hasFilteredBranches">
+          {{ s__('CompareRevisions|Branches') }}
+        </gl-dropdown-section-header>
+        <gl-dropdown-item
+          v-for="(branch, index) in filteredBranches"
+          :key="`branch${index}`"
+          is-check-item
+          :is-checked="selectedRevision === branch"
+          @click="onClick(branch)"
+        >
+          {{ branch }}
+        </gl-dropdown-item>
+        <gl-dropdown-section-header v-if="hasFilteredTags">
+          {{ s__('CompareRevisions|Tags') }}
+        </gl-dropdown-section-header>
+        <gl-dropdown-item
+          v-for="(tag, index) in filteredTags"
+          :key="`tag${index}`"
+          is-check-item
+          :is-checked="selectedRevision === tag"
+          @click="onClick(tag)"
+        >
+          {{ tag }}
+        </gl-dropdown-item>
+      </gl-dropdown>
+    </div>
+  </div>
+</template>
diff --git a/app/assets/javascripts/projects/compare/index.js b/app/assets/javascripts/projects/compare/index.js
new file mode 100644
index 0000000000000000000000000000000000000000..4337eecb667be6a24cf631f8c3050e98d9e4e812
--- /dev/null
+++ b/app/assets/javascripts/projects/compare/index.js
@@ -0,0 +1,33 @@
+import Vue from 'vue';
+import CompareApp from './components/app.vue';
+
+export default function init() {
+  const el = document.getElementById('js-compare-selector');
+  const {
+    refsProjectPath,
+    paramsFrom,
+    paramsTo,
+    projectCompareIndexPath,
+    projectMergeRequestPath,
+    createMrPath,
+  } = el.dataset;
+
+  return new Vue({
+    el,
+    components: {
+      CompareApp,
+    },
+    render(createElement) {
+      return createElement(CompareApp, {
+        props: {
+          refsProjectPath,
+          paramsFrom,
+          paramsTo,
+          projectCompareIndexPath,
+          projectMergeRequestPath,
+          createMrPath,
+        },
+      });
+    },
+  });
+}
diff --git a/app/assets/stylesheets/pages/projects.scss b/app/assets/stylesheets/pages/projects.scss
index 1648c5e0a427300115b2b934611a475880ebc09c..8251cdb9bbba6bcdd8bab8b202c29ae59a7af42a 100644
--- a/app/assets/stylesheets/pages/projects.scss
+++ b/app/assets/stylesheets/pages/projects.scss
@@ -992,6 +992,20 @@ pre.light-well {
       width: auto;
     }
   }
+
+  // Remove once gitlab/ui solution is implemented:
+  // https://gitlab.com/gitlab-org/gitlab-ui/-/issues/1157
+  // https://gitlab.com/gitlab-org/gitlab/-/issues/300405
+  .gl-search-box-by-type-input {
+    width: 100%;
+  }
+
+  // Remove once gitlab/ui solution is implemented
+  // https://gitlab.com/gitlab-org/gitlab-ui/-/issues/1158
+  // https://gitlab.com/gitlab-org/gitlab/-/issues/300405
+  .gl-new-dropdown-button-text {
+    @include str-truncated;
+  }
 }
 
 .clearable-input {
diff --git a/app/views/projects/compare/index.html.haml b/app/views/projects/compare/index.html.haml
index e45ea209e8c0508ad9592a9716784d912c66f79e..3f9aa24a569eb2059b38bb1ed80b68f32371e1a5 100644
--- a/app/views/projects/compare/index.html.haml
+++ b/app/views/projects/compare/index.html.haml
@@ -13,4 +13,8 @@
   = html_escape(_("Changes are shown as if the %{b_open}source%{b_close} revision was being merged into the %{b_open}target%{b_close} revision.")) % { b_open: '<b>'.html_safe, b_close: '</b>'.html_safe }
 
 .prepend-top-20
-  = render "form"
+  #js-compare-selector{ data: { project_compare_index_path: project_compare_index_path(@project),
+    refs_project_path: refs_project_path(@project),
+    params_from: params[:from], params_to: params[:to],
+    project_merge_request_path: @merge_request.present? ? project_merge_request_path(@project, @merge_request) : '',
+    create_mr_path: create_mr_button? ? create_mr_path : '' } }
diff --git a/locale/gitlab.pot b/locale/gitlab.pot
index 91300f92f8053310029a309fc5fed5eef5a97639..7e9a9c339501924d0c551a17fbddb8efaa472696 100644
--- a/locale/gitlab.pot
+++ b/locale/gitlab.pot
@@ -7343,6 +7343,30 @@ msgstr ""
 msgid "CompareBranches|There isn't anything to compare."
 msgstr ""
 
+msgid "CompareRevisions|Branches"
+msgstr ""
+
+msgid "CompareRevisions|Compare"
+msgstr ""
+
+msgid "CompareRevisions|Create merge request"
+msgstr ""
+
+msgid "CompareRevisions|Filter by Git revision"
+msgstr ""
+
+msgid "CompareRevisions|Select branch/tag"
+msgstr ""
+
+msgid "CompareRevisions|Tags"
+msgstr ""
+
+msgid "CompareRevisions|There was an error while updating the branch/tag list. Please try again."
+msgstr ""
+
+msgid "CompareRevisions|View open merge request"
+msgstr ""
+
 msgid "Complete"
 msgstr ""
 
diff --git a/spec/features/projects/commits/user_browses_commits_spec.rb b/spec/features/projects/commits/user_browses_commits_spec.rb
index 596b47737166abffde4ab5c1292e630681dcda0a..4894e2b7f3e2a55466d1096c6195b9920ab08d75 100644
--- a/spec/features/projects/commits/user_browses_commits_spec.rb
+++ b/spec/features/projects/commits/user_browses_commits_spec.rb
@@ -203,10 +203,11 @@
 
       context 'when click the compare tab' do
         before do
+          wait_for_requests
           click_link('Compare')
         end
 
-        it 'does not render create merge request button' do
+        it 'does not render create merge request button', :js do
           expect(page).not_to have_link 'Create merge request'
         end
       end
@@ -236,10 +237,11 @@
 
         context 'when click the compare tab' do
           before do
+            wait_for_requests
             click_link('Compare')
           end
 
-          it 'renders create merge request button' do
+          it 'renders create merge request button', :js do
             expect(page).to have_link 'Create merge request'
           end
         end
@@ -276,10 +278,11 @@
 
         context 'when click the compare tab' do
           before do
+            wait_for_requests
             click_link('Compare')
           end
 
-          it 'renders button to the merge request' do
+          it 'renders button to the merge request', :js do
             expect(page).not_to have_link 'Create merge request'
             expect(page).to have_link 'View open merge request', href: project_merge_request_path(project, merge_request)
           end
diff --git a/spec/features/projects/compare_spec.rb b/spec/features/projects/compare_spec.rb
index e387ea4d473b0cc7b54ce9520d9fb797ad37cb73..64e9968061c533c08a74d1cb651ee45522c812c9 100644
--- a/spec/features/projects/compare_spec.rb
+++ b/spec/features/projects/compare_spec.rb
@@ -17,10 +17,10 @@
         visit project_compare_index_path(project, from: 'master', to: 'master')
 
         select_using_dropdown 'from', 'feature'
-        expect(find('.js-compare-from-dropdown .dropdown-toggle-text')).to have_content('feature')
+        expect(find('.js-compare-from-dropdown .gl-new-dropdown-button-text')).to have_content('feature')
 
         select_using_dropdown 'to', 'binary-encoding'
-        expect(find('.js-compare-to-dropdown .dropdown-toggle-text')).to have_content('binary-encoding')
+        expect(find('.js-compare-to-dropdown .gl-new-dropdown-button-text')).to have_content('binary-encoding')
 
         click_button 'Compare'
 
@@ -32,8 +32,8 @@
     it "pre-populates fields" do
       visit project_compare_index_path(project, from: "master", to: "master")
 
-      expect(find(".js-compare-from-dropdown .dropdown-toggle-text")).to have_content("master")
-      expect(find(".js-compare-to-dropdown .dropdown-toggle-text")).to have_content("master")
+      expect(find(".js-compare-from-dropdown .gl-new-dropdown-button-text")).to have_content("master")
+      expect(find(".js-compare-to-dropdown .gl-new-dropdown-button-text")).to have_content("master")
     end
 
     it_behaves_like 'compares branches'
@@ -99,7 +99,7 @@
 
       find(".js-compare-from-dropdown .compare-dropdown-toggle").click
 
-      expect(find(".js-compare-from-dropdown .dropdown-content")).to have_selector("li", count: 3)
+      expect(find(".js-compare-from-dropdown .gl-new-dropdown-contents")).to have_selector('li.gl-new-dropdown-item', count: 1)
     end
 
     context 'when commit has overflow', :js do
@@ -125,10 +125,10 @@
       visit project_compare_index_path(project, from: "master", to: "master")
 
       select_using_dropdown "from", "v1.0.0"
-      expect(find(".js-compare-from-dropdown .dropdown-toggle-text")).to have_content("v1.0.0")
+      expect(find(".js-compare-from-dropdown .gl-new-dropdown-button-text")).to have_content("v1.0.0")
 
       select_using_dropdown "to", "v1.1.0"
-      expect(find(".js-compare-to-dropdown .dropdown-toggle-text")).to have_content("v1.1.0")
+      expect(find(".js-compare-to-dropdown .gl-new-dropdown-button-text")).to have_content("v1.1.0")
 
       click_button "Compare"
       expect(page).to have_content "Commits"
@@ -136,19 +136,22 @@
   end
 
   def select_using_dropdown(dropdown_type, selection, commit: false)
+    wait_for_requests
+
     dropdown = find(".js-compare-#{dropdown_type}-dropdown")
     dropdown.find(".compare-dropdown-toggle").click
     # find input before using to wait for the inputs visibility
     dropdown.find('.dropdown-menu')
     dropdown.fill_in("Filter by Git revision", with: selection)
+
     wait_for_requests
 
     if commit
-      dropdown.find('input[type="search"]').send_keys(:return)
+      dropdown.find('.gl-search-box-by-type-input').send_keys(:return)
     else
       # find before all to wait for the items visibility
-      dropdown.find("a[data-ref=\"#{selection}\"]", match: :first)
-      dropdown.all("a[data-ref=\"#{selection}\"]").last.click
+      dropdown.find(".js-compare-#{dropdown_type}-dropdown .dropdown-item", text: selection, match: :first)
+      dropdown.all(".js-compare-#{dropdown_type}-dropdown .dropdown-item", text: selection).first.click
     end
   end
 end
diff --git a/spec/frontend/projects/compare/components/app_spec.js b/spec/frontend/projects/compare/components/app_spec.js
new file mode 100644
index 0000000000000000000000000000000000000000..e265055ef1be9c42a395458ca207c259bffae037
--- /dev/null
+++ b/spec/frontend/projects/compare/components/app_spec.js
@@ -0,0 +1,116 @@
+import { shallowMount } from '@vue/test-utils';
+import { GlButton } from '@gitlab/ui';
+import CompareApp from '~/projects/compare/components/app.vue';
+import RevisionDropdown from '~/projects/compare/components/revision_dropdown.vue';
+
+jest.mock('~/lib/utils/csrf', () => ({ token: 'mock-csrf-token' }));
+
+const projectCompareIndexPath = 'some/path';
+const refsProjectPath = 'some/refs/path';
+const paramsFrom = 'master';
+const paramsTo = 'master';
+
+describe('CompareApp component', () => {
+  let wrapper;
+
+  const createComponent = (props = {}) => {
+    wrapper = shallowMount(CompareApp, {
+      propsData: {
+        projectCompareIndexPath,
+        refsProjectPath,
+        paramsFrom,
+        paramsTo,
+        projectMergeRequestPath: '',
+        createMrPath: '',
+        ...props,
+      },
+    });
+  };
+
+  afterEach(() => {
+    wrapper.destroy();
+    wrapper = null;
+  });
+
+  beforeEach(() => {
+    createComponent();
+  });
+
+  it('renders component with prop', () => {
+    expect(wrapper.props()).toEqual(
+      expect.objectContaining({
+        projectCompareIndexPath,
+        refsProjectPath,
+        paramsFrom,
+        paramsTo,
+      }),
+    );
+  });
+
+  it('contains the correct form attributes', () => {
+    expect(wrapper.attributes('action')).toBe(projectCompareIndexPath);
+    expect(wrapper.attributes('method')).toBe('POST');
+  });
+
+  it('has input with csrf token', () => {
+    expect(wrapper.find('input[name="authenticity_token"]').attributes('value')).toBe(
+      'mock-csrf-token',
+    );
+  });
+
+  it('has ellipsis', () => {
+    expect(wrapper.find('[data-testid="ellipsis"]').exists()).toBe(true);
+  });
+
+  it('render Source and Target BranchDropdown components', () => {
+    const branchDropdowns = wrapper.findAll(RevisionDropdown);
+
+    expect(branchDropdowns.length).toBe(2);
+    expect(branchDropdowns.at(0).props('revisionText')).toBe('Source');
+    expect(branchDropdowns.at(1).props('revisionText')).toBe('Target');
+  });
+
+  describe('compare button', () => {
+    const findCompareButton = () => wrapper.find(GlButton);
+
+    it('renders button', () => {
+      expect(findCompareButton().exists()).toBe(true);
+    });
+
+    it('submits form', () => {
+      findCompareButton().vm.$emit('click');
+      expect(wrapper.find('form').element.submit).toHaveBeenCalled();
+    });
+
+    it('has compare text', () => {
+      expect(findCompareButton().text()).toBe('Compare');
+    });
+  });
+
+  describe('merge request buttons', () => {
+    const findProjectMrButton = () => wrapper.find('[data-testid="projectMrButton"]');
+    const findCreateMrButton = () => wrapper.find('[data-testid="createMrButton"]');
+
+    it('does not have merge request buttons', () => {
+      createComponent();
+      expect(findProjectMrButton().exists()).toBe(false);
+      expect(findCreateMrButton().exists()).toBe(false);
+    });
+
+    it('has "View open merge request" button', () => {
+      createComponent({
+        projectMergeRequestPath: 'some/project/merge/request/path',
+      });
+      expect(findProjectMrButton().exists()).toBe(true);
+      expect(findCreateMrButton().exists()).toBe(false);
+    });
+
+    it('has "Create merge request" button', () => {
+      createComponent({
+        createMrPath: 'some/create/create/mr/path',
+      });
+      expect(findProjectMrButton().exists()).toBe(false);
+      expect(findCreateMrButton().exists()).toBe(true);
+    });
+  });
+});
diff --git a/spec/frontend/projects/compare/components/revision_dropdown_spec.js b/spec/frontend/projects/compare/components/revision_dropdown_spec.js
new file mode 100644
index 0000000000000000000000000000000000000000..c9e87fb904dcd9cb5a15febfcfae1ecf5d78d089
--- /dev/null
+++ b/spec/frontend/projects/compare/components/revision_dropdown_spec.js
@@ -0,0 +1,92 @@
+import { shallowMount } from '@vue/test-utils';
+import AxiosMockAdapter from 'axios-mock-adapter';
+import { GlDropdown } from '@gitlab/ui';
+import axios from '~/lib/utils/axios_utils';
+import RevisionDropdown from '~/projects/compare/components/revision_dropdown.vue';
+import createFlash from '~/flash';
+
+const defaultProps = {
+  refsProjectPath: 'some/refs/path',
+  revisionText: 'Target',
+  paramsName: 'from',
+  paramsBranch: 'master',
+};
+
+jest.mock('~/flash');
+
+describe('RevisionDropdown component', () => {
+  let wrapper;
+  let axiosMock;
+
+  const createComponent = (props = {}) => {
+    wrapper = shallowMount(RevisionDropdown, {
+      propsData: {
+        ...defaultProps,
+        ...props,
+      },
+    });
+  };
+
+  beforeEach(() => {
+    axiosMock = new AxiosMockAdapter(axios);
+  });
+
+  afterEach(() => {
+    wrapper.destroy();
+    axiosMock.restore();
+  });
+
+  const findGlDropdown = () => wrapper.find(GlDropdown);
+
+  it('sets hidden input', () => {
+    createComponent();
+    expect(wrapper.find('input[type="hidden"]').attributes('value')).toBe(
+      defaultProps.paramsBranch,
+    );
+  });
+
+  it('update the branches on success', async () => {
+    const Branches = ['branch-1', 'branch-2'];
+    const Tags = ['tag-1', 'tag-2', 'tag-3'];
+
+    axiosMock.onGet(defaultProps.refsProjectPath).replyOnce(200, {
+      Branches,
+      Tags,
+    });
+
+    createComponent();
+
+    await axios.waitForAll();
+
+    expect(wrapper.vm.branches).toEqual(Branches);
+    expect(wrapper.vm.tags).toEqual(Tags);
+  });
+
+  it('shows flash message on error', async () => {
+    axiosMock.onGet('some/invalid/path').replyOnce(404);
+
+    createComponent();
+
+    await wrapper.vm.fetchBranchesAndTags();
+    expect(createFlash).toHaveBeenCalled();
+  });
+
+  describe('GlDropdown component', () => {
+    it('renders props', () => {
+      createComponent();
+      expect(wrapper.props()).toEqual(expect.objectContaining(defaultProps));
+    });
+
+    it('display default text', () => {
+      createComponent({
+        paramsBranch: null,
+      });
+      expect(findGlDropdown().props('text')).toBe('Select branch/tag');
+    });
+
+    it('display params branch text', () => {
+      createComponent();
+      expect(findGlDropdown().props('text')).toBe(defaultProps.paramsBranch);
+    });
+  });
+});